HOME ACADEMY NOTES
Classification of Plants (science)
Complete Notes for Competitive Examinations (JKSSB, SSC, UPSC, PSC, CUET, NEET, Banking & Other Exams)
Classification of Plants
Introduction
Plants are living organisms belonging to Kingdom Plantae. They are multicellular, eukaryotic organisms that contain chlorophyll and prepare their own food through photosynthesis.
Plant classification (Plant Taxonomy) is the scientific arrangement of plants into groups based on their similarities and differences.
Father of Taxonomy: Carolus Linnaeus
Branch of Biology dealing with plant classification: Taxonomy
Need for Classification
Classification helps to:
Identify plants correctly.
Study similarities and differences.Understand evolutionary relationships.
Make scientific naming easier.
Facilitate research and conservation.
Complete Classification of Kingdom Plantae
Kingdom Plantae
│
├── Cryptogams (Non-Flowering Plants)
│
│ ├── Thallophyta
│ ├── Bryophyta
│ └── Pteridophyta
│
└── Phanerogams (Seed Producing Plants)
│
├── Gymnosperms
└── Angiosperms
│
├── Monocotyledons
└── Dicotyledons
Division 1: Cryptogams
Meaning
The word Cryptogam means Hidden Reproduction.
These plants do not produce flowers, fruits or seeds.
They reproduce through spores.
Characteristics
Seedless
FlowerlessMostly grow in moist places
Reproduce by spores
Divisions
Thallophyta
BryophytaPteridophyta
1. Thallophyta (Algae)
Meaning
Plants whose body is not differentiated into root, stem and leaves.
Body is called Thallus.
Characteristics
Simplest plants
Mostly aquatic
No vascular tissues
Reproduce by spores
Photosynthetic (except fungi in older classifications)
Examples
Spirogyra
Chlamydomonas
Ulothrix
Volvox
Chara
Importance
Produce oxygen
Used as food
Source of agar
Used in fertilizers
2. Bryophyta
Meaning
Bryophytes are called the Amphibians of the Plant Kingdom.
They require water for reproduction.
Characteristics
Small plants
No true roots, stem and leaves
Rhizoids present
No vascular tissues
Grow in moist places
Examples
Marchantia
Riccia
Funaria
Mosses
Importance
Prevent soil erosion
Form peat
Water conservation
3. Pteridophyta
Meaning
First vascular plants.
Called Vascular Cryptogams.
Characteristics
Root, stem and leaves present
Xylem and phloem present
Reproduce by spores
No flowers
No seeds
Examples
Fern
Selaginella
Lycopodium
Equisetum
Importance
Ornamental plants
Soil binding
Fossil fuel formation
Division 2: Phanerogams
Meaning
Plants having visible reproductive organs and seeds.
Characteristics
Seed producing
Well-developed vascular tissues
Root, stem and leaves well developed
Divisions
Gymnosperms
Angiosperms
4. Gymnosperms
Meaning
Gymnosperm means Naked Seed.
Seeds are not enclosed within fruits.
Characteristics
Woody plants
Evergreen
Cone-bearing plants
Wind pollinated
Naked seeds
Examples
Pinus
Cycas
Cedrus (Deodar)
Ginkgo
Importance
Timber
Paper industry
Medicines
Resins
5. Angiosperms
Meaning
Flowering plants.
Seeds enclosed inside fruits.
Largest group of plants.
Characteristics
Flowers present
Fruits present
Seeds enclosed in fruits
Double fertilization occurs (unique feature)
Examples
Mango
Wheat
Rice
Rose
Sunflower
Classification of Angiosperms
A. Monocotyledons (Monocots)
Characteristics
One cotyledon
Parallel venation
Fibrous roots
Floral parts in multiples of 3
Vascular bundles scattered
Examples
Rice
Wheat
Maize
Sugarcane
Bamboo
Coconut
B. Dicotyledons (Dicots)
Characteristics
Two cotyledonsReticulate venation
Tap root
Floral parts in multiples of 4 or 5
Vascular bundles arranged in a ring
Examples
Pea
Mustard
Mango
Rose
Sunflower
Cotton
Complete Comparison of Plant Groups
| Feature | Thallophyta | Bryophyta | Pteridophyta | Gymnosperm | Angiosperm |
|---|---|---|---|---|---|
| Roots | Absent | Rhizoids | Present | Present | Present |
| Stem | Absent | Simple | Present | Present | Present |
| Leaves | Absent | Simple | Present | Present | Present |
| Vascular Tissue | No | No | Yes | Yes | Yes |
| Flowers | No | No | No | No | Yes |
| Seeds | No | No | No | Yes | Yes |
| Fruits | No | No | No | No | Yes |
| Reproduction | Spores | Spores | Spores | Seeds | Seeds |
Monocot vs Dicot
| Character | Monocot | Dicot |
|---|---|---|
| Cotyledons | One | Two |
| Root | Fibrous | Tap |
| Leaf Venation | Parallel | Reticulate |
| Flower Parts | Multiple of 3 | Multiple of 4 or 5 |
| Vascular Bundles | Scattered | Ring |
| Secondary Growth | Usually absent | Usually present |
Important Scientific Facts
Largest plant group → Angiosperms
Simplest plants → Thallophyta
First land plants → Bryophytes
Amphibians of Plant Kingdom → Bryophytes
First vascular plants → Pteridophytes
Naked seeded plants → Gymnosperms
Flowering plants → Angiosperms
Double fertilization → Angiosperms only
Largest division of plants → Angiosperms
Previous Exam Facts
Pine belongs to Gymnosperm.
Moss belongs to Bryophyta.
Fern belongs to Pteridophyta.
Rice is a Monocot.
Mustard is a Dicot.
Cycas is a living fossil among Gymnosperms.
Double fertilization occurs only in Angiosperms.
Memory Trick
Order of Plant Classification
T → B → P → G → A
"Tall Boys Prefer Good Apples."
T = Thallophyta
B = Bryophyta
P = Pteridophyta
G = Gymnosperm
A = Angiosperm
Multiple Choice Questions (MCQs)
1. The simplest group of plants is:
A. Bryophyta
B. Pteridophyta
C. Thallophyta
D. Gymnosperms
Answer: C
2. Amphibians of the plant kingdom are:
A. Ferns
B. Mosses
C. Pine
D. Wheat
Answer: B
3. First vascular plants are:
A. Bryophytes
B. Gymnosperms
C. Pteridophytes
D. Angiosperms
Answer: C
4. Naked seeded plants are:
A. Angiosperms
B. Gymnosperms
C. Bryophytes
D. Mosses
Answer: B
5. Double fertilization occurs in:
A. Gymnosperms
B. Pteridophytes
C. Angiosperms
D. Bryophytes
Answer: C
6. Rice belongs to:
A. Dicot
B. Monocot
C. Gymnosperm
D. Bryophyte
Answer: B
7. Which is a Gymnosperm?
A. Mango
B. Rose
C. Pinus
D. Wheat
Answer: C
8. Moss belongs to:
A. Thallophyta
B. Bryophyta
C. Angiosperm
D. Gymnosperm
Answer: B
9. Which group reproduces by spores?
A. Gymnosperms only
B. Angiosperms only
C. Cryptogams
D. Phanerogams
Answer: C
10. Which plant has flowers?
A. Fern
B. Moss
C. Mango
D. Pinus
Answer: C
Statement-Based MCQs
Question 1
Statement I: Bryophytes are called amphibians of the plant kingdom.
Statement II: They require water for fertilization.
A. Both statements are true and II is the correct explanation of I.
B. Both are true but II is not the correct explanation.
C. I is true, II is false.
D. I is false, II is true.
Answer: A
Question 2
Statement I: Gymnosperms produce naked seeds.
Statement II: Their seeds are enclosed within fruits.
A. Both true
B. I true, II false
C. I false, II true
D. Both false
Answer: B
Question 3
Statement I: Angiosperms are flowering plants.
Statement II: Double fertilization is a unique feature of angiosperms.
A. Both true and II correctly explains I
B. Both true but II does not explain I
C. I true, II false
D. Both false
Answer: B
Question 4
Statement I: Pteridophytes possess vascular tissues.
Statement II: They reproduce through spores.
A. Both statements are true.
B. Only I is true.
C. Only II is true.
D. Both are false.
Answer: A
Question 5
Statement I: Monocots have one cotyledon.
Statement II: Monocots usually possess parallel leaf venation.
A. Both statements are true.
B. Only I is true.
C. Only II is true.
D. Both are false.
Answer: A
Question 6
Statement I: Dicot plants generally have tap roots.
Statement II: Their floral parts are usually in multiples of four or five.
A. Both statements are true.
B. Only I is true.
C. Only II is true.
D. Both are false.
Answer: A
One-Liner Revision
Kingdom of plants → Plantae
Non-seed plants → CryptogamsSeed plants → Phanerogams
Simplest plants → Thallophyta
Amphibians of plant kingdom → Bryophytes
First vascular plants → Pteridophytes
Naked seed plants → Gymnosperms
Flowering plants → Angiosperms
One cotyledon → Monocot
Two cotyledons → Dicot
Double fertilization → Angiosperms only
Fern → Pteridophyta
Moss → Bryophyta
Pinus → Gymnosperm
Rice and Wheat → Monocots
Pea and Mustard → Dicots