General science Rapid revision for jkssb CSSD Attendent Nursing Grade III

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​Unit-VI: GENERAL SCIENCE (17 Marks)

​(i) Gravitation / Heat / Light / Matter / Acids / Salts / Elements / Cells.
​(ii) Various sources of energy; conventional sources of energy; improvement in technology for using conventional source of energy (Biomass and wind energy).
​(iii) Non-conventional sources of energy (Solar energy, Energy from sea).
​(iv) Physical properties of metals and non-metals.
​(v) Chemical properties of metals like action of water, air, acids, salts; Reactivity series of metals.
​(vi) Occurance of metals; their extraction, enrichment of ores. Extraction of metals in accordance with activity series; refining of metals.
​(vii) Life processes: Nutrition and its types, Respiration, Transportation of water, food and minerals in plants, Excretion with reference to plants and animals.
​(viii) Environmental pollution.
​(ix) Ecosystem – Its components, Food chains and Food webs.
​(x) Ozone layer, its depletion, Green House Effect.
​(xi) Mendel's contribution and experiments on pea plant.
​(xii) Types of reproduction in Plants and Animals.
​(xiii) Classification of Plants and Animals.

CHAPTER 1 : GRAVITATION (JKSSB General Science)

Weightage for JKSSB Exam

Questions are frequently asked on:

Universal Law of Gravitation
Newton's Laws
Acceleration due to Gravity (g)
Mass vs Weight
Free Fall
Thrust & Pressure
Buoyancy
Archimedes' Principle
Relative Density

Floatation

QUICK REVISION (100+ One-Liner Points)

Universal Gravitation

  1. Sir Isaac Newton proposed the Universal Law of Gravitation.

  2. Every object attracts every other object in the universe.

  3. Gravitational force acts along the line joining two bodies.

  4. Gravity is always attractive.

  5. Gravitational force never becomes zero.

  6. Gravity is the weakest fundamental force.

  7. Gravitational force is a non-contact force.

  8. Gravity acts between all objects having mass.

  9. Gravitational force depends upon masses of both bodies.

  10. It decreases rapidly with distance.

  11. Force is inversely proportional to square of distance.

  12. SI unit of force is Newton (N).

  13. Gravity keeps planets in their orbits.

  14. Gravity keeps satellites revolving around Earth.

  15. Gravity gives weight to every object.

  16. Gravity is responsible for tides.

  17. Moon's gravity causes ocean tides.

  18. Earth revolves around Sun due to gravitational attraction.

  19. Artificial satellites remain in orbit due to gravity.

  20. Escape velocity helps objects overcome Earth's gravity.

Newton's Law of Gravitation

  1. Every particle attracts every other particle.

  2. Force is directly proportional to product of masses.

  3. Force is inversely proportional to square of distance.

  4. Gravitational force is mutual.

  5. Action and reaction forces are equal.

  6. Gravitational force acts even in vacuum.

  7. It is independent of the medium.

  8. Doubling distance makes force one-fourth.

  9. Tripling distance makes force one-ninth.

  10. Doubling one mass doubles force.

  11. Doubling both masses makes force four times.

Gravitational Constant (G)

  1. Symbol = G.

  2. Universal Gravitational Constant.

  3. SI unit = Nm²/kg².

  4. SI value = 6.67 × 10⁻¹¹ Nm²/kg².

  5. G is constant throughout the universe.

  6. G does not depend upon location.

  7. G was measured by Henry Cavendish.

  8. G is a universal constant.

  9. G differs from acceleration due to gravity (g).

Acceleration due to Gravity (g)

  1. Symbol = g.

  2. Average value = 9.8 m/s².

  3. Near poles g is maximum.

  4. Near equator g is minimum.

  5. g decreases with altitude.

  6. g decreases with depth.

  7. On Moon g = 1.63 m/s².

  8. Moon's gravity is one-sixth of Earth's.

  9. Free-falling bodies accelerate with g.

  10. g is independent of mass.

Free Fall

  1. Motion under gravity alone is free fall.

  2. Air resistance neglected in free fall.

  3. All bodies fall with same acceleration.

  4. Galileo proved this concept.

  5. Feather falls slower due to air resistance.

  6. In vacuum feather and stone fall together.

Mass and Weight

  1. Mass is quantity of matter.

  2. SI unit of mass = kilogram.

  3. Weight is gravitational force.

  4. SI unit of weight = Newton.

  5. Mass remains constant.

  6. Weight changes from place to place.

  7. Mass is scalar quantity.

  8. Weight is vector quantity.

  9. Weight on Moon is one-sixth.

  10. Mass on Moon remains same.

  11. Spring balance measures weight.

  12. Beam balance measures mass.

Thrust and Pressure

  1. Thrust acts perpendicular to surface.

  2. Pressure = Thrust/Area.

  3. SI unit of pressure = Pascal.

  4. 1 Pascal = 1 N/m².

  5. Smaller area produces greater pressure.

  6. Sharp knife has small area.

  7. Nails have pointed ends.

  8. Snow shoes increase area.

  9. Camels have broad feet.

Buoyancy

  1. Upward force by liquid is buoyancy.

  2. Buoyant force acts upward.

  3. Buoyancy depends upon density.

  4. Buoyancy depends upon displaced liquid.

  5. Buoyancy causes floating.

  6. Ships float due to buoyancy.

  7. Ice floats on water.

Archimedes' Principle

  1. Proposed by Archimedes.

  2. Upward thrust equals weight of displaced liquid.

  3. Used in ships.

  4. Used in submarines.

  5. Used in hydrometers.

  6. Used to determine purity of metals.

Relative Density

  1. Relative density has no unit.

  2. It is a ratio.

  3. Water has relative density 1.

  4. Ice has relative density less than 1.

  5. Iron has relative density more than 1.

  6. Relative density = Density of substance/Density of water.

Floatation

  1. Floating body displaces liquid equal to its weight.

  2. Density less than water → floats.

  3. Density greater than water → sinks.

  4. Life jackets decrease average density.

  5. Hollow ships float due to lower average density.

  6. Dead Sea has high salt concentration.

  7. Floating is easier in Dead Sea.

IMPORTANT FORMULAS

QuantityFormula
Gravitational ForceF = Gm₁m₂/r²
WeightW = mg
PressureP = F/A
Densityρ = Mass/Volume
Relative DensityDensity of substance / Density of water
Free Fall Distances = ½gt²
Final Velocityv = u + gt
Velocity Relationv² = u² + 2gs
Escape Velocity11.2 km/s
Orbital Velocity7.9 km/s

IMPORTANT VALUES

QuantityValue
G6.67 × 10⁻¹¹ Nm²/kg²
g9.8 m/s²
Escape Velocity11.2 km/s
Orbital Velocity7.9 km/s
Moon Gravity1.63 m/s²
1 Pascal1 N/m²

PREVIOUS YEAR EXAM CONCEPTS

✔ Difference between Mass and Weight

✔ SI Unit of Pressure

✔ SI Unit of G

✔ Scientist who discovered gravitation

✔ Scientist who measured G

✔ Moon gravity

✔ Escape velocity

✔ Why ships float?

✔ Why nails are pointed?

✔ Why camels walk easily in deserts?

✔ Why ice floats?

✔ Why astronauts feel weightlessness?

✔ Why satellites do not fall?

✔ Which quantity remains constant on Moon?

VERY IMPORTANT FACTS

Gravity is the weakest force but has infinite range.

Weight becomes zero in free fall.
Mass never becomes zero.
Beam balance measures mass.
Spring balance measures weight.
Feather and stone fall together only in vacuum.
Pressure increases when area decreases.
Density of ice is less than water.
Sea water provides greater buoyant force.
Astronauts experience apparent weightlessness due to continuous free fall.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements about gravitation:

  1. Every object attracts every other object.

  2. Gravity is always repulsive.

  3. Force decreases with square of distance.

  4. Gravity acts only on planets.

A. 1 and 3 only
B. 2 and 4 only
C. 1, 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q2. Which of the following statements are correct?

  1. Mass is constant everywhere.

  2. Weight depends upon gravity.

  3. Weight is measured in kilogram.

  4. Beam balance measures mass.

A. 1, 2 and 4 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, 3 and 4

Answer: A

Q3. Regarding acceleration due to gravity (g):

  1. It is maximum at poles.

  2. It is minimum at equator.

  3. It increases with altitude.

  4. It decreases with depth.

A. 1, 2 and 4 only
B. 2 and 3 only
C. 1 and 3 only
D. All are correct

Answer: A

Q4. Which statements about buoyancy are correct?

  1. It acts upward.

  2. It depends upon density of liquid.

  3. It causes floating.

  4. It acts downward.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q5. Which of the following are applications of Archimedes' Principle?

  1. Hydrometer

  2. Ships

  3. Submarines

  4. Thermometer

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

PRACTICE MCQs

1. Who proposed the Universal Law of Gravitation?
A. Galileo
B. Newton
C. Einstein
D. Kepler
Answer: B

2. SI unit of gravitational constant is:
A. N/kg
B. Nm²/kg²
C. kg/m²
D. Joule
Answer: B

3. Weight is equal to:
A. m/g
B. mg
C. g/m
D. m²g
Answer: B

4. Moon's gravity is approximately:
A. One-half of Earth
B. One-third of Earth
C. One-sixth of Earth
D. One-tenth of Earth
Answer: C

5. Which instrument measures weight?
A. Beam balance
B. Spring balance
C. Hydrometer
D. Barometer
Answer: B

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Newton → Universal Gravitation
Cavendish → Measured G
G = 6.67 × 10⁻¹¹ Nm²/kg²
g = 9.8 m/s²
Weight = mg
Pressure = Force/Area
1 Pa = 1 N/m²
Mass constant; weight changes
Beam balance → Mass
Spring balance → Weight
Moon gravity = 1/6 of Earth
Escape velocity = 11.2 km/s
Orbital velocity = 7.9 km/s
Archimedes → Upthrust = Weight of displaced liquid
Density < Water → Floats

Gravity is always attractive and follows the inverse-square law.

CHAPTER 2 : HEAT (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

Heat and Temperature
Thermometer
Modes of Heat Transfer
Expansion of Solids, Liquids and Gases
Specific Heat Capacity
Change of State
Latent Heat
Celsius, Fahrenheit and Kelvin Scales
Conductors and Insulators
Sea Breeze and Land Breeze

Greenhouse Effect (Heat Concept)

QUICK REVISION (100+ One-Liner Points)

Basic Concepts

  1. Heat is a form of energy.

  2. SI unit of heat is Joule (J).

  3. Old unit of heat is calorie.

  4. 1 calorie = 4.186 Joules.

  5. Heat always flows from higher temperature to lower temperature.

  6. Temperature measures degree of hotness or coldness.

  7. SI unit of temperature is Kelvin (K).

  8. Temperature is measured using a thermometer.

  9. Heat is measured using a calorimeter.

  10. Heat is transferred due to temperature difference.

Heat and Temperature

  1. Heat is energy.

  2. Temperature is not energy.

  3. Heat depends upon mass.

  4. Temperature does not depend upon mass.

  5. Heat is an extensive property.

  6. Temperature is an intensive property.

  7. Two bodies at same temperature are in thermal equilibrium.

  8. No heat flows in thermal equilibrium.

  9. Human body temperature = 37°C.

  10. Human body temperature = 98.6°F.

Thermometers

  1. Clinical thermometer measures body temperature.

  2. Laboratory thermometer measures temperature of substances.

  3. Digital thermometer uses electronic sensors.

  4. Mercury expands uniformly.

  5. Mercury is a good conductor of heat.

  6. Alcohol thermometer is used in colder regions.

  7. Alcohol freezes at much lower temperature.

  8. Clinical thermometer range = 35°C–42°C.

  9. Laboratory thermometer range = –10°C to 110°C.

  10. Maximum-minimum thermometer records daily temperature.

Temperature Scales

  1. Celsius scale uses 0°C and 100°C.

  2. Fahrenheit scale uses 32°F and 212°F.

  3. Kelvin scale starts at absolute zero.

  4. 0 K = –273°C.

  5. Absolute zero is the lowest possible temperature.

  6. Kelvin has no degree symbol (K).

  7. Water freezes at 0°C.

  8. Water boils at 100°C.

  9. Water freezes at 32°F.

  10. Water boils at 212°F.

Modes of Heat Transfer

Conduction

  1. Heat transfer without movement of particles.

  2. Occurs mainly in solids.

  3. Metals are good conductors.

  4. Copper is a very good conductor.

  5. Silver is the best conductor.

  6. Wood is a poor conductor.

  7. Plastic is an insulator.

  8. Air is a poor conductor.

  9. Wool traps air.

  10. Thermos flask reduces conduction.

Convection

  1. Heat transfer through movement of liquids or gases.

  2. Occurs in fluids.

  3. Warm air rises.

  4. Cold air sinks.

  5. Sea breeze occurs during daytime.

  6. Land breeze occurs during nighttime.

  7. Chimneys work on convection.

  8. Ventilators work on convection.

  9. Hot air balloons rise due to convection.

  10. Ocean currents are due to convection.

Radiation

  1. Heat transfer without any medium.

  2. Sun's heat reaches Earth by radiation.

  3. Radiation travels in vacuum.

  4. Dark surfaces absorb more heat.

  5. Black body is the best absorber.

  6. Black body is the best emitter.

  7. White surfaces reflect heat.

  8. Polished surfaces are poor absorbers.

  9. Thermos flask minimizes radiation.

  10. Solar cooker works by radiation.

Expansion

  1. Most substances expand on heating.

  2. Expansion is maximum in gases.

  3. Expansion is least in solids.

  4. Railway tracks have expansion gaps.

  5. Bridges have expansion joints.

  6. Electric wires sag in summer.

  7. Bimetallic strip works on unequal expansion.

  8. Liquids also expand on heating.

  9. Gases expand rapidly.

  10. Water shows anomalous expansion.

Anomalous Expansion of Water

  1. Water is densest at 4°C.

  2. Water expands from 4°C to 0°C.

  3. Ice is lighter than water.

  4. Ice floats on water.

  5. Aquatic life survives in winter because of this property.

  6. Lakes freeze only at the surface.

Change of State

  1. Melting: Solid → Liquid.

  2. Freezing: Liquid → Solid.

  3. Vaporization: Liquid → Gas.

  4. Condensation: Gas → Liquid.

  5. Sublimation: Solid → Gas directly.

  6. Deposition: Gas → Solid directly.

  7. Melting point of ice = 0°C.

  8. Boiling point of water = 100°C.

  9. Heat absorbed during melting is latent heat.

  10. Heat absorbed during boiling is latent heat.

Latent Heat

  1. Temperature remains constant during change of state.

  2. Latent heat means hidden heat.

  3. Ice absorbs latent heat while melting.

  4. Steam contains latent heat.

  5. Steam causes severe burns because of latent heat.

  6. Condensation releases latent heat.

Specific Heat Capacity

  1. Water has high specific heat capacity.

  2. Sand has lower specific heat than water.

  3. Coastal areas have moderate climate.

  4. Desert regions experience extreme temperatures.

  5. Water is used as coolant in industries.

  6. Water is used in automobile radiators.

IMPORTANT FORMULAS

QuantityFormula
HeatQ = mcΔT
Specific Heatc = Q/mΔT
Celsius to KelvinK = °C + 273
Kelvin to Celsius°C = K − 273
Celsius to Fahrenheit°F = (9/5 × °C) + 32
Fahrenheit to Celsius°C = (°F − 32) × 5/9
Latent HeatQ = mL

IMPORTANT VALUES

QuantityValue
SI unit of HeatJoule
Old UnitCalorie
1 calorie4.186 J
Body Temperature37°C
Freezing Point of Water0°C
Boiling Point of Water100°C
Absolute Zero0 K (−273°C)
Density of Water Maximum4°C

PREVIOUS YEAR EXAM CONCEPTS

✔ SI unit of heat

✔ Difference between heat and temperature

✔ Clinical thermometer range

✔ Laboratory thermometer range

✔ Sea breeze and land breeze

✔ Conduction, convection and radiation

✔ Why woollen clothes keep us warm?

✔ Why cooking utensils are made of metals?

✔ Why handles are made of wood or plastic?

✔ Why black clothes are worn in winter?

✔ Why white clothes are worn in summer?

✔ Why ice floats?

✔ Why railway tracks have gaps?

✔ Why steam causes more burns than boiling water?

✔ Why desert cools rapidly at night?

VERY IMPORTANT FACTS

Heat always flows from hot body to cold body.
Silver is the best conductor of heat.
Air is a poor conductor.
Vacuum does not allow conduction or convection.
Radiation does not require a medium.
Water has the highest specific heat among common liquids.
Water is densest at 4°C.
Steam contains latent heat, so it causes more severe burns.
Black surfaces absorb and emit maximum heat.

White and polished surfaces reflect most heat.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Heat is a form of energy.

  2. Temperature is measured in Kelvin.

  3. Heat flows from cold body to hot body.

  4. Heat is measured in Joules.

A. 1, 2 and 4 only
B. 2 and 3 only
C. 1 and 3 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct regarding heat transfer?

  1. Conduction occurs mainly in solids.

  2. Convection occurs in liquids and gases.

  3. Radiation requires a material medium.

  4. Sun's heat reaches Earth by radiation.

A. 1, 2 and 4 only
B. 1 and 3 only
C. 2 and 3 only
D. All are correct

Answer: A

Q3. Which statements about water are correct?

  1. Water has maximum density at 4°C.

  2. Ice is denser than water.

  3. Ice floats on water.

  4. Lakes freeze from the top.

A. 1, 3 and 4 only
B. 2 and 4 only
C. 1 and 2 only
D. All are correct

Answer: A

Q4. Which of the following statements are correct?

  1. Black surfaces absorb more heat.

  2. White surfaces reflect most heat.

  3. Polished surfaces are good absorbers.

  4. Wool is a poor conductor of heat.

A. 1, 2 and 4 only
B. 1 and 3 only
C. 2 and 3 only
D. All are correct

Answer: A

Q5. During a change of state:

  1. Temperature remains constant.

  2. Latent heat is involved.

  3. Melting occurs at the melting point.

  4. Boiling occurs only above 150°C.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

PRACTICE MCQs

1. SI unit of heat is:
A. Watt
B. Joule
C. Newton
D. Pascal
Answer: B

2. Which mode of heat transfer does not require a medium?
A. Conduction
B. Convection
C. Radiation
D. Diffusion
Answer: C

3. Which metal is the best conductor of heat?
A. Copper
B. Iron
C. Silver
D. Aluminium
Answer: C

4. Maximum density of water occurs at:
A. 0°C
B. 2°C
C. 4°C
D. 10°C
Answer: C

5. Steam causes more severe burns than boiling water because it:
A. Has lower temperature
B. Contains latent heat of vaporization
C. Is lighter than air
D. Has lower specific heat capacity
Answer: B

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Heat → Energy (SI unit: Joule)
Temperature → Degree of hotness (SI unit: Kelvin)
Q = mcΔT
Q = mL (Latent heat)
Conduction → Solids

Convection → Liquids & Gases

Radiation → No medium required
Sun → Radiation
Silver → Best conductor
Air/Wood/Wool → Poor conductors (insulators)
Water maximum density → 4°C
Ice floats because its density is less than that of water.
Black surfaces → Best absorbers and emitters
White/polished surfaces → Best reflectors
Sea breeze → Day; Land breeze → Night

Steam burns more than boiling water because it releases latent heat during condensation.

CHAPTER 3 : LIGHT (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

  • Nature of Light

  • Reflection of Light

  • Laws of Reflection

  • Plane and Spherical Mirrors

  • Image Formation

  • Refraction of Light

  • Lenses

  • Human Eye

  • Defects of Vision

  • Dispersion and Spectrum

  • Scattering of Light

  • Rainbow

  • Optical Instruments

QUICK REVISION (100+ One-Liner Points)

Basic Concepts

  1. Light is a form of energy.

  2. Light enables us to see objects.

  3. Light travels in a straight line.

  4. Light is an electromagnetic wave.

  5. Light does not require a material medium.

  6. Speed of light in vacuum = 3 × 10⁸ m/s.

  7. Vacuum is the fastest medium for light.

  8. Light slows down in glass and water.

  9. Luminous objects emit their own light.

  10. Non-luminous objects reflect light.

Reflection of Light

  1. Reflection is the bouncing back of light.

  2. Reflection occurs from polished surfaces.

  3. Angle of incidence equals angle of reflection.

  4. Incident ray, reflected ray and normal lie in the same plane.

  5. Reflection follows two laws.

  6. Plane mirror forms a virtual image.

  7. Plane mirror forms an erect image.

  8. Image in plane mirror is laterally inverted.

  9. Image distance equals object distance.

  10. Image size equals object size.

Plane Mirror

  1. Mirror writing is due to lateral inversion.

  2. Periscope uses plane mirrors.

  3. Kaleidoscope uses multiple mirrors.

  4. Number of images depends upon angle between mirrors.

  5. Image cannot be obtained on a screen.

Spherical Mirrors

  1. Two types: Concave and Convex.

  2. Concave mirror is a converging mirror.

  3. Convex mirror is a diverging mirror.

  4. Concave mirror can produce real images.

  5. Convex mirror always produces virtual images.

  6. Concave mirror is used in shaving mirrors.

  7. Dentist uses concave mirror.

  8. Solar furnace uses concave mirror.

  9. Headlights use concave mirror.

  10. Convex mirrors are used as rear-view mirrors.

  11. Convex mirrors provide a wider field of view.

  12. Pole is the center of mirror surface.

  13. Principal axis passes through pole and center of curvature.

  14. Radius of curvature = 2 × focal length.

  15. Focus lies midway between pole and center.

Mirror Formula

  1. Mirror formula: 1/f = 1/v + 1/u

  2. Magnification = Image height/Object height.

  3. Magnification = –v/u.

  4. Convex mirror has positive focal length.

  5. Concave mirror has negative focal length (Cartesian sign convention).

Refraction

  1. Refraction is bending of light.

  2. Refraction occurs due to change in speed.

  3. Light bends towards the normal in a denser medium.

  4. Light bends away from the normal in a rarer medium.

  5. Speed decreases in denser medium.

  6. Speed increases in rarer medium.

  7. Refraction explains the apparent depth of water.

  8. Coin appears raised due to refraction.

  9. Fish appears nearer to the surface.

  10. Twinkling of stars is due to atmospheric refraction.

Refractive Index

  1. Symbol = n.

  2. Vacuum has refractive index = 1.

  3. Glass has higher refractive index than water.

  4. Higher refractive index means lower speed of light.

  5. Diamond has a very high refractive index.

Lenses

  1. Convex lens is a converging lens.

  2. Concave lens is a diverging lens.

  3. Convex lens can produce real images.

  4. Concave lens always forms virtual images.

  5. Convex lens is thicker at the center.

  6. Concave lens is thinner at the center.

  7. Camera uses a convex lens.

  8. Microscope uses convex lenses.

  9. Telescope uses convex lenses.

  10. Magnifying glass is a convex lens.

  11. Spectacles for hypermetropia use convex lenses.

  12. Spectacles for myopia use concave lenses.

Lens Formula

  1. Lens formula: 1/f = 1/v − 1/u

  2. Power = 1/f (in metres).

  3. SI unit of power = Dioptre.

  4. Convex lens has positive power.

  5. Concave lens has negative power.

Human Eye

  1. Retina is the light-sensitive part.

  2. Iris controls the amount of light.

  3. Pupil regulates light entry.

  4. Cornea is the transparent front layer.

  5. Eye lens is convex.

  6. Optic nerve carries impulses to the brain.

  7. Image is formed on the retina.

  8. Normal least distance of distinct vision = 25 cm.

  9. Persistence of vision ≈ 1/16 second.

Defects of Vision

  1. Myopia = Short-sightedness.

  2. Myopia corrected by a concave lens.

  3. Hypermetropia = Long-sightedness.

  4. Hypermetropia corrected by a convex lens.

  5. Presbyopia occurs in old age.

  6. Cataract causes clouding of the eye lens.

  7. Astigmatism is due to irregular curvature of the cornea.

Dispersion

  1. Dispersion is splitting of white light.

  2. Prism disperses white light.

  3. VIBGYOR has seven colours.

  4. Violet deviates the most.

  5. Red deviates the least.

  6. Rainbow is formed by refraction, dispersion and total internal reflection.

  7. Primary rainbow shows Red outside and Violet inside.

Scattering

  1. Blue colour of the sky is due to scattering.

  2. Red colour at sunrise and sunset is due to scattering.

  3. Tyndall effect is scattering by colloidal particles.

  4. Red has the longest wavelength.

  5. Violet has the shortest wavelength.

IMPORTANT FORMULAS

QuantityFormula
Speed of Light3 × 10⁸ m/s
Mirror Formula1/f = 1/v + 1/u
Lens Formula1/f = 1/v − 1/u
Magnification (Mirror)m = −v/u
Magnification (Lens)m = v/u
Radius of CurvatureR = 2f
Power of LensP = 1/f (metre)

IMPORTANT VALUES

QuantityValue
Speed of Light3 × 10⁸ m/s
Least Distance of Distinct Vision25 cm
Persistence of Vision1/16 s
Refractive Index of Vacuum1
Colours in Spectrum7 (VIBGYOR)

PREVIOUS YEAR EXAM CONCEPTS

✔ Laws of reflection

✔ Image formed by a plane mirror

✔ Uses of concave and convex mirrors

✔ Rear-view mirror

✔ Dentist's mirror

✔ Refraction in water

✔ Why stars twinkle?

✔ Why sky appears blue?

✔ Why sunsets appear red?

✔ Defects of vision and corrective lenses

✔ Least distance of distinct vision

✔ Power of lens

✔ Dispersion through a prism

✔ Rainbow formation

✔ Tyndall effect

VERY IMPORTANT FACTS

  • Light travels fastest in a vacuum.

  • Angle of incidence = Angle of reflection.

  • Plane mirror forms a virtual, erect, same-sized image.

  • Convex mirror always gives a virtual, erect and diminished image.

  • Concave mirror is used in headlights, shaving mirrors and solar cookers.

  • Convex mirrors are preferred for rear-view mirrors because they provide a wide field of view.

  • Myopia is corrected by a concave lens.

  • Hypermetropia is corrected by a convex lens.

  • Violet light has the maximum deviation, red the minimum.

  • Blue light scatters more than red light.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Light travels in a straight line.

  2. Light requires a material medium for propagation.

  3. Speed of light in vacuum is about 3 × 10⁸ m/s.

  4. Light is an electromagnetic wave.

A. 1, 3 and 4 only
B. 1 and 2 only
C. 2 and 3 only
D. All are correct

Answer: A

Q2. Which of the following statements about mirrors are correct?

  1. A plane mirror forms a virtual image.

  2. A convex mirror always forms a diminished image.

  3. A concave mirror is used as a shaving mirror.

  4. A convex mirror is used in solar furnaces.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q3. Which statements about refraction are correct?

  1. Refraction occurs due to change in the speed of light.

  2. Light bends towards the normal on entering a denser medium.

  3. Stars twinkle due to atmospheric refraction.

  4. Refraction does not occur in transparent media.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q4. Which of the following statements are correct?

  1. Myopia is corrected using a concave lens.

  2. Hypermetropia is corrected using a convex lens.

  3. Cataract is caused by clouding of the eye lens.

  4. Astigmatism results from irregular curvature of the cornea.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Consider the following statements:

  1. Blue colour of the sky is due to scattering of light.

  2. Rainbow is formed due to dispersion, refraction and total internal reflection.

  3. Violet light deviates more than red light in a prism.

  4. Red light has the shortest wavelength.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

PRACTICE MCQs

1. Which mirror is used as a rear-view mirror in vehicles?
A. Plane mirror
B. Concave mirror
C. Convex mirror
D. Parabolic mirror
Answer: C

2. The least distance of distinct vision for a normal human eye is:
A. 10 cm
B. 15 cm
C. 25 cm
D. 50 cm
Answer: C

3. Which lens is used to correct myopia?
A. Convex lens
B. Concave lens
C. Cylindrical lens
D. Bifocal lens
Answer: B

4. Which colour deviates the most in a glass prism?
A. Red
B. Yellow
C. Green
D. Violet
Answer: D

5. The blue colour of the sky is mainly due to:
A. Reflection
B. Refraction
C. Scattering of light
D. Diffraction
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Speed of light = 3 × 10⁸ m/s
Reflection: ∠i = ∠r
Plane mirror → Virtual, erect, same size, laterally inverted
Concave mirror → Converging
Convex mirror → Diverging, rear-view mirror
Mirror formula: 1/f = 1/v + 1/u
Lens formula: 1/f = 1/v − 1/u
Power of lens = 1/f (Dioptre)
Myopia → Concave lens
Hypermetropia → Convex lens
Retina → Image formation
Least distance of distinct vision = 25 cm
Blue sky → Scattering
Red sunset → Scattering of shorter wavelengths
Rainbow → Refraction + Dispersion + Total Internal Reflection

VIBGYOR: Violet deviates most, Red deviates least.

CHAPTER 4 : MATTER (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

  • Matter and its Properties

  • States of Matter

  • Physical and Chemical Changes

  • Diffusion

  • Evaporation

  • Sublimation

  • Melting and Boiling

  • Plasma and Bose-Einstein Condensate (BEC)

  • Pure Substances and Mixtures

  • Elements, Compounds and Mixtures

  • Separation Techniques

QUICK REVISION (100+ One-Liner Points)

Matter

  1. Matter is anything that has mass and occupies space.

  2. Matter is made up of tiny particles.

  3. Matter has inertia.

  4. Particles of matter are continuously moving.

  5. Particles of matter attract one another.

  6. Matter exists in five states.

  7. States are Solid, Liquid, Gas, Plasma and Bose-Einstein Condensate (BEC).

  8. Kinetic energy of particles increases with temperature.

  9. Intermolecular force is strongest in solids.

  10. Intermolecular force is weakest in gases.

Properties of Particles

  1. Matter is made of atoms and molecules.

  2. Particles have spaces between them.

  3. Particles are always in motion.

  4. Heating increases particle movement.

  5. Cooling decreases particle movement.

  6. Diffusion proves movement of particles.

  7. Brownian movement supports kinetic theory.

  8. Matter has both mass and volume.

  9. Density differs for different substances.

  10. Compressibility is maximum in gases.

Solids

  1. Solids have definite shape.

  2. Solids have definite volume.

  3. Solids are rigid.

  4. Particles are closely packed.

  5. Intermolecular force is maximum.

  6. Kinetic energy is minimum.

  7. Solids are almost incompressible.

  8. Diffusion is very slow.

  9. Ice is a solid form of water.

  10. Iron is a solid at room temperature.

Liquids

  1. Liquids have definite volume.

  2. Liquids have no definite shape.

  3. Liquids take the shape of the container.

  4. Liquids flow easily.

  5. Liquids are slightly compressible.

  6. Diffusion is faster than in solids.

  7. Water is the universal solvent.

  8. Mercury is the only liquid metal at room temperature.

  9. Bromine is the only liquid non-metal.

  10. Surface tension is a property of liquids.

Gases

  1. Gases have no definite shape.

  2. Gases have no definite volume.

  3. Gases are highly compressible.

  4. Gases diffuse very rapidly.

  5. Particles move randomly.

  6. Intermolecular force is minimum.

  7. Kinetic energy is maximum.

  8. LPG is stored under pressure.

  9. CNG is used as automobile fuel.

  10. Air is a mixture of gases.

Plasma

  1. Plasma is the fourth state of matter.

  2. Plasma contains charged particles.

  3. Plasma conducts electricity.

  4. Sun consists mainly of plasma.

  5. Lightning contains plasma.

  6. Fluorescent lamps contain plasma.

  7. Neon signs work due to plasma.

  8. Plasma is produced at very high temperatures.

Bose-Einstein Condensate (BEC)

  1. BEC is the fifth state of matter.

  2. It is formed near absolute zero.

  3. Predicted by Satyendra Nath Bose and Albert Einstein.

  4. Atoms behave as one particle in BEC.

  5. BEC has extremely low kinetic energy.

Change of State

  1. Melting: Solid → Liquid.

  2. Freezing: Liquid → Solid.

  3. Vaporization: Liquid → Gas.

  4. Condensation: Gas → Liquid.

  5. Sublimation: Solid → Gas.

  6. Deposition: Gas → Solid.

  7. Melting absorbs heat.

  8. Freezing releases heat.

  9. Condensation releases heat.

  10. Vaporization absorbs heat.

Evaporation

  1. Evaporation occurs at all temperatures.

  2. Boiling occurs only at the boiling point.

  3. Evaporation causes cooling.

  4. Sweating cools the body.

  5. Desert coolers work on evaporation.

  6. Wet clothes dry by evaporation.

  7. Rate of evaporation increases with temperature.

  8. Wind speed increases evaporation.

  9. Larger surface area increases evaporation.

  10. Lower humidity increases evaporation.

Diffusion

  1. Diffusion is the mixing of particles.

  2. Diffusion is fastest in gases.

  3. Diffusion is slowest in solids.

  4. Higher temperature increases diffusion.

  5. Smell of perfume spreads due to diffusion.

  6. Incense sticks spread fragrance by diffusion.

Pure Substances

  1. Pure substances have fixed composition.

  2. Elements are pure substances.

  3. Compounds are pure substances.

  4. Gold (24 carat) is a pure substance.

  5. Distilled water is a pure substance.

Elements

  1. Element contains only one type of atom.

  2. Elements cannot be broken chemically.

  3. Hydrogen is the lightest element.

  4. Helium is an inert gas.

  5. Oxygen supports combustion.

  6. Nitrogen is the most abundant gas in air.

  7. Carbon exists in different allotropes.

  8. Diamond is the hardest natural substance.

Compounds

  1. Compounds are formed by chemical combination.

  2. Water (H₂O) is a compound.

  3. Carbon dioxide (CO₂) is a compound.

  4. Sodium chloride (NaCl) is common salt.

  5. Properties of compounds differ from constituent elements.

Mixtures

  1. Mixtures have variable composition.

  2. Components retain their properties.

  3. Air is a homogeneous mixture.

  4. Brass is an alloy of copper and zinc.

  5. Steel is an alloy of iron and carbon.

  6. Milk is a colloid.

  7. Smoke is a colloid.

  8. Fog is an aerosol.

Separation Techniques

  1. Filtration separates insoluble solids from liquids.

  2. Evaporation separates dissolved solids.

  3. Distillation separates liquids with different boiling points.

  4. Fractional distillation separates petroleum products.

  5. Chromatography separates coloured substances.

  6. Magnetic separation separates magnetic materials.

  7. Centrifugation separates cream from milk.

  8. Sublimation separates camphor or ammonium chloride.

IMPORTANT FORMULAS

QuantityFormula
DensityDensity = Mass / Volume (ρ = m/V)
Percentage Composition(Mass of Component / Total Mass) × 100

IMPORTANT VALUES

QuantityValue
Absolute Zero0 K = –273°C
Boiling Point of Water100°C
Melting Point of Ice0°C
Most Abundant Gas in AirNitrogen (78%)
Oxygen in Air21%
Argon in Air0.93%
Carbon Dioxide in Air0.04%

PREVIOUS YEAR EXAM CONCEPTS

✔ Definition of matter

✔ Properties of particles of matter

✔ States of matter

✔ Plasma and BEC

✔ Difference between evaporation and boiling

✔ Diffusion examples

✔ Physical vs chemical change

✔ Element, compound and mixture

✔ Homogeneous and heterogeneous mixtures

✔ Separation techniques

✔ Mercury and bromine as liquid elements

✔ Alloys and their composition

✔ Air composition

✔ Water as the universal solvent

VERY IMPORTANT FACTS

  • Matter has mass and occupies space.

  • Solids have maximum intermolecular force.

  • Gases have maximum kinetic energy.

  • Mercury is the only liquid metal at room temperature.

  • Bromine is the only liquid non-metal at room temperature.

  • Plasma is found in the Sun and stars.

  • BEC is formed near absolute zero.

  • Evaporation causes cooling.

  • Air is a homogeneous mixture.

  • Water is called the universal solvent.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Matter has mass and occupies space.

  2. Matter is made up of tiny particles.

  3. Particles of matter are always at rest.

  4. Particles of matter attract each other.

A. 1, 2 and 4 only
B. 2 and 3 only
C. 1 and 3 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct?

  1. Solids have a definite shape.

  2. Liquids have a definite volume.

  3. Gases are highly compressible.

  4. Solids have maximum kinetic energy.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q3. Which statements regarding evaporation are correct?

  1. It occurs at all temperatures.

  2. It causes cooling.

  3. It is faster at higher temperatures.

  4. It decreases with increasing wind speed.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q4. Which of the following are pure substances?

  1. Oxygen

  2. Water

  3. Air

  4. Sodium chloride

A. 1, 2 and 4 only
B. 1 and 3 only
C. 2 and 3 only
D. All are correct

Answer: A

Q5. Which of the following separation methods are correctly matched?

  1. Filtration – Insoluble solid from liquid

  2. Distillation – Liquids with different boiling points

  3. Chromatography – Separation of coloured components

  4. Magnetic separation – Non-magnetic substances only

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

PRACTICE MCQs

1. Which state of matter has the highest compressibility?
A. Solid
B. Liquid
C. Gas
D. Plasma
Answer: C

2. The only liquid metal at room temperature is:
A. Sodium
B. Mercury
C. Gallium
D. Lead
Answer: B

3. Which process causes cooling?
A. Freezing
B. Condensation
C. Evaporation
D. Sublimation
Answer: C

4. Air is a:
A. Compound
B. Element
C. Homogeneous mixture
D. Heterogeneous mixture
Answer: C

5. Which technique is used to separate cream from milk?
A. Filtration
B. Distillation
C. Centrifugation
D. Sublimation
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Matter = Mass + Occupies Space
States: Solid, Liquid, Gas, Plasma, BEC
Solids → Maximum intermolecular force
Gases → Maximum kinetic energy and compressibility
Mercury → Liquid metal
Bromine → Liquid non-metal
Plasma → Sun, stars, lightning
BEC → Near 0 K
Evaporation → Cooling, occurs at all temperatures
Diffusion → Fastest in gases
Water → Universal solvent
Air → Homogeneous mixture
Density = Mass/Volume
Nitrogen = 78% of air, Oxygen = 21%

Distillation → Liquids; Filtration → Insoluble solids; Chromatography → Colours; Centrifugation → Cream from milk

CHAPTER 5 : ACIDS, BASES AND SALTS (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

  • Acids, Bases and Salts

  • Indicators

  • pH Scale

  • Strength of Acids and Bases

  • Chemical Properties

  • Neutralization Reaction

  • Common Salts and Their Uses

  • Water of Crystallization

  • Everyday Applications

QUICK REVISION (120+ One-Liner Points)

Basic Concepts

  1. Acids are sour in taste.

  2. Bases are bitter in taste.

  3. Bases feel soapy to touch.

  4. Salts are formed by neutralization.

  5. Acids release H⁺ ions in aqueous solution.

  6. Bases release OH⁻ ions in aqueous solution.

  7. Acids conduct electricity in aqueous solution.

  8. Dry acids do not conduct electricity.

  9. Water is essential for ionization of acids.

  10. Acidic solutions have pH less than 7.

Acids

  1. Hydrochloric acid (HCl) is a strong acid.

  2. Sulphuric acid (H₂SO₄) is called the King of Chemicals.

  3. Nitric acid (HNO₃) is a strong oxidizing agent.

  4. Acetic acid is present in vinegar.

  5. Citric acid is present in lemon and orange.

  6. Tartaric acid is present in tamarind.

  7. Oxalic acid is present in tomato and spinach.

  8. Lactic acid is present in curd.

  9. Formic acid is present in ant sting.

  10. Ascorbic acid is Vitamin C.

  11. Carbonic acid is present in soft drinks.

  12. Acids react with metals to release hydrogen gas.

  13. Acids react with carbonates to release carbon dioxide.

  14. Acids react with bicarbonates to release carbon dioxide.

  15. Strong acids ionize completely in water.

Bases

  1. Sodium hydroxide (NaOH) is caustic soda.

  2. Potassium hydroxide (KOH) is caustic potash.

  3. Calcium hydroxide is slaked lime.

  4. Magnesium hydroxide is milk of magnesia.

  5. Ammonium hydroxide is a weak base.

  6. Bases turn red litmus blue.

  7. Alkalis are water-soluble bases.

  8. Strong bases ionize completely.

  9. Bases neutralize acids.

  10. Soap solution is basic.

Indicators

  1. Litmus is a natural indicator.

  2. Red litmus turns blue in a base.

  3. Blue litmus turns red in an acid.

  4. Phenolphthalein is colourless in acid.

  5. Phenolphthalein is pink in base.

  6. Methyl orange is red in acid.

  7. Methyl orange is yellow in base.

  8. China rose is a natural indicator.

  9. Turmeric turns reddish-brown in base.

  10. Turmeric remains yellow in acid.

pH Scale

  1. pH scale ranges from 0 to 14.

  2. pH 7 is neutral.

  3. pH below 7 is acidic.

  4. pH above 7 is basic.

  5. Lower pH means stronger acid.

  6. Higher pH means stronger base.

  7. Human blood pH ≈ 7.4.

  8. Pure water has pH 7.

  9. Gastric juice contains hydrochloric acid.

  10. Tooth decay begins below pH 5.5.

  11. Toothpaste is basic.

  12. Rainwater is slightly acidic.

  13. Acid rain has pH below 5.6.

Neutralization

  1. Acid + Base → Salt + Water.

  2. Neutralization is generally exothermic.

  3. HCl + NaOH → NaCl + H₂O.

  4. Antacids neutralize excess stomach acid.

  5. Lime neutralizes acidic soil.

  6. Organic manure neutralizes basic soil.

  7. Bee sting is acidic.

  8. Baking soda relieves bee sting irritation.

  9. Wasp sting is alkaline.

  10. Vinegar neutralizes wasp sting.

Salts

  1. Common salt = Sodium chloride (NaCl).

  2. Common salt is obtained from sea water.

  3. Rock salt is impure sodium chloride.

  4. Iodized salt prevents goitre.

  5. Sodium bicarbonate is baking soda.

  6. Baking soda formula = NaHCO₃.

  7. Baking powder contains baking soda and tartaric acid.

  8. Washing soda formula = Na₂CO₃·10H₂O.

  9. Washing soda softens hard water.

  10. Bleaching powder formula = CaOCl₂.

  11. Bleaching powder disinfects drinking water.

  12. Bleaching powder is used for bleaching cotton and paper.

  13. Plaster of Paris formula = CaSO₄·½H₂O.

  14. Gypsum formula = CaSO₄·2H₂O.

  15. POP is prepared by heating gypsum.

  16. POP is used for fractured bones.

  17. POP is used for statues and false ceilings.

Water of Crystallization

  1. Water molecules attached to salt crystals are called water of crystallization.

  2. Copper sulphate crystals are blue due to water of crystallization.

  3. Anhydrous copper sulphate is white.

  4. Washing soda contains 10 molecules of water.

  5. Gypsum contains 2 molecules of water.

Everyday Applications

  1. Vinegar is used in food preservation.

  2. Baking soda is used in baking.

  3. Baking soda is used in soda-acid fire extinguishers.

  4. Antacids reduce stomach acidity.

  5. Toothpaste is basic.

  6. Lime water turns milky with CO₂.

  7. Bleaching powder disinfects wells.

  8. Hydrochloric acid is present in the stomach.

  9. Sulphuric acid is used in car batteries.

  10. Nitric acid is used in fertilizers and explosives.

Chemical Reactions

  1. Acid + Metal → Salt + H₂.

  2. Acid + Carbonate → Salt + CO₂ + H₂O.

  3. Acid + Bicarbonate → Salt + CO₂ + H₂O.

  4. Acid + Base → Salt + Water.

  5. Base + Non-metal oxide → Salt + Water.

  6. Metal oxide + Acid → Salt + Water.

  7. Non-metal oxide + Base → Salt + Water.

  8. Carbon dioxide is an acidic oxide.

  9. Calcium oxide is a basic oxide.

  10. Amphoteric oxides react with both acids and bases.

  11. Zinc oxide is amphoteric.

  12. Aluminium oxide is amphoteric.

IMPORTANT FORMULAS

CompoundFormula
Hydrochloric AcidHCl
Sulphuric AcidH₂SO₄
Nitric AcidHNO₃
Acetic AcidCH₃COOH
Sodium HydroxideNaOH
Potassium HydroxideKOH
Calcium HydroxideCa(OH)₂
Baking SodaNaHCO₃
Washing SodaNa₂CO₃·10H₂O
Bleaching PowderCaOCl₂
Plaster of ParisCaSO₄·½H₂O
GypsumCaSO₄·2H₂O

IMPORTANT TABLE

SubstanceNatureImportant Use
Lemon JuiceAcidicContains citric acid
VinegarAcidicFood preservative
CurdAcidicContains lactic acid
SoapBasicCleaning
ToothpasteBasicPrevents tooth decay
Lime WaterBasicDetects CO₂
Common SaltNeutralFood seasoning

PREVIOUS YEAR EXAM CONCEPTS

✔ pH scale

✔ Indicators and colour changes

✔ Formula of baking soda

✔ Formula of washing soda

✔ Formula of bleaching powder

✔ Formula of POP

✔ Water of crystallization

✔ Neutralization reaction

✔ Tooth decay and pH

✔ Antacids

✔ Strong and weak acids

✔ Natural indicators

✔ Acids present in fruits

✔ Acid rain

✔ Everyday uses of salts

VERY IMPORTANT FACTS

  • pH = 7 → Neutral

  • pH < 7 → Acidic

  • pH > 7 → Basic

  • HCl is present in the stomach.

  • Tooth decay starts below pH 5.5.

  • Sulphuric acid is called the King of Chemicals.

  • NaHCO₃ = Baking soda.

  • Na₂CO₃·10H₂O = Washing soda.

  • CaOCl₂ = Bleaching powder.

  • CaSO₄·½H₂O = Plaster of Paris.

  • ZnO and Al₂O₃ are amphoteric oxides.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Acids release H⁺ ions in aqueous solution.

  2. Bases release OH⁻ ions in aqueous solution.

  3. Pure water has pH 7.

  4. Acids turn red litmus blue.

A. 1, 2 and 3 only
B. 1 and 4 only
C. 2 and 3 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct?

  1. Baking soda is NaHCO₃.

  2. Washing soda contains water of crystallization.

  3. Bleaching powder is CaOCl₂.

  4. Plaster of Paris is CaSO₄·2H₂O.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q3. Which of the following are natural indicators?

  1. Litmus

  2. Turmeric

  3. China rose

  4. Phenolphthalein

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q4. Which statements are correct regarding neutralization?

  1. Acid + Base → Salt + Water.

  2. Neutralization is generally exothermic.

  3. Antacids neutralize excess stomach acid.

  4. Lime is added to acidic soil.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Which statements are correct?

  1. Zinc oxide is amphoteric.

  2. Aluminium oxide is amphoteric.

  3. Carbon dioxide is an acidic oxide.

  4. Calcium oxide is a basic oxide.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

PRACTICE MCQs

1. Which acid is present in vinegar?
A. Citric acid
B. Acetic acid
C. Oxalic acid
D. Formic acid
Answer: B

2. Which indicator turns pink in a basic solution?
A. Litmus
B. Methyl orange
C. Phenolphthalein
D. Turmeric
Answer: C

3. The formula of bleaching powder is:
A. CaCO₃
B. CaOCl₂
C. CaSO₄
D. Ca(OH)₂
Answer: B

4. Tooth decay generally starts when the pH of the mouth falls below:
A. 7.0
B. 6.5
C. 5.5
D. 4.0
Answer: C

5. Which compound is used to make casts for fractured bones?
A. Gypsum
B. Baking soda
C. Plaster of Paris
D. Bleaching powder
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Acid → H⁺ ions
Base → OH⁻ ions
Salt = Acid + Base
pH < 7 → Acid
pH = 7 → Neutral
pH > 7 → Base
HCl → Stomach acid
H₂SO₄ → King of Chemicals
NaHCO₃ → Baking soda
Na₂CO₃·10H₂O → Washing soda
CaOCl₂ → Bleaching powder
CaSO₄·½H₂O → Plaster of Paris
Gypsum → CaSO₄·2H₂O
Tooth decay → pH below 5.5
ZnO and Al₂O₃ → Amphoteric oxides

Antacids neutralize excess stomach acid.

CHAPTER 6 : ELEMENTS, PERIODIC CLASSIFICATION AND PERIODIC TABLE (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

  • Elements and Symbols

  • Dobereiner's Triads

  • Newlands' Law of Octaves

  • Mendeleev's Periodic Table

  • Modern Periodic Table

  • Groups and Periods

  • Electronic Configuration

  • Trends in the Periodic Table

  • Metals, Non-metals and Metalloids

  • Important Families of Elements

QUICK REVISION (120+ One-Liner Points)

Basic Concepts

  1. An element is a pure substance made of one type of atom.

  2. Elements cannot be broken into simpler substances by chemical means.

  3. At present, 118 elements are officially recognized.

  4. The first element is Hydrogen.

  5. The last known element is Oganesson (Og).

  6. Hydrogen is the lightest element.

  7. Helium is the lightest noble gas.

  8. Uranium is the heaviest naturally occurring element.

  9. Elements are represented by symbols.

  10. Symbols are usually one or two letters.

Symbols of Important Elements

  1. Hydrogen → H

  2. Helium → He

  3. Lithium → Li

  4. Carbon → C

  5. Nitrogen → N

  6. Oxygen → O

  7. Sodium → Na

  8. Potassium → K

  9. Calcium → Ca

  10. Iron → Fe

  11. Copper → Cu

  12. Zinc → Zn

  13. Silver → Ag

  14. Gold → Au

  15. Mercury → Hg

  16. Lead → Pb

  17. Tin → Sn

  18. Chlorine → Cl

  19. Bromine → Br

  20. Iodine → I

Dobereiner's Triads

  1. Proposed by Johann Dobereiner.

  2. Elements were grouped in threes.

  3. Middle element had average atomic mass.

  4. Lithium, Sodium and Potassium form a triad.

  5. Calcium, Strontium and Barium form another triad.

  6. Triads could not classify all known elements.

Newlands' Law of Octaves

  1. Proposed by John Newlands.

  2. Every eighth element has similar properties.

  3. Worked well up to calcium.

  4. Failed for heavier elements.

  5. Noble gases were not known at that time.

Mendeleev's Periodic Table

  1. Proposed by Dmitri Mendeleev.

  2. Based on increasing atomic mass.

  3. Similar properties were grouped together.

  4. Mendeleev left gaps for undiscovered elements.

  5. He predicted properties of unknown elements.

  6. Eka-silicon was later discovered as germanium.

  7. Noble gases were added later.

  8. Position of hydrogen remained uncertain.

  9. Isotopes could not be explained.

Modern Periodic Table

  1. Proposed by Henry Moseley.

  2. Based on increasing atomic number.

  3. Modern Periodic Law depends on atomic number.

  4. There are 7 periods.

  5. There are 18 groups.

  6. Period indicates number of electron shells.

  7. Group indicates valence electrons (for main-group elements).

  8. Atomic number increases from left to right.

  9. Elements in the same group have similar chemical properties.

  10. Periodic table is divided into s, p, d and f blocks.

Groups

  1. Group 1 → Alkali metals.

  2. Group 2 → Alkaline earth metals.

  3. Groups 3–12 → Transition metals.

  4. Group 17 → Halogens.

  5. Group 18 → Noble gases.

  6. Alkali metals are highly reactive.

  7. Halogens are highly reactive non-metals.

  8. Noble gases are chemically inert.

  9. Helium has a duplet (2 electrons).

  10. Other noble gases have octets.

Periods

  1. First period contains 2 elements.

  2. Second period contains 8 elements.

  3. Third period contains 8 elements.

  4. Fourth period contains 18 elements.

  5. Fifth period contains 18 elements.

  6. Sixth period contains 32 elements.

  7. Seventh period is incomplete.

  8. Atomic size decreases across a period.

  9. Atomic size increases down a group.

  10. Metallic character decreases across a period.

Periodic Trends

  1. Atomic radius decreases from left to right.

  2. Atomic radius increases from top to bottom.

  3. Ionization energy increases across a period.

  4. Ionization energy decreases down a group.

  5. Electronegativity increases across a period.

  6. Electronegativity decreases down a group.

  7. Metallic character increases down a group.

  8. Non-metallic character increases across a period.

  9. Reactivity of alkali metals increases down the group.

  10. Reactivity of halogens decreases down the group.

Metals, Non-metals and Metalloids

  1. Metals are on the left side of the periodic table.

  2. Non-metals are on the right side.

  3. Metalloids lie between metals and non-metals.

  4. Silicon is a metalloid.

  5. Germanium is a metalloid.

  6. Boron is a metalloid.

  7. Arsenic is a metalloid.

  8. Antimony is a metalloid.

  9. Tellurium is a metalloid.

  10. Polonium is often classified as a metalloid.

Important Elements

  1. Hydrogen is the most abundant element in the universe.

  2. Oxygen is the most abundant element in Earth's crust.

  3. Nitrogen is the most abundant gas in the atmosphere.

  4. Iron is the most abundant transition metal in Earth's crust.

  5. Aluminium is the most abundant metal in Earth's crust.

  6. Carbon forms the largest number of compounds.

  7. Fluorine is the most electronegative element.

  8. Cesium is among the most electropositive stable elements.

  9. Tungsten has one of the highest melting points among pure metals.

  10. Mercury is liquid at room temperature.

Electronic Configuration

  1. Maximum electrons in K shell = 2.

  2. Maximum electrons in L shell = 8.

  3. Maximum electrons in M shell = 18.

  4. Valence electrons determine chemical properties.

  5. Noble gases have complete outermost shells.

  6. Sodium has one valence electron.

  7. Chlorine has seven valence electrons.

  8. Magnesium has two valence electrons.

  9. Neon has eight electrons in its outer shell.

  10. Argon has eight electrons in its outer shell.

IMPORTANT TABLES

First 20 Elements

Atomic No.ElementSymbol
1HydrogenH
2HeliumHe
3LithiumLi
4BerylliumBe
5BoronB
6CarbonC
7NitrogenN
8OxygenO
9FluorineF
10NeonNe
11SodiumNa
12MagnesiumMg
13AluminiumAl
14SiliconSi
15PhosphorusP
16SulphurS
17ChlorineCl
18ArgonAr
19PotassiumK
20CalciumCa

Important Groups

GroupFamilyExample
1Alkali MetalsLi, Na, K
2Alkaline Earth MetalsMg, Ca
17HalogensF, Cl, Br, I
18Noble GasesHe, Ne, Ar

IMPORTANT FACTS

  • Modern Periodic Law is based on atomic number.

  • Mendeleev arranged elements by atomic mass.

  • Moseley arranged elements by atomic number.

  • 7 Periods, 18 Groups.

  • Hydrogen is unique and shows properties of both Group 1 and Group 17.

  • Fluorine is the most electronegative element.

  • Cesium is among the most electropositive stable elements.

  • Aluminium is the most abundant metal in Earth's crust.

  • Oxygen is the most abundant element in Earth's crust.

  • Nitrogen is the most abundant gas in the atmosphere.

  • Carbon forms the maximum number of compounds.

PREVIOUS YEAR EXAM CONCEPTS

✔ Modern Periodic Law

✔ Mendeleev and Moseley

✔ Number of periods and groups

✔ Alkali metals and halogens

✔ Noble gases

✔ Most abundant element/metal

✔ Most electronegative element

✔ Atomic size trend

✔ Metallic character trend

✔ Reactivity trend

✔ First 20 elements and symbols

✔ Metalloids

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. The Modern Periodic Table is based on atomic number.

  2. Mendeleev arranged elements by atomic mass.

  3. The Modern Periodic Table has 18 groups.

  4. The Modern Periodic Table has 8 periods.

A. 1, 2 and 3 only
B. 1 and 4 only
C. 2 and 4 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct?

  1. Alkali metals belong to Group 1.

  2. Halogens belong to Group 17.

  3. Noble gases belong to Group 18.

  4. Transition metals belong to Group 2.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q3. Which statements are correct?

  1. Atomic radius decreases across a period.

  2. Atomic radius increases down a group.

  3. Metallic character decreases across a period.

  4. Electronegativity generally increases across a period.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q4. Which of the following are metalloids?

  1. Silicon

  2. Germanium

  3. Boron

  4. Sodium

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q5. Which statements are correct?

  1. Fluorine is the most electronegative element.

  2. Aluminium is the most abundant metal in Earth's crust.

  3. Oxygen is the most abundant element in Earth's crust.

  4. Nitrogen is the most abundant gas in Earth's atmosphere.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

PRACTICE MCQs

1. Who proposed the Modern Periodic Law?
A. Dmitri Mendeleev
B. Henry Moseley
C. John Newlands
D. Dobereiner
Answer: B

2. How many groups are present in the Modern Periodic Table?
A. 7
B. 8
C. 18
D. 20
Answer: C

3. Which group contains the noble gases?
A. Group 1
B. Group 2
C. Group 17
D. Group 18
Answer: D

4. Which element is the most electronegative?
A. Oxygen
B. Chlorine
C. Nitrogen
D. Fluorine
Answer: D

5. Which element is the most abundant metal in the Earth's crust?
A. Iron
B. Copper
C. Aluminium
D. Calcium
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Modern Periodic Law → Henry Moseley
Mendeleev → Atomic Mass
Modern Table → Atomic Number
7 Periods, 18 Groups
Group 1 → Alkali Metals
Group 2 → Alkaline Earth Metals
Group 17 → Halogens
Group 18 → Noble Gases
Atomic size ↓ across a period, ↑ down a group
Metallic character ↓ across a period, ↑ down a group
Fluorine → Most electronegative
Hydrogen → Lightest element
Oxygen → Most abundant element in Earth's crust
Aluminium → Most abundant metal in Earth's crust
Nitrogen → Most abundant gas in air

Carbon → Maximum number of compounds


CHAPTER 7 : CELL – STRUCTURE AND FUNCTIONS (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

  • Discovery of Cell

  • Cell Theory

  • Cell Structure

  • Prokaryotic and Eukaryotic Cells

  • Plant Cell vs Animal Cell

  • Cell Organelles

  • Cell Division

  • Chromosomes, DNA and Genes

  • Osmosis and Diffusion

QUICK REVISION (120+ One-Liner Points)

Basic Concepts

  1. Cell is the basic structural and functional unit of life.

  2. All living organisms are made up of cells.

  3. Cell was discovered by Robert Hooke in 1665.

  4. Robert Hooke observed dead cork cells.

  5. Antonie van Leeuwenhoek first observed living cells.

  6. Robert Brown discovered the nucleus (1831).

  7. Schleiden stated that plants are made of cells.

  8. Schwann stated that animals are made of cells.

  9. Rudolf Virchow proposed "Omnis cellula e cellula" (all cells arise from pre-existing cells).

  10. Cell theory was proposed by Schleiden and Schwann and later modified by Virchow.

Cell Theory

  1. Cell is the basic unit of structure.

  2. Cell is the basic unit of function.

  3. New cells arise from pre-existing cells.

  4. Cell theory applies to all living organisms.

  5. Viruses are not included in classical cell theory because they are acellular.

Types of Cells

  1. Cells are of two major types.

  2. Prokaryotic cells lack a true nucleus.

  3. Eukaryotic cells possess a true nucleus.

  4. Bacteria are prokaryotic.

  5. Cyanobacteria are prokaryotic.

  6. Amoeba is a unicellular eukaryote.

  7. Paramecium is a unicellular eukaryote.

  8. Fungi are eukaryotic.

  9. Plants are eukaryotic.

  10. Animals are eukaryotic.

Cell Shape

  1. Cell shape depends on function.

  2. Red blood cells are biconcave.

  3. Nerve cells are long and branched.

  4. Muscle cells are elongated.

  5. White blood cells change shape.

  6. Amoeba has no fixed shape.

  7. Plant cells are generally rectangular.

Cell Membrane

  1. Cell membrane is selectively permeable.

  2. Plasma membrane surrounds the cell.

  3. It controls entry and exit of substances.

  4. It is made mainly of lipids and proteins.

  5. Diffusion occurs through the membrane.

  6. Osmosis occurs through the selectively permeable membrane.

Cell Wall

  1. Cell wall is present in plant cells.

  2. Cell wall is absent in animal cells.

  3. Cell wall is made of cellulose.

  4. Cell wall provides rigidity.

  5. Cell wall gives shape and protection.

Cytoplasm

  1. Cytoplasm is a jelly-like substance.

  2. Organelles are suspended in cytoplasm.

  3. Most metabolic reactions occur in cytoplasm.

Nucleus

  1. Nucleus is the control center of the cell.

  2. Nucleus contains chromosomes.

  3. Nuclear membrane surrounds the nucleus.

  4. Nucleolus is present inside the nucleus.

  5. DNA is present in chromosomes.

  6. Genes are located on chromosomes.

  7. Genes carry hereditary information.

  8. Human somatic cells contain 46 chromosomes.

  9. Human gametes contain 23 chromosomes.

Mitochondria

  1. Mitochondria are called the powerhouse of the cell.

  2. Cellular respiration occurs in mitochondria.

  3. ATP is produced in mitochondria.

  4. Mitochondria possess their own DNA.

  5. Mitochondria are double-membraned.

Endoplasmic Reticulum (ER)

  1. ER transports materials within the cell.

  2. Rough ER has ribosomes.

  3. Smooth ER lacks ribosomes.

  4. Rough ER synthesizes proteins.

  5. Smooth ER synthesizes lipids.

  6. Smooth ER helps in detoxification.

Ribosomes

  1. Ribosomes are the sites of protein synthesis.

  2. Ribosomes are non-membranous organelles.

  3. Ribosomes occur free or attached to rough ER.

Golgi Apparatus

  1. Discovered by Camillo Golgi.

  2. Golgi apparatus modifies proteins.

  3. Golgi packages and secretes substances.

  4. Lysosomes are formed by the Golgi apparatus.

Lysosomes

  1. Lysosomes contain digestive enzymes.

  2. Lysosomes digest worn-out organelles.

  3. Lysosomes are called suicidal bags of the cell.

  4. Lysosomes are abundant in animal cells.

Plastids

  1. Plastids occur only in plant cells.

  2. Chloroplast is a green plastid.

  3. Chlorophyll is present in chloroplast.

  4. Photosynthesis occurs in chloroplast.

  5. Chromoplast provides colour to fruits and flowers.

  6. Leucoplast stores food.

Vacuoles

  1. Vacuoles store water and food.

  2. Plant cells have one large central vacuole.

  3. Animal cells have small temporary vacuoles.

  4. Vacuoles help maintain turgor pressure.

Centrosome

  1. Centrosome is present in animal cells.

  2. Centrosome is absent in higher plant cells.

  3. Centrosome helps in cell division.

Cell Division

  1. Cell division forms new cells.

  2. Mitosis is equational division.

  3. Meiosis is reduction division.

  4. Mitosis produces two identical daughter cells.

  5. Meiosis produces four daughter cells.

  6. Meiosis occurs in reproductive organs.

  7. Mitosis occurs in somatic cells.

  8. Mitosis helps in growth.

  9. Mitosis helps in repair.

  10. Meiosis maintains chromosome number in species.

Diffusion and Osmosis

  1. Diffusion is movement from higher to lower concentration.

  2. Diffusion does not require a membrane.

  3. Osmosis is movement of water through a selectively permeable membrane.

  4. Osmosis occurs from dilute to concentrated solution.

  5. Raisins swell in water due to osmosis.

  6. Plant roots absorb water by osmosis.

  7. Guard cells function through osmosis.

  8. Salt causes vegetables to lose water by osmosis.

Important Cell Facts

  1. Smallest known free-living cell – Mycoplasma.

  2. Largest cell – Ostrich egg.

  3. Longest cell – Nerve cell (Neuron).

  4. Largest human cell – Ovum.

  5. Smallest human cell – Sperm.

  6. Human body has trillions of cells.

  7. RBC in mammals lack a nucleus when mature.

  8. WBC possess a nucleus.

  9. Mature sieve tube elements lack a nucleus.

  10. Chloroplast contains its own DNA.

  11. Mitochondria contain their own DNA.

  12. ATP is known as the energy currency of the cell.

IMPORTANT TABLES

Scientists and Discoveries

ScientistContribution
Robert HookeDiscovered cell
Antonie van LeeuwenhoekFirst observed living cells
Robert BrownDiscovered nucleus
SchleidenPlant cell theory
SchwannAnimal cell theory
Rudolf VirchowCells arise from pre-existing cells
Camillo GolgiGolgi apparatus

Cell Organelles and Functions

OrganelleFunction
NucleusControls cell activities
MitochondriaATP production
RibosomesProtein synthesis
Rough ERProtein transport and synthesis
Smooth ERLipid synthesis, detoxification
Golgi ApparatusPackaging and secretion
LysosomesIntracellular digestion
ChloroplastPhotosynthesis
VacuoleStorage
Cell WallSupport and protection
Cell MembraneSelective transport

Plant Cell vs Animal Cell

Plant CellAnimal Cell
Cell wall presentCell wall absent
Chloroplast presentChloroplast absent
Large central vacuoleSmall vacuoles
Centrosome absent (higher plants)Centrosome present
Usually rectangularUsually irregular or rounded

PREVIOUS YEAR EXAM CONCEPTS

✔ Discovery of cell

✔ Cell theory

✔ Powerhouse of the cell

✔ Suicidal bag of the cell

✔ Site of protein synthesis

✔ Site of photosynthesis

✔ Control centre of the cell

✔ Plant cell vs animal cell

✔ Prokaryotic vs eukaryotic cells

✔ Mitosis vs meiosis

✔ Chromosome number in humans

✔ Largest and smallest cells

✔ Diffusion and osmosis

VERY IMPORTANT FACTS

  • Cell discovered by Robert Hooke (1665).

  • Living cells first observed by Antonie van Leeuwenhoek.

  • Nucleus discovered by Robert Brown.

  • Mitochondria = Powerhouse of the cell.

  • Ribosomes = Protein factories.

  • Golgi apparatus = Packaging centre.

  • Lysosomes = Suicidal bags.

  • Chloroplast = Photosynthesis.

  • ATP = Energy currency of the cell.

  • Human somatic cells = 46 chromosomes.

  • Human gametes = 23 chromosomes.

  • Largest cell = Ostrich egg.

  • Longest cell = Neuron.

  • Smallest free-living cell = Mycoplasma.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Robert Hooke discovered the cell.

  2. Robert Brown discovered the nucleus.

  3. Virchow stated that cells arise from pre-existing cells.

  4. Leeuwenhoek first observed living cells.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q2. Which of the following statements are correct?

  1. Mitochondria produce ATP.

  2. Ribosomes synthesize proteins.

  3. Chloroplast performs photosynthesis.

  4. Lysosomes contain digestive enzymes.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q3. Which of the following are found only in plant cells?

  1. Cell wall

  2. Chloroplast

  3. Large central vacuole

  4. Centrosome

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q4. Which statements are correct regarding cell division?

  1. Mitosis is equational division.

  2. Meiosis reduces chromosome number by half.

  3. Mitosis produces two daughter cells.

  4. Meiosis produces four daughter cells.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Which statements are correct?

  1. Diffusion occurs from higher to lower concentration.

  2. Osmosis requires a selectively permeable membrane.

  3. Plant roots absorb water mainly by osmosis.

  4. Mature mammalian RBCs lack a nucleus.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

PRACTICE MCQs

1. Who discovered the cell?
A. Robert Brown
B. Robert Hooke
C. Virchow
D. Schwann
Answer: B

2. Which organelle is known as the powerhouse of the cell?
A. Nucleus
B. Golgi apparatus
C. Mitochondrion
D. Ribosome
Answer: C

3. Which organelle is the site of protein synthesis?
A. Lysosome
B. Ribosome
C. Vacuole
D. Chloroplast
Answer: B

4. Which cell organelle contains chlorophyll?
A. Vacuole
B. Chloroplast
C. Nucleus
D. Lysosome
Answer: B

5. How many chromosomes are present in a normal human somatic cell?
A. 23
B. 44
C. 46
D. 48
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Robert Hooke → Cell (1665)
Leeuwenhoek → First living cell
Robert Brown → Nucleus
Virchow → Cells arise from pre-existing cells
Mitochondria → Powerhouse (ATP)
Ribosomes → Protein synthesis
Golgi apparatus → Packaging and secretion
Lysosomes → Suicidal bags
Chloroplast → Photosynthesis
Cell membrane → Selectively permeable
Cell wall → Cellulose, support
Mitosis → Growth and repair (2 daughter cells)
Meiosis → Gamete formation (4 daughter cells)
Human somatic cells → 46 chromosomes
Human gametes → 23 chromosomes
Largest cell → Ostrich egg
Longest cell → Neuron

Smallest free-living cell → Mycoplasma

CHAPTER 8 : SOURCES OF ENERGY (CONVENTIONAL & NON-CONVENTIONAL) – JKSSB General Science

JKSSB Exam Weightage

Frequently Asked Topics:

  • Sources of Energy

  • Conventional and Non-Conventional Sources

  • Fossil Fuels

  • Biomass and Biogas

  • Hydroelectric Energy

  • Wind Energy

  • Solar Energy

  • Tidal, Wave and Ocean Thermal Energy

  • Geothermal Energy

  • Nuclear Energy

  • Hydrogen Fuel

  • Advantages and Disadvantages

  • Environmental Impact

QUICK REVISION (120+ One-Liner Points)

Basic Concepts

  1. Energy is the capacity to do work.

  2. SI unit of energy is Joule (J).

  3. Commercial unit of electrical energy is kilowatt-hour (kWh).

  4. 1 kWh = 3.6 × 10⁶ Joules.

  5. An ideal source of energy should be economical.

  6. It should be easily available.

  7. It should produce maximum energy.

  8. It should be easy to transport.

  9. It should be environmentally friendly.

  10. No source of energy is completely ideal.

Conventional Sources of Energy

Fossil Fuels

  1. Coal is a fossil fuel.

  2. Petroleum is a fossil fuel.

  3. Natural gas is a fossil fuel.

  4. Fossil fuels are non-renewable.

  5. Fossil fuels take millions of years to form.

  6. Coal is mainly carbon.

  7. Petroleum is called black gold.

  8. Natural gas mainly contains methane.

  9. LPG stands for Liquefied Petroleum Gas.

  10. LPG mainly contains propane and butane.

  11. CNG stands for Compressed Natural Gas.

  12. CNG is mainly methane.

  13. Fossil fuels cause air pollution.

  14. Burning coal releases carbon dioxide.

  15. Fossil fuels contribute to global warming.

Thermal Power Plants

  1. Coal is the major fuel in thermal power plants.

  2. Steam rotates turbines.

  3. Turbines drive generators.

  4. Electricity is produced by electromagnetic induction.

  5. Ash disposal is a major problem.

  6. Thermal plants emit greenhouse gases.

Hydroelectric Energy

  1. Hydroelectric energy is renewable.

  2. Water stored in dams rotates turbines.

  3. It is a clean source of energy.

  4. Large dams may affect biodiversity.

  5. Bhakra Nangal is a major hydroelectric project.

  6. Tehri Dam is an important hydroelectric project.

  7. Water is the working medium.

  8. Hydropower depends on rainfall.

  9. It produces no smoke during operation.

Biomass

  1. Biomass includes plant and animal waste.

  2. Wood is a biomass fuel.

  3. Crop residues are biomass.

  4. Cow dung is biomass.

  5. Biomass is renewable.

  6. Biomass produces less sulphur pollution than coal.

  7. Biomass is converted into biogas.

  8. Biomass briquettes are cleaner fuels.

  9. Charcoal burns more efficiently than wood.

  10. Biomass can be used for electricity generation.

Biogas

  1. Biogas is produced by anaerobic decomposition.

  2. Gobar gas is another name for biogas.

  3. Methane is the major component of biogas.

  4. Biogas is a clean fuel.

  5. Slurry is used as manure.

  6. Biogas plants reduce waste.

  7. Rural households commonly use biogas.

  8. Biogas reduces deforestation.

  9. Methane burns with a blue flame.

  10. Biogas reduces indoor air pollution.

Wind Energy

  1. Wind energy is renewable.

  2. Wind turbines convert kinetic energy into electricity.

  3. Wind farms require open areas.

  4. Wind energy is pollution-free.

  5. Wind speed should be sufficiently high.

  6. Coastal regions are suitable for wind farms.

  7. Rajasthan has major wind energy projects.

  8. Gujarat has major wind farms.

  9. Tamil Nadu is a leading producer of wind energy.

  10. Wind energy is intermittent.

Non-Conventional Sources of Energy

Solar Energy

  1. Solar energy is renewable.

  2. Sun is the ultimate source of energy.

  3. Solar cells convert sunlight into electricity.

  4. Solar cells use the photovoltaic effect.

  5. Silicon is used in solar cells.

  6. Solar cookers use solar energy.

  7. Solar water heaters reduce electricity consumption.

  8. Solar panels produce DC electricity.

  9. Solar energy is pollution-free during operation.

  10. Solar energy depends on sunlight availability.

Tidal Energy

  1. Tidal energy is generated by sea tides.

  2. It depends on the gravitational pull of the Moon and Sun.

  3. High and low tides generate electricity.

  4. Tidal energy is renewable.

  5. It is available only in suitable coastal areas.

Wave Energy

  1. Wave energy is produced by sea waves.

  2. Strong winds generate waves.

  3. Wave energy is renewable.

  4. Wave power plants are located near coastlines.

Ocean Thermal Energy (OTEC)

  1. OTEC uses the temperature difference between surface and deep ocean water.

  2. Minimum temperature difference required is about 20°C.

  3. OTEC is renewable.

  4. Suitable mainly in tropical oceans.

Geothermal Energy

  1. Geothermal energy comes from Earth's internal heat.

  2. Hot springs are sources of geothermal energy.

  3. Geothermal energy is renewable.

  4. Iceland uses geothermal energy extensively.

  5. It produces very low emissions.

Nuclear Energy

  1. Nuclear energy is obtained by nuclear fission.

  2. Uranium-235 is commonly used as fuel.

  3. Plutonium-239 can also be used as fuel.

  4. Nuclear reactors generate electricity.

  5. Nuclear energy produces large amounts of energy.

  6. Radioactive waste disposal is a major challenge.

  7. Nuclear power emits very low greenhouse gases during operation.

  8. India has several nuclear power stations.

Hydrogen Fuel

  1. Hydrogen has a high calorific value.

  2. Burning hydrogen produces water.

  3. Hydrogen is considered a clean fuel.

  4. Storage of hydrogen is difficult.

  5. Fuel cells use hydrogen to generate electricity.

Energy Conservation

  1. Switch off unused electrical appliances.

  2. Use LED bulbs instead of incandescent bulbs.

  3. Use energy-efficient appliances.

  4. Promote renewable energy.

  5. Reduce fossil fuel consumption.

  6. Public transport saves energy.

  7. Energy conservation reduces pollution.

  8. Energy conservation reduces greenhouse gas emissions.

  9. Sustainable development requires efficient energy use.

IMPORTANT FORMULAS & VALUES

QuantityValue
SI Unit of EnergyJoule (J)
Commercial UnitkWh
1 kWh3.6 × 10⁶ J
Major Component of BiogasMethane
Fuel of Nuclear ReactorUranium-235
Solar Cell PrinciplePhotovoltaic Effect

IMPORTANT TABLE

SourceTypeRenewableMain Limitation
CoalConventionalNoAir pollution
PetroleumConventionalNoExhaustible
Natural GasConventionalNoLimited reserves
HydroelectricConventionalYesDepends on rainfall
BiomassConventionalYesLow energy density
WindConventionalYesIntermittent
SolarNon-conventionalYesSunlight dependent
TidalNon-conventionalYesLimited suitable sites
GeothermalNon-conventionalYesGeographically restricted
NuclearNon-conventionalNo*Radioactive waste

*Nuclear energy is often grouped separately in textbooks. It relies on finite fuels such as uranium, so the fuel itself is non-renewable.

PREVIOUS YEAR EXAM CONCEPTS

✔ Renewable vs non-renewable energy

✔ Biogas composition

✔ LPG vs CNG

✔ Solar cells

✔ Wind energy

✔ Hydroelectric power

✔ Nuclear fuel

✔ Photovoltaic effect

✔ Biomass

✔ Fossil fuels

✔ Greenhouse gas emissions

✔ Commercial unit of electricity

✔ Advantages and disadvantages of energy sources

VERY IMPORTANT FACTS

  • Sun is the ultimate source of most energy on Earth.

  • 1 kWh = 3.6 × 10⁶ J

  • Petroleum = Black Gold

  • Natural gas = Mainly methane

  • Biogas = Mainly methane

  • Solar cells use the photovoltaic effect.

  • Silicon is used in solar cells.

  • Wind energy is clean but intermittent.

  • Hydroelectric energy is renewable.

  • Uranium-235 is used in nuclear reactors.

  • Hydrogen is considered a clean fuel because it forms water on burning.

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Coal is a fossil fuel.

  2. Petroleum is renewable.

  3. Natural gas mainly contains methane.

  4. Fossil fuels contribute to global warming.

A. 1, 3 and 4 only
B. 1 and 2 only
C. 2 and 4 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct?

  1. Biogas is produced by anaerobic decomposition.

  2. Methane is the major component of biogas.

  3. Slurry from a biogas plant is used as manure.

  4. Biogas is a renewable source of energy.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q3. Which statements are correct?

  1. Solar cells work on the photovoltaic effect.

  2. Silicon is commonly used in solar cells.

  3. Solar energy is renewable.

  4. Solar panels generate direct current (DC).

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q4. Which of the following statements are correct?

  1. Wind energy is renewable.

  2. Hydroelectric power depends on rainfall.

  3. Nuclear reactors commonly use Uranium-235.

  4. Radioactive waste disposal is a challenge in nuclear power.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Which of the following are renewable energy sources?

  1. Solar energy

  2. Wind energy

  3. Geothermal energy

  4. Coal

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

PRACTICE MCQs

1. The commercial unit of electrical energy is:
A. Joule
B. Watt
C. Kilowatt-hour (kWh)
D. Newton
Answer: C

2. The major component of biogas is:
A. Hydrogen
B. Oxygen
C. Methane
D. Carbon dioxide
Answer: C

3. Solar cells convert solar energy into electrical energy by the:
A. Photoelectric effect
B. Photovoltaic effect
C. Greenhouse effect
D. Thermoelectric effect
Answer: B

4. Which fuel is commonly used in nuclear power plants?
A. Coal
B. Uranium-235
C. Diesel
D. Hydrogen
Answer: B

5. Which Indian state is a leading producer of wind energy?
A. Punjab
B. Bihar
C. Tamil Nadu
D. Assam
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

SI unit of energy → Joule (J)
Commercial unit → kWh
1 kWh = 3.6 × 10⁶ J
Fossil fuels → Coal, Petroleum, Natural Gas
Petroleum → Black Gold
LPG → Propane + Butane
CNG → Mainly Methane
Biogas → Mainly Methane
Solar cell → Photovoltaic effect
Silicon → Solar cells
Hydroelectric → Renewable
Wind → Renewable, pollution-free
Nuclear fuel → Uranium-235
Hydrogen → Clean fuel (forms water on burning)

Energy conservation → LED bulbs, efficient appliances, renewable energy, public transport

CHAPTER 9 : LIFE PROCESSES (NUTRITION, RESPIRATION, TRANSPORTATION & EXCRETION) – JKSSB General Science

JKSSB Exam Weightage

Frequently Asked Topics:

  • Life Processes

  • Nutrition and its Types

  • Human Digestive System

  • Respiration

  • Transportation in Humans

  • Transportation in Plants

  • Excretion in Humans

  • Excretion in Plants

  • Important Enzymes

  • Blood Components

  • Heart and Circulation

QUICK REVISION (150+ One-Liner Points)

Basic Concepts

  1. Life processes are activities essential for survival.

  2. Major life processes are nutrition, respiration, transportation and excretion.

  3. Growth and reproduction are not essential for the survival of an individual.

  4. Energy for life processes is obtained from food.

  5. ATP is the energy currency of the cell.

NUTRITION

Nutrition

  1. Nutrition is the process of obtaining and utilizing food.

  2. Food provides energy.

  3. Food is needed for growth.

  4. Food helps repair body tissues.

  5. Food regulates body functions.

Types of Nutrition

  1. Two major types are autotrophic and heterotrophic.

  2. Green plants are autotrophs.

  3. Photosynthesis is autotrophic nutrition.

  4. Animals are heterotrophs.

  5. Humans exhibit holozoic nutrition.

  6. Fungi show saprophytic nutrition.

  7. Tapeworm is parasitic.

  8. Pitcher plant is insectivorous.

  9. Cuscuta is a parasitic plant.

  10. Lichens show symbiotic nutrition.

Photosynthesis

  1. Photosynthesis occurs in chloroplasts.

  2. Chlorophyll traps sunlight.

  3. Carbon dioxide enters through stomata.

  4. Water is absorbed by roots.

  5. Oxygen is released during photosynthesis.

  6. Glucose is the main product.

  7. Sunlight is essential.

  8. Photosynthesis converts solar energy into chemical energy.

  9. Stomata regulate gaseous exchange.

  10. Guard cells control stomatal opening.

Photosynthesis Equation

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in presence of sunlight and chlorophyll)

HUMAN DIGESTIVE SYSTEM

  1. Digestion begins in the mouth.

  2. Saliva contains salivary amylase (ptyalin).

  3. Salivary amylase digests starch.

  4. Teeth perform mechanical digestion.

  5. Tongue helps in swallowing.

  6. Oesophagus transports food.

  7. Peristalsis moves food.

  8. Hydrochloric acid is secreted in the stomach.

  9. Pepsin digests proteins.

  10. Mucus protects the stomach lining.

  11. Liver is the largest gland in the body.

  12. Liver secretes bile.

  13. Bile contains no digestive enzymes.

  14. Bile emulsifies fats.

  15. Gall bladder stores bile.

  16. Pancreas secretes pancreatic juice.

  17. Trypsin digests proteins.

  18. Lipase digests fats.

  19. Amylase digests carbohydrates.

  20. Most digestion is completed in the small intestine.

  21. Villi increase the surface area for absorption.

  22. Nutrients are absorbed in the small intestine.

  23. Water is absorbed mainly in the large intestine.

  24. Undigested food is expelled through the anus.

IMPORTANT DIGESTIVE ENZYMES

EnzymeSecreted ByFunction
Salivary Amylase (Ptyalin)Salivary glandsStarch → Maltose
PepsinStomachProteins → Peptides
TrypsinPancreasProteins → Peptides
LipasePancreasFats → Fatty acids + Glycerol
AmylasePancreasStarch digestion

RESPIRATION

  1. Respiration releases energy.

  2. ATP is formed during respiration.

  3. Respiration occurs in mitochondria.

  4. Oxygen is required for aerobic respiration.

  5. Anaerobic respiration occurs without oxygen.

  6. Aerobic respiration releases more energy.

  7. Anaerobic respiration releases less energy.

  8. Human muscles perform anaerobic respiration during vigorous exercise.

  9. Lactic acid accumulates in muscles.

  10. Muscle cramps occur due to lactic acid.

  11. Yeast performs anaerobic respiration.

  12. Yeast produces alcohol and carbon dioxide.

  13. Breathing and respiration are different processes.

  14. Gas exchange occurs in alveoli.

  15. Alveoli provide a large surface area.

  16. Diaphragm helps in breathing.

Aerobic Respiration

Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)

Anaerobic Respiration (Yeast)

Glucose → Alcohol + Carbon dioxide + Energy

TRANSPORTATION IN HUMANS

  1. Blood transports materials.

  2. Blood is a connective tissue.

  3. Blood consists of plasma and blood cells.

  4. Plasma is the liquid part of blood.

  5. RBCs transport oxygen.

  6. Haemoglobin is present in RBCs.

  7. WBCs fight infections.

  8. Platelets help in blood clotting.

  9. Plasma transports nutrients and hormones.

  10. Human heart has four chambers.

  11. Right atrium receives deoxygenated blood.

  12. Left atrium receives oxygenated blood.

  13. Left ventricle pumps oxygenated blood to the body.

  14. Right ventricle pumps blood to the lungs.

  15. The human heart is myogenic.

  16. Heartbeat is controlled by the SA node (natural pacemaker).

  17. Pulmonary artery carries deoxygenated blood.

  18. Pulmonary vein carries oxygenated blood.

  19. Aorta is the largest artery.

  20. Arteries carry blood away from the heart.

  21. Veins carry blood towards the heart.

  22. Capillaries are the thinnest blood vessels.

  23. Exchange of materials occurs through capillaries.

  24. Double circulation occurs in humans.

  25. Humans have closed circulatory systems.

BLOOD GROUPS

  1. Blood groups are A, B, AB and O.

  2. AB is the universal recipient.

  3. O negative is the universal donor.

  4. Rh factor determines positive or negative blood groups.

  5. Blood transfusion requires compatible blood groups.

LYMPH

  1. Lymph is colourless.

  2. Lymph transports fats.

  3. Lymph contains lymphocytes.

  4. Lymph helps immunity.

TRANSPORTATION IN PLANTS

  1. Xylem transports water.

  2. Xylem transports minerals.

  3. Phloem transports food.

  4. Water moves upward due to transpiration pull.

  5. Root pressure also helps water movement.

  6. Transpiration occurs through stomata.

  7. Transpiration cools plants.

  8. Root hairs absorb water.

  9. Osmosis helps water absorption.

EXCRETION IN HUMANS

  1. Excretion removes metabolic waste.

  2. Kidneys are the main excretory organs.

  3. Humans have two kidneys.

  4. Nephron is the structural and functional unit of the kidney.

  5. Urine is formed in nephrons.

  6. Urea is the main nitrogenous waste in humans.

  7. Ureter carries urine to the urinary bladder.

  8. Urinary bladder stores urine.

  9. Urethra expels urine.

  10. Dialysis removes waste from blood when kidneys fail.

  11. Skin excretes sweat.

  12. Lungs excrete carbon dioxide and water vapour.

EXCRETION IN PLANTS

  1. Plants have no specialized excretory organs.

  2. Oxygen is released during photosynthesis.

  3. Carbon dioxide is released during respiration.

  4. Excess water is lost through transpiration.

  5. Gums and resins are excretory products.

  6. Latex is an excretory product.

  7. Leaves store waste before falling.

IMPORTANT FACTS

  1. Largest gland – Liver.

  2. Largest organ – Skin.

  3. Longest part of the alimentary canal – Small intestine.

  4. Small intestine is about 6–7 metres long.

  5. Human heart beats about 72 times per minute (average adult at rest).

  6. Normal body temperature is about 37°C.

  7. Normal blood pH is about 7.4.

  8. Haemoglobin contains iron.

  9. RBC lifespan is about 120 days.

  10. WBC lifespan varies with type.

  11. Platelets help stop bleeding.

  12. Bile is alkaline.

  13. Pancreas has both endocrine and exocrine functions.

  14. Insulin is secreted by the pancreas.

  15. Diabetes mellitus is associated with insulin deficiency or resistance.

  16. Kidneys help regulate water and salt balance.

  17. Healthy kidneys also help maintain acid–base balance.

  18. ATP is produced mainly in mitochondria.

IMPORTANT TABLE

Blood Components

ComponentFunction
RBCTransport oxygen
WBCImmunity
PlateletsBlood clotting
PlasmaTransport nutrients, hormones and wastes

Xylem vs Phloem

XylemPhloem
Water transportFood transport
Mostly upward movementCan be bidirectional
Mostly dead cells (except xylem parenchyma)Mostly living cells (except fibres)

PREVIOUS YEAR EXAM CONCEPTS

✔ Photosynthesis equation

✔ Human digestive enzymes

✔ Largest gland

✔ Universal donor

✔ Universal recipient

✔ RBC, WBC, Platelets

✔ Human heart chambers

✔ Pulmonary artery and vein

✔ Xylem and phloem

✔ Nephron

✔ Kidney functions

✔ Aerobic and anaerobic respiration

✔ ATP production

✔ Urea

✔ Transpiration

VERY IMPORTANT FACTS

  • ATP = Energy currency

  • Mitochondria = Site of respiration

  • Chloroplast = Site of photosynthesis

  • Liver = Largest gland

  • Skin = Largest organ

  • Nephron = Functional unit of kidney

  • RBC = Oxygen transport

  • WBC = Immunity

  • Platelets = Blood clotting

  • AB = Universal recipient

  • O negative = Universal donor

  • Pulmonary artery = Deoxygenated blood

  • Pulmonary vein = Oxygenated blood

  • Xylem = Water

  • Phloem = Food

  • Small intestine = Maximum digestion and absorption

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Photosynthesis occurs in chloroplasts.

  2. Chlorophyll traps solar energy.

  3. Oxygen is released during photosynthesis.

  4. Stomata regulate gaseous exchange.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q2. Which of the following statements are correct?

  1. Pepsin digests proteins.

  2. Lipase digests fats.

  3. Bile contains digestive enzymes.

  4. Salivary amylase digests starch.

A. 1, 2 and 4 only
B. 2 and 3 only
C. 1 and 4 only
D. All are correct

Answer: A

Q3. Which statements are correct?

  1. RBCs transport oxygen.

  2. WBCs help fight infections.

  3. Platelets help in blood clotting.

  4. Plasma is the liquid part of blood.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q4. Which of the following statements are correct?

  1. Xylem transports water.

  2. Phloem transports food.

  3. Nephron is the functional unit of the kidney.

  4. Urea is the main nitrogenous waste in humans.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Consider the following statements:

  1. Pulmonary artery carries deoxygenated blood.

  2. Pulmonary vein carries oxygenated blood.

  3. The human heart has four chambers.

  4. Double circulation occurs in humans.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

PRACTICE MCQs

1. Which organ secretes bile?
A. Pancreas
B. Liver
C. Gall bladder
D. Stomach
Answer: B

2. The functional unit of the kidney is:
A. Alveolus
B. Neuron
C. Nephron
D. Villus
Answer: C

3. Which blood vessel carries oxygenated blood from the lungs to the heart?
A. Pulmonary artery
B. Aorta
C. Pulmonary vein
D. Vena cava
Answer: C

4. Which blood component is responsible for clotting?
A. RBC
B. WBC
C. Plasma
D. Platelets
Answer: D

5. Which tissue transports food in plants?
A. Xylem
B. Phloem
C. Cortex
D. Epidermis
Answer: B

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Nutrition → Autotrophic & Heterotrophic
Photosynthesis → 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Chloroplast → Photosynthesis
Mitochondria → ATP production
Liver → Largest gland; secretes bile
Bile → Emulsifies fats (no enzymes)
Pepsin → Protein digestion
Lipase → Fat digestion
Small intestine → Maximum digestion & absorption
RBC → Oxygen transport
WBC → Immunity
Platelets → Clotting
Heart → 4 chambers
Pulmonary artery → Deoxygenated blood
Pulmonary vein → Oxygenated blood
Xylem → Water & minerals
Phloem → Food
Kidney → Excretion
Nephron → Functional unit of kidney

Urea → Main nitrogenous waste in humans

CHAPTER 10 : ENVIRONMENTAL POLLUTION, ECOSYSTEM, FOOD CHAIN, OZONE LAYER & GREENHOUSE EFFECT (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics:

Environmental Pollution

Types of Pollution
Air Pollutants
Water Pollution
Soil Pollution
Noise Pollution
Solid Waste Management
Biodegradable & Non-biodegradable Waste

Ecosystem

Components of Ecosystem
Food Chain & Food Web
Ecological Pyramid
Ozone Layer
Greenhouse Effect
Global Warming
Acid Rain
Important Environmental Conventions

QUICK REVISION (150+ One-Liner Points)

ENVIRONMENT

  1. Environment includes all living and non-living surroundings.

  2. Ecology is the study of interactions between organisms and their environment.

  3. Ernst Haeckel coined the term Ecology.

  4. Environment has biotic and abiotic components.

  5. Biotic components are living organisms.

  6. Abiotic components include air, water, soil and sunlight.

  7. Healthy ecosystems maintain ecological balance.

  8. Human activities disturb ecosystems.

  9. Sustainable development meets present needs without compromising future generations.

  10. Environmental conservation is essential for biodiversity.

ENVIRONMENTAL POLLUTION

  1. Pollution is the undesirable change in the environment.

  2. Pollutants are substances causing pollution.

  3. Pollution may be natural or man-made.

  4. Industrialization increases pollution.

  5. Urbanization contributes to pollution.

  6. Vehicular emissions are major air pollutants.

  7. Plastic pollution is a global concern.

  8. Waste management reduces pollution.

  9. The 3Rs are Reduce, Reuse and Recycle.

  10. Refuse and Recover are often added to modern waste management practices.

AIR POLLUTION

  1. Air pollution is contamination of the atmosphere.

  2. Carbon monoxide is a poisonous gas.

  3. Sulphur dioxide causes acid rain.

  4. Nitrogen oxides contribute to acid rain.

  5. Carbon dioxide is a greenhouse gas.

  6. Methane is a potent greenhouse gas.

  7. Particulate Matter (PM₂.₅ and PM₁₀) affects respiratory health.

  8. Ozone at ground level is a harmful pollutant.

  9. Smog is a mixture of smoke and fog.

  10. Photochemical smog contains ozone and nitrogen oxides.

  11. Acid rain damages monuments.

  12. Acid rain affects crops.

  13. Acid rain acidifies lakes.

  14. Taj Mahal is affected by acid rain and air pollution.

  15. Catalytic converters reduce harmful vehicle emissions.

WATER POLLUTION

  1. Water pollution makes water unfit for use.

  2. Sewage pollutes rivers.

  3. Industrial effluents pollute water.

  4. Oil spills pollute oceans.

  5. Fertilizers cause eutrophication.

  6. Pesticides contaminate groundwater.

  7. Clean drinking water prevents diseases.

  8. Boiling kills many disease-causing microorganisms.

  9. Chlorination disinfects water.

  10. Water treatment removes impurities.

SOIL POLLUTION

  1. Soil pollution reduces fertility.

  2. Excess fertilizers damage soil.

  3. Pesticides contaminate soil.

  4. Plastic waste degrades soil quality.

  5. Heavy metals pollute soil.

  6. Organic farming helps conserve soil.

  7. Compost improves soil fertility.

  8. Vermicomposting uses earthworms.

  9. Crop rotation improves soil health.

  10. Afforestation helps prevent soil erosion.

NOISE POLLUTION

  1. Noise pollution is unwanted sound.

  2. Loudspeakers increase noise pollution.

  3. Vehicle horns are major sources of noise.

  4. Industrial machines produce noise pollution.

  5. Prolonged exposure may cause hearing loss.

  6. Noise can increase stress.

  7. Green belts reduce noise.

RADIOACTIVE POLLUTION

  1. Radioactive pollution results from radioactive substances.

  2. Nuclear accidents can cause radioactive contamination.

  3. Radiation exposure can damage DNA.

  4. Safe disposal of radioactive waste is essential.

BIODEGRADABLE & NON-BIODEGRADABLE WASTE

  1. Biodegradable waste decomposes naturally.

  2. Vegetable waste is biodegradable.

  3. Paper is biodegradable.

  4. Cotton is biodegradable.

  5. Plastic is generally non-biodegradable.

  6. Glass is non-biodegradable.

  7. Aluminium cans are non-biodegradable but recyclable.

  8. E-waste requires scientific disposal.

  9. Recycling conserves natural resources.

ECOSYSTEM

  1. Ecosystem is a functional unit of nature.

  2. Sir Arthur Tansley coined the term Ecosystem.

  3. Ecosystem has biotic and abiotic components.

  4. Forest is a natural ecosystem.

  5. Pond is a natural ecosystem.

  6. Aquarium is an artificial ecosystem.

  7. Crop field is an artificial ecosystem.

  8. Sun is the ultimate source of energy in ecosystems.

  9. Energy flows in one direction.

  10. Nutrients are recycled in ecosystems.

BIOTIC COMPONENTS

  1. Producers prepare food.

  2. Green plants are producers.

  3. Consumers depend on producers.

  4. Herbivores are primary consumers.

  5. Carnivores are secondary or tertiary consumers.

  6. Omnivores eat plants and animals.

  7. Decomposers recycle nutrients.

  8. Bacteria are decomposers.

  9. Fungi are decomposers.

  10. Decomposers maintain nutrient cycles.

FOOD CHAIN

  1. Food chain shows transfer of food energy.

  2. It starts with producers.

  3. Herbivores occupy the second trophic level.

  4. Carnivores occupy higher trophic levels.

  5. Decomposers act on dead organisms from all trophic levels.

  6. Energy decreases at each trophic level.

  7. About 10% of energy is transferred to the next trophic level (10% law).

  8. Longer food chains are generally less energy efficient.

  9. Food chains maintain ecological balance.

  10. Removal of one species can affect the entire food chain.

Example

Grass → Grasshopper → Frog → Snake → Eagle

FOOD WEB

  1. Food web consists of interconnected food chains.

  2. Food webs increase ecosystem stability.

  3. One organism may occupy multiple food chains.

  4. Food webs provide alternative feeding pathways.

  5. Natural ecosystems usually have food webs.

ECOLOGICAL PYRAMID

  1. Ecological pyramids represent trophic levels.

  2. Pyramid of energy is always upright.

  3. Pyramid of numbers may be upright or inverted.

  4. Pyramid of biomass can be inverted in some aquatic ecosystems.

  5. Producers form the base of the pyramid.

OZONE LAYER

  1. Ozone layer is present in the stratosphere.

  2. Ozone consists of three oxygen atoms (O₃).

  3. Ozone absorbs harmful ultraviolet (UV) radiation.

  4. Ozone protects living organisms.

  5. Chlorofluorocarbons (CFCs) deplete ozone.

  6. Halons also contribute to ozone depletion.

  7. Ozone hole is largest over Antarctica during the Southern Hemisphere spring.

  8. Increased UV exposure can cause skin cancer.

  9. UV radiation can cause cataracts.

  10. Plants can also be affected by excessive UV radiation.

GREENHOUSE EFFECT

  1. Greenhouse effect warms Earth's surface.

  2. It is a natural phenomenon essential for life.

  3. Enhanced greenhouse effect leads to global warming.

  4. Carbon dioxide is the major anthropogenic greenhouse gas.

  5. Methane has a higher warming potential per molecule than carbon dioxide.

  6. Nitrous oxide is a greenhouse gas.

  7. Water vapour is a natural greenhouse gas.

  8. CFCs are also greenhouse gases.

  9. Global warming causes glacier melting.

  10. Sea level rises due to global warming.

  11. Climate change increases extreme weather events.

  12. Renewable energy helps reduce greenhouse gas emissions.

  13. Afforestation helps reduce atmospheric carbon dioxide.

  14. Deforestation increases global warming.

  15. Energy conservation reduces emissions.

IMPORTANT ENVIRONMENTAL DAYS

DayDate
World Environment Day5 June
World Water Day22 March
Earth Day22 April
World Ozone Day16 September
International Day of Forests21 March
World Wildlife Day3 March

IMPORTANT INTERNATIONAL AGREEMENTS

AgreementPurpose
Montreal Protocol (1987)Protect ozone layer by phasing out ozone-depleting substances
Kyoto Protocol (1997)Reduce greenhouse gas emissions
Paris Agreement (2015)Limit global warming through climate action
Ramsar ConventionConservation of wetlands
Convention on Biological Diversity (CBD)Biodiversity conservation

IMPORTANT TABLE

PollutantMain Effect
Carbon Monoxide (CO)Reduces oxygen transport in blood
Sulphur Dioxide (SO₂)Acid rain
Nitrogen Oxides (NOₓ)Acid rain & photochemical smog
Carbon Dioxide (CO₂)Greenhouse effect
Methane (CH₄)Greenhouse effect
CFCsOzone depletion
PM₂.₅Respiratory diseases

PREVIOUS YEAR EXAM CONCEPTS

✔ Biodegradable vs non-biodegradable waste

✔ Food chain

✔ Food web

✔ Producers and consumers

✔ Decomposers

✔ 10% law

✔ Ozone layer

✔ CFCs

✔ Greenhouse gases

✔ Acid rain

✔ World Environment Day

✔ Montreal Protocol

✔ Kyoto Protocol

✔ Paris Agreement

✔ Air and water pollution

VERY IMPORTANT FACTS

  • Ecology → Ernst Haeckel

  • Ecosystem → Arthur Tansley

  • Sun → Ultimate source of energy

  • Producers → Green plants

  • Decomposers → Bacteria and fungi

  • 10% law → Only ~10% energy passes to the next trophic level

  • Ozone (O₃) → Stratosphere

  • CFCs → Ozone depletion

  • CO₂, CH₄, N₂O, water vapour → Greenhouse gases

  • SO₂ and NOₓ → Acid rain

  • World Environment Day → 5 June

  • World Ozone Day → 16 September

  • Montreal Protocol → Ozone protection

  • Paris Agreement → Climate change mitigation

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Green plants are producers.

  2. Bacteria are decomposers.

  3. Energy transfer between trophic levels follows the 10% law.

  4. Food chains always begin with carnivores.

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct?

  1. Ozone is present mainly in the stratosphere.

  2. CFCs deplete the ozone layer.

  3. Ozone absorbs harmful UV radiation.

  4. Ozone depletion increases the risk of skin cancer.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q3. Which of the following are greenhouse gases?

  1. Carbon dioxide

  2. Methane

  3. Nitrous oxide

  4. Water vapour

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q4. Which statements are correct?

  1. Sulphur dioxide contributes to acid rain.

  2. Nitrogen oxides contribute to acid rain.

  3. Carbon monoxide is poisonous.

  4. PM₂.₅ can affect the respiratory system.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Which of the following are biodegradable?

  1. Vegetable waste

  2. Paper

  3. Cotton

  4. Plastic

A. 1, 2 and 3 only
B. 2 and 4 only
C. 1 and 4 only
D. All are correct

Answer: A

PRACTICE MCQs

1. Who coined the term "Ecosystem"?
A. Ernst Haeckel
B. Charles Darwin
C. Arthur Tansley
D. Linnaeus
Answer: C

2. Which gas is primarily responsible for ozone depletion?
A. Carbon dioxide
B. Methane
C. Chlorofluorocarbons (CFCs)
D. Oxygen
Answer: C

3. World Environment Day is celebrated on:
A. 22 April
B. 5 June
C. 16 September
D. 21 March
Answer: B

4. Which trophic level occupies the base of an ecological pyramid?
A. Producers
B. Primary consumers
C. Secondary consumers
D. Decomposers
Answer: A

5. Which international agreement specifically aims to protect the ozone layer?
A. Paris Agreement
B. Kyoto Protocol
C. Montreal Protocol
D. Ramsar Convention
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Ecology → Ernst Haeckel
Ecosystem → Arthur Tansley
Producers → Green plants
Consumers → Herbivores, carnivores, omnivores
Decomposers → Bacteria & fungi
Food chain starts with producers
10% law → Only ~10% energy transfers to the next trophic level
Ozone → O₃, found in the stratosphere
CFCs → Ozone depletion
CO₂, CH₄, N₂O → Greenhouse gases
SO₂ & NOₓ → Acid rain
PM₂.₅ → Harmful to lungs
World Environment Day → 5 June
World Ozone Day → 16 September
Montreal Protocol → Ozone protection
Paris Agreement → Climate change

3Rs → Reduce, Reuse, Recycle

CHAPTER 11 : MENDEL'S CONTRIBUTION, HEREDITY & REPRODUCTION IN PLANTS AND ANIMALS (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics

  • Mendel's Experiments

  • Laws of Inheritance

  • Dominant & Recessive Traits

  • Genes, DNA & Chromosomes

  • Variation

  • Types of Reproduction

  • Asexual Reproduction

  • Sexual Reproduction

  • Reproduction in Plants

  • Reproduction in Animals

  • Pollination

  • Fertilization

  • Seed Formation

  • Human Reproductive Facts (Basic)

QUICK REVISION (150+ One-Liner Points)

HEREDITY

  1. Heredity is the transmission of traits from parents to offspring.

  2. Genetics is the study of heredity and variation.

  3. Gregor Johann Mendel is known as the Father of Genetics.

  4. Mendel conducted experiments on pea plants (Pisum sativum).

  5. Mendel selected pea plants because they have clear contrasting characters.

  6. Pea plants have a short life cycle.

  7. Pea plants are naturally self-pollinating.

  8. Artificial cross-pollination is easy in pea plants.

  9. Genes are the units of heredity.

  10. Genes are located on chromosomes.

MENDEL'S EXPERIMENTS

  1. Mendel studied seven pairs of contrasting characters.

  2. Tall and dwarf are contrasting traits.

  3. Round and wrinkled seeds are contrasting traits.

  4. Yellow and green seeds are contrasting traits.

  5. Purple and white flowers are contrasting traits.

  6. Inflated and constricted pods are contrasting traits.

  7. Green and yellow pods are contrasting traits.

  8. Axial and terminal flowers are contrasting traits.

  9. F₁ generation showed only dominant traits.

  10. F₂ generation showed both dominant and recessive traits.

MENDEL'S LAWS

  1. First Law – Law of Dominance.

  2. Dominant traits mask recessive traits.

  3. Second Law – Law of Segregation.

  4. Alleles separate during gamete formation.

  5. Third Law – Law of Independent Assortment.

  6. Different traits assort independently (for genes that are unlinked).

IMPORTANT GENETIC TERMS

  1. Gene is the unit of heredity.

  2. Chromosomes carry genes.

  3. DNA carries genetic information.

  4. DNA stands for Deoxyribonucleic Acid.

  5. RNA stands for Ribonucleic Acid.

  6. Alleles are alternative forms of a gene.

  7. Genotype is the genetic makeup.

  8. Phenotype is the physical expression.

  9. Homozygous means identical alleles.

  10. Heterozygous means different alleles.

  11. Dominant alleles are usually represented by capital letters.

  12. Recessive alleles are usually represented by small letters.

  13. TT represents a homozygous dominant genotype.

  14. Tt represents a heterozygous genotype.

  15. tt represents a homozygous recessive genotype.

CHROMOSOMES

  1. Humans have 46 chromosomes in somatic cells.

  2. Human gametes contain 23 chromosomes.

  3. Chromosomes occur in pairs in diploid cells.

  4. Sex chromosomes determine sex.

  5. XX represents female.

  6. XY represents male.

  7. The father determines the sex of the child in humans.

  8. Autosomes are non-sex chromosomes.

  9. Humans have 22 pairs of autosomes.

VARIATION

  1. Variation makes organisms different.

  2. Variations help in evolution.

  3. Sexual reproduction produces more variation.

  4. Mutations also produce variation.

  5. Identical twins have very similar genetic makeup but may differ due to environmental influences.

REPRODUCTION

  1. Reproduction ensures continuity of species.

  2. Two major types are asexual and sexual reproduction.

  3. Asexual reproduction involves one parent.

  4. Sexual reproduction involves two parents.

  5. Asexual reproduction produces genetically similar offspring.

ASEXUAL REPRODUCTION

  1. Binary fission occurs in Amoeba.

  2. Binary fission occurs in Paramecium.

  3. Multiple fission occurs in Plasmodium.

  4. Budding occurs in Hydra.

  5. Budding occurs in Yeast.

  6. Fragmentation occurs in Spirogyra.

  7. Regeneration occurs in Planaria.

  8. Spore formation occurs in Rhizopus.

  9. Vegetative propagation occurs in plants.

  10. Potato reproduces by stem tuber.

  11. Ginger reproduces by rhizome.

  12. Onion reproduces by bulb.

  13. Sugarcane reproduces by stem cutting.

  14. Bryophyllum reproduces by leaf buds.

  15. Strawberry reproduces by runners.

SEXUAL REPRODUCTION IN PLANTS

  1. Flower is the reproductive organ of flowering plants.

  2. Stamen is the male reproductive part.

  3. Pistil (carpel) is the female reproductive part.

  4. Anther produces pollen grains.

  5. Ovary contains ovules.

  6. Pollination is the transfer of pollen.

  7. Self-pollination occurs within the same flower or plant.

  8. Cross-pollination occurs between different plants of the same species.

  9. Wind is an agent of pollination.

  10. Insects are important pollinating agents.

  11. Birds and bats also act as pollinators.

  12. Fertilization is the fusion of male and female gametes.

  13. Zygote develops into an embryo.

  14. Ovule develops into a seed.

  15. Ovary develops into a fruit.

SEXUAL REPRODUCTION IN ANIMALS

  1. Fertilization may be internal or external.

  2. Humans have internal fertilization.

  3. Frogs generally have external fertilization.

  4. Fish commonly show external fertilization (many species).

  5. Mammals are generally viviparous.

  6. Most birds are oviparous.

  7. Reptiles are mostly oviparous, though some are viviparous.

  8. Embryo develops into a young organism.

  9. Placenta nourishes the developing embryo in mammals.

  10. The umbilical cord connects the fetus to the placenta.

HUMAN REPRODUCTIVE FACTS

  1. Testes produce sperm.

  2. Ovaries produce ova (eggs).

  3. Fertilization usually occurs in the fallopian tube.

  4. The uterus is the site of implantation and fetal development.

  5. Menstruation occurs if fertilization does not take place.

  6. Puberty marks reproductive maturity.

  7. Hormones regulate reproduction.

  8. Testosterone is the main male sex hormone.

  9. Estrogen is a major female sex hormone.

  10. Progesterone supports pregnancy.

IMPORTANT SCIENTISTS

  1. Gregor Mendel – Father of Genetics.

  2. Robert Hooke – Cell.

  3. Charles Darwin – Evolution by natural selection.

  4. Watson and Crick described the double-helix structure of DNA.

  5. Rosalind Franklin's X-ray diffraction work was crucial to understanding DNA structure.

IMPORTANT FACTS

  1. Pea plant scientific name – Pisum sativum.

  2. DNA is present mainly in the nucleus.

  3. Mitochondria also contain DNA.

  4. Chloroplasts also contain DNA.

  5. Traits are inherited through genes.

  6. Variation is essential for evolution.

  7. Sexual reproduction increases genetic diversity.

  8. Asexual reproduction is faster than sexual reproduction.

  9. Seed dispersal helps reduce competition among seedlings.

  10. Fruits protect seeds.

  11. Pollination precedes fertilization.

  12. Fertilization precedes seed formation.

  13. Embryo develops from the zygote.

  14. Cotyledons store food in many seeds.

  15. Seed germination requires water, oxygen and suitable temperature.

  16. Light is required for germination in some species but not all.

  17. Hybridization combines desirable traits.

  18. Dominant traits appear in the F₁ generation.

  19. Recessive traits reappear in the F₂ generation.

  20. Law of segregation is also called the law of purity of gametes.

  21. Alleles separate during meiosis.

  22. Crossing over occurs during meiosis.

  23. Meiosis produces genetic variation.

  24. Mitosis maintains chromosome number in body cells.

  25. Reproduction maintains continuity of species.

  26. DNA replication occurs before cell division.

  27. Mutation is a change in DNA sequence.

  28. Environment also influences phenotype.

  29. Genes interact to determine many traits.

  30. Incomplete dominance and codominance are exceptions to simple Mendelian inheritance.

  31. Blood group inheritance is an example involving multiple alleles and codominance (AB group).

  32. Rh factor is inherited genetically.

  33. Cloning produces genetically similar individuals.

  34. Tissue culture is used for rapid propagation of plants.

  35. Mendel's work laid the foundation of modern genetics.

IMPORTANT TABLE

Mendel's Seven Contrasting Characters

Dominant TraitRecessive Trait
TallDwarf
Round SeedWrinkled Seed
Yellow SeedGreen Seed
Purple FlowerWhite Flower
Green PodYellow Pod
Inflated PodConstricted Pod
Axial FlowerTerminal Flower

Types of Asexual Reproduction

MethodExample
Binary FissionAmoeba, Paramecium
Multiple FissionPlasmodium
BuddingHydra, Yeast
FragmentationSpirogyra
RegenerationPlanaria
Spore FormationRhizopus
Vegetative PropagationPotato, Ginger, Onion, Bryophyllum

PREVIOUS YEAR EXAM CONCEPTS

✔ Father of Genetics

✔ Mendel's pea plant

✔ Laws of inheritance

✔ Dominant and recessive traits

✔ Gene, DNA and chromosome

✔ Binary fission

✔ Budding

✔ Pollination

✔ Fertilization

✔ Vegetative propagation

✔ XX and XY chromosomes

✔ Human chromosome number

✔ Father determines sex of the child

VERY IMPORTANT FACTS

  • Father of Genetics → Gregor Mendel

  • Pea plant → Pisum sativum

  • Gene → Unit of heredity

  • DNA → Genetic material

  • Chromosomes → Carry genes

  • Law of Dominance → Dominant trait expressed in F₁

  • Law of Segregation → Alleles separate during gamete formation

  • Binary fission → Amoeba

  • Budding → Hydra, Yeast

  • Fragmentation → Spirogyra

  • Spore formation → Rhizopus

  • Flower → Reproductive organ of angiosperms

  • Stamen → Male part

  • Pistil (Carpel) → Female part

  • Father (XY) determines the sex of the child

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Gregor Mendel is known as the Father of Genetics.

  2. Mendel conducted experiments on pea plants.

  3. F₁ generation expressed dominant traits.

  4. Genes are located on chromosomes.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q2. Which of the following statements are correct?

  1. Binary fission occurs in Amoeba.

  2. Budding occurs in Hydra.

  3. Fragmentation occurs in Spirogyra.

  4. Spore formation occurs in Rhizopus.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q3. Which statements are correct?

  1. Stamen is the male reproductive part of a flower.

  2. Pistil is the female reproductive part.

  3. Pollination occurs before fertilization.

  4. Ovary develops into a fruit after fertilization.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q4. Which of the following statements are correct?

  1. Humans have 46 chromosomes in somatic cells.

  2. Human gametes contain 23 chromosomes.

  3. XX represents female.

  4. XY represents male.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Consider the following statements:

  1. Vegetative propagation occurs in potato.

  2. Bryophyllum reproduces through leaf buds.

  3. Ginger reproduces by rhizome.

  4. Onion reproduces by bulb.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

PRACTICE MCQs

1. Who is known as the Father of Genetics?
A. Charles Darwin
B. Gregor Mendel
C. Robert Hooke
D. Linnaeus
Answer: B

2. The unit of heredity is:
A. Chromosome
B. DNA
C. Gene
D. Nucleus
Answer: C

3. Which type of reproduction occurs in Hydra?
A. Binary fission
B. Budding
C. Fragmentation
D. Regeneration
Answer: B

4. The male reproductive part of a flower is:
A. Pistil
B. Ovule
C. Stamen
D. Ovary
Answer: C

5. Which chromosome combination represents a human male?
A. XX
B. XO
C. XY
D. YY
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Gregor Mendel → Father of Genetics
Pisum sativum → Pea plant
Gene → Unit of heredity
DNA → Genetic material
46 chromosomes → Human somatic cells
23 chromosomes → Human gametes
XX = Female, XY = Male
Father determines child's sex
Law of Dominance → Dominant trait in F₁
Law of Segregation → Alleles separate during gamete formation
Binary fission → Amoeba
Budding → Hydra, Yeast
Fragmentation → Spirogyra
Spore formation → Rhizopus
Vegetative propagation → Potato, Ginger, Onion, Bryophyllum
Stamen → Male part
Pistil (Carpel) → Female part

Pollination → Fertilization → Seed → Fruit

CHAPTER 12 : CLASSIFICATION OF PLANTS AND ANIMALS (JKSSB General Science)

JKSSB Exam Weightage

Frequently Asked Topics

  • Taxonomy & Classification

  • Linnaeus and Binomial Nomenclature

  • Five Kingdom Classification

  • Classification of Plants

  • Classification of Animals

  • Vertebrates and Invertebrates

  • Characteristics of Major Plant Groups

  • Characteristics of Animal Phyla

  • Examples of Each Group

  • Scientific Names (Frequently Asked)

QUICK REVISION (170+ One-Liner Points)

CLASSIFICATION

  1. Classification is the systematic grouping of organisms.

  2. Taxonomy is the science of identification, naming and classification.

  3. Carolus Linnaeus is called the Father of Taxonomy.

  4. Linnaeus introduced Binomial Nomenclature.

  5. Every scientific name has two words.

  6. The first word is the Genus.

  7. The second word is the species (specific epithet).

  8. Genus starts with a capital letter.

  9. Species name starts with a small letter.

  10. Scientific names are written in italics (or underlined separately when handwritten).

FIVE KINGDOM CLASSIFICATION

  1. Proposed by R. H. Whittaker (1969).

  2. Kingdom Monera contains prokaryotes.

  3. Kingdom Protista contains mostly unicellular eukaryotes.

  4. Kingdom Fungi contains heterotrophic organisms with chitinous cell walls.

  5. Kingdom Plantae contains multicellular autotrophs.

  6. Kingdom Animalia contains multicellular heterotrophs.

  7. Viruses are acellular and are not placed in the five-kingdom system.

  8. Cyanobacteria belong to Monera.

  9. Amoeba belongs to Protista.

  10. Mushroom belongs to Fungi.

CLASSIFICATION OF PLANTS

Thallophyta (Algae)

  1. Simplest plants.

  2. Plant body is not differentiated into root, stem and leaves.

  3. Mostly aquatic.

  4. Reproduce mainly by spores.

  5. Example – Spirogyra.

  6. Example – Chlamydomonas.

  7. Example – Ulothrix.

Bryophyta

  1. Called amphibians of the plant kingdom.

  2. Grow in moist places.

  3. Lack true vascular tissues.

  4. Rhizoids are present instead of true roots.

  5. Mosses belong to Bryophyta.

  6. Liverworts belong to Bryophyta.

  7. Example – Funaria.

  8. Example – Marchantia.

Pteridophyta

  1. First vascular plants.

  2. True roots, stems and leaves are present.

  3. Reproduce by spores.

  4. No flowers or seeds.

  5. Fern is a pteridophyte.

  6. Example – Pteris.

  7. Example – Selaginella.

Gymnosperms

  1. Gymnosperms produce naked seeds.

  2. Seeds are not enclosed by fruits.

  3. Mostly evergreen.

  4. Cone-bearing plants.

  5. Pine is a gymnosperm.

  6. Cycas is a gymnosperm.

  7. Cedrus (Deodar) is a gymnosperm.

  8. Pollination is mainly by wind.

Angiosperms

  1. Angiosperms are flowering plants.

  2. Seeds are enclosed within fruits.

  3. Largest group of plants.

  4. Monocots have one cotyledon.

  5. Dicots have two cotyledons.

  6. Wheat is a monocot.

  7. Rice is a monocot.

  8. Maize is a monocot.

  9. Mango is a dicot.

  10. Pea is a dicot.

  11. Mustard is a dicot.

  12. Double fertilization is characteristic of angiosperms.

IMPORTANT TABLE

Classification of Plants

GroupVascular TissueSeedFlowerExample
ThallophytaNoNoNoSpirogyra
BryophytaNoNoNoFunaria
PteridophytaYesNoNoFern
GymnospermsYesYes (Naked)NoPine
AngiospermsYesYes (Covered)YesMango

CLASSIFICATION OF ANIMALS

Invertebrates

  1. Invertebrates lack a vertebral column.

  2. They constitute the majority of animal species.

Porifera

  1. Simplest multicellular animals.

  2. Body has pores.

  3. Mostly marine.

  4. Canal system present.

  5. Example – Sycon.

  6. Example – Spongilla.

Cnidaria (Coelenterata)

  1. Aquatic animals.

  2. Radial symmetry.

  3. Cnidoblasts (stinging cells) are present.

  4. Hydra belongs to Cnidaria.

  5. Jellyfish belongs to Cnidaria.

  6. Sea anemone belongs to Cnidaria.

Platyhelminthes

  1. Flatworms.

  2. Bilateral symmetry.

  3. Mostly parasites.

  4. Taenia (tapeworm).

  5. Planaria.

Nematoda

  1. Roundworms.

  2. Cylindrical body.

  3. Ascaris is a roundworm.

  4. Wuchereria causes filariasis.

Annelida

  1. Segmented worms.

  2. Closed circulatory system.

  3. Earthworm belongs to Annelida.

  4. Leech belongs to Annelida.

  5. Nereis belongs to Annelida.

Arthropoda

  1. Largest animal phylum.

  2. Jointed appendages.

  3. Chitinous exoskeleton.

  4. Cockroach belongs to Arthropoda.

  5. Housefly belongs to Arthropoda.

  6. Butterfly belongs to Arthropoda.

  7. Spider belongs to Arthropoda.

  8. Prawn belongs to Arthropoda.

Mollusca

  1. Soft-bodied animals.

  2. Muscular foot present.

  3. Shell usually present.

  4. Snail belongs to Mollusca.

  5. Octopus belongs to Mollusca.

  6. Oyster belongs to Mollusca.

Echinodermata

  1. Marine animals.

  2. Spiny skin.

  3. Water vascular system present.

  4. Starfish belongs to Echinodermata.

  5. Sea urchin belongs to Echinodermata.

Vertebrates (Phylum Chordata)

  1. Vertebrates possess a backbone.

  2. Notochord is present at least during development.

  3. Closed circulatory system.

  4. Well-developed brain.

Pisces

  1. Fishes belong to Pisces.

  2. Aquatic vertebrates.

  3. Gills for respiration.

  4. Fins for locomotion.

  5. Heart has two chambers.

  6. Rohu is a fish.

  7. Shark is a fish.

Amphibia

  1. Live on land and in water.

  2. Frog is an amphibian.

  3. Toad is an amphibian.

  4. Moist skin.

  5. Heart has three chambers.

Reptilia

  1. Dry scaly skin.

  2. Mostly lay eggs.

  3. Snake is a reptile.

  4. Lizard is a reptile.

  5. Crocodile is a reptile.

  6. Turtle is a reptile.

  7. Heart generally has three chambers; crocodiles have four.

Aves

  1. Birds belong to Aves.

  2. Feathers are present.

  3. Forelimbs modified into wings.

  4. Warm-blooded.

  5. Four-chambered heart.

  6. Pigeon belongs to Aves.

  7. Peacock belongs to Aves.

  8. Ostrich is the largest living bird.

Mammalia

  1. Mammals possess mammary glands.

  2. Hair is present.

  3. Warm-blooded animals.

  4. Four-chambered heart.

  5. Humans belong to Mammalia.

  6. Whale is a mammal.

  7. Bat is a mammal.

  8. Dolphin is a mammal.

  9. Platypus is an egg-laying mammal (monotreme).

  10. Blue whale is the largest living animal.

IMPORTANT SCIENTIFIC NAMES

Common NameScientific Name
HumanHomo sapiens
MangoMangifera indica
RiceOryza sativa
WheatTriticum aestivum
PeaPisum sativum
House CrowCorvus splendens
TigerPanthera tigris
LionPanthera leo
DogCanis lupus familiaris
CatFelis catus
BanyanFicus benghalensis
NeemAzadirachta indica

IMPORTANT FACTS

  1. Father of Taxonomy – Carolus Linnaeus.

  2. Five Kingdom Classification – R. H. Whittaker.

  3. Arthropoda is the largest animal phylum.

  4. Angiosperms are the largest plant group.

  5. Bryophytes are called amphibians of the plant kingdom.

  6. Pteridophytes are the first vascular plants.

  7. Gymnosperms have naked seeds.

  8. Angiosperms have covered seeds.

  9. Fish have a two-chambered heart.

  10. Amphibians have a three-chambered heart.

  11. Reptiles generally have a three-chambered heart.

  12. Birds have a four-chambered heart.

  13. Mammals have a four-chambered heart.

  14. Crocodile has a four-chambered heart.

  15. Bat is the only true flying mammal.

  16. Whale is the largest mammal.

  17. Blue whale is the largest animal on Earth.

  18. Ostrich is the largest living bird.

  19. Peacock is the national bird of India.

  20. Tiger is the national animal of India.

PREVIOUS YEAR EXAM CONCEPTS

✔ Father of Taxonomy

✔ Five Kingdom Classification

✔ Binomial Nomenclature

✔ Bryophytes

✔ Gymnosperms

✔ Angiosperms

✔ Arthropoda

✔ Amphibians

✔ Mammals

✔ Scientific names

✔ Chambered hearts

✔ Vertebrates vs Invertebrates

VERY IMPORTANT FACTS

Carolus Linnaeus → Father of Taxonomy
R. H. Whittaker → Five Kingdom Classification
Arthropoda → Largest animal phylum
Angiosperms → Largest plant group
Bryophytes → Amphibians of the plant kingdom
Pteridophytes → First vascular plants
Gymnosperms → Naked seeds
Angiosperms → Covered seeds
Fish → 2-chambered heart
Amphibians → 3-chambered heart
Birds & Mammals → 4-chambered heart
Crocodile → 4-chambered heart
Bat → Flying mammal

Blue whale → Largest animal

STATEMENT-TYPE MCQs (One or More Options Correct)

Q1. Consider the following statements:

  1. Carolus Linnaeus introduced binomial nomenclature.

  2. R. H. Whittaker proposed the five-kingdom classification.

  3. Viruses are placed in Kingdom Monera.

  4. Scientific names consist of genus and species.

A. 1, 2 and 4 only
B. 1 and 3 only
C. 2 and 3 only
D. All are correct

Answer: A

Q2. Which of the following statements are correct?

  1. Bryophytes are called amphibians of the plant kingdom.

  2. Pteridophytes are the first vascular plants.

  3. Gymnosperms have naked seeds.

  4. Angiosperms produce flowers.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q3. Which statements are correct?

  1. Arthropoda is the largest animal phylum.

  2. Earthworm belongs to Annelida.

  3. Hydra belongs to Cnidaria.

  4. Snail belongs to Mollusca.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q4. Which of the following statements are correct?

  1. Fish have a two-chambered heart.

  2. Amphibians have a three-chambered heart.

  3. Birds have a four-chambered heart.

  4. Mammals have a four-chambered heart.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

Q5. Consider the following statements:

  1. Whale is a mammal.

  2. Bat is the only true flying mammal.

  3. Crocodile has a four-chambered heart.

  4. Blue whale is the largest living animal.

A. 1, 2, 3 and 4
B. 1 and 2 only
C. 2 and 3 only
D. 1, 3 and 4 only

Answer: A

PRACTICE MCQs

1. Who is known as the Father of Taxonomy?
A. Charles Darwin
B. Gregor Mendel
C. Carolus Linnaeus
D. R. H. Whittaker
Answer: C

2. Which plant group has naked seeds?
A. Bryophyta
B. Pteridophyta
C. Gymnosperms
D. Angiosperms
Answer: C

3. Which is the largest animal phylum?
A. Mollusca
B. Annelida
C. Arthropoda
D. Chordata
Answer: C

4. Which animal has a four-chambered heart among reptiles?
A. Snake
B. Lizard
C. Crocodile
D. Turtle
Answer: C

5. The scientific name of humans is:
A. Panthera tigris
B. Canis lupus familiaris
C. Homo sapiens
D. Mangifera indica
Answer: C

JKSSB Last-Minute Revision (10 Seconds Before Exam)

Carolus Linnaeus → Father of Taxonomy
R. H. Whittaker → Five Kingdom Classification
Monera → Prokaryotes
Protista → Unicellular eukaryotes
Fungi → Chitin cell wall
Plantae → Autotrophs
Animalia → Heterotrophs
Bryophytes → Amphibians of plant kingdom
Pteridophytes → First vascular plants
Gymnosperms → Naked seeds
Angiosperms → Covered seeds & flowers
Arthropoda → Largest animal phylum
Fish → 2-chambered heart
Amphibians → 3-chambered heart
Reptiles → Mostly 3 chambers (Crocodile = 4)
Birds & Mammals → 4-chambered heart
Homo sapiens → Human
Pisum sativum → Pea
Mangifera indica → Mango

Oryza sativa → Rice

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Home academy is JK's First e-learning platform started by Er. Afzal Malik For Competitive examination and Academics K12. We have true desire to serve to society by way of making educational content easy . We are expertise in STEM We conduct workshops in schools Deals with Science Engineering Projects . We also Write Thesis for your Research Work in Physics Chemistry Biology Mechanical engineering Robotics Nanotechnology Material Science Industrial Engineering Spectroscopy Automotive technology ,We write Content For Coaching Centers also infohomeacademy786@gmail.com

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