📑 Topics on this page (Jump to Topic):
📌 1. Basics of Classification
- Carolus Linnaeus — "father of taxonomy"; binomial nomenclature (1753, Species Plantarum): first word genus (capitalised), second species. E.g. human — Homo sapiens.
- Hierarchy: Kingdom → Phylum/Division → Class → Order → Family → Genus → Species. Species is the basic unit of classification.
- R. H. Whittaker (1969) — five kingdoms: Monera, Protista, Fungi, Plantae, Animalia.
| Kingdom | Key features / examples |
|---|---|
| Monera | Prokaryotic; bacteria, blue-green algae (cyanobacteria) |
| Protista | Unicellular eukaryotes; Amoeba, Paramecium, Euglena, Plasmodium |
| Fungi | Heterotrophic/saprophytic, chitin wall; yeast, mushroom, Penicillium |
| Plantae | Multicellular autotrophs, cellulose wall |
| Animalia | Multicellular heterotrophs, no cell wall |
- Virus — link between living and non-living; multiplies only inside living cells; protein coat + DNA or RNA (never both). Discovered by Ivanovsky (1892, tobacco mosaic); named "virus" by Beijerinck. A bacteriophage infects bacteria.
- Lichen — symbiosis of an alga and a fungus; indicator of air pollution (SO₂).
📌 2. Plant Kingdom
| Group | Features / examples |
|---|---|
| Thallophyta (algae) | Body not differentiated into root-stem-leaf; Spirogyra, Chlamydomonas |
| Bryophyta | "Amphibians of the plant kingdom"; no vascular tissue; moss, Marchantia |
| Pteridophyta | First plants with vascular tissue, no seeds; ferns, Marsilea |
| Gymnosperms | Naked seeds, no fruit; pine, deodar, Cycas |
| Angiosperms | Seeds inside fruit; monocots (wheat, maize) and dicots (gram, mango) |
- Tallest gymnosperm — Sequoia (redwood); smallest angiosperm — Wolffia.
📌 3. Animal Kingdom
| Phylum / class | Examples |
|---|---|
| Porifera | Sponges (porous body) |
| Coelenterata (Cnidaria) | Hydra, jellyfish, sea anemone, coral |
| Platyhelminthes | Flatworms — tapeworm, liver fluke, Planaria |
| Aschelminthes (Nematoda) | Roundworms — Ascaris, filarial worm |
| Annelida | Segmented body — earthworm, leech, Nereis |
| Arthropoda | Largest phylum; jointed legs — insects, prawn, spider, scorpion |
| Mollusca | Soft body, shell — snail, oyster, octopus |
| Echinodermata | Spiny skin, marine — starfish, sea urchin |
| Chordata | Fishes, amphibians, reptiles, birds, mammals |
- Not fish: starfish, jellyfish, silverfish, cuttlefish; a fish: sea horse. Whale, dolphin, bat are mammals; egg-laying mammals — platypus, echidna.
⚠️ Exam Traps:
- A virus has either DNA or RNA, never both.
- Bryophytes are the "amphibians"; pteridophytes are the first vascular plants.
- Mushroom is a fungus, not a plant.
📌 4. Practice MCQs
📝 Practice MCQs (prepared by SF Prep — not PYQs)
Q1. Binomial nomenclature was given by: Practice
Correct answer: (B)
In 1753 in Species Plantarum.
In 1753 in Species Plantarum.
Q2. The five-kingdom classification was proposed by: Practice
Correct answer: (D)
In 1969.
In 1969.
Q3. The basic unit of classification is: Practice
Correct answer: (A)
A group of similar organisms that can interbreed.
A group of similar organisms that can interbreed.
Q4. The scientific name of humans is: Practice
Correct answer: (A)
Homo — genus, sapiens — species.
Homo — genus, sapiens — species.
Q5. Bacteria belong to the kingdom: Practice
Correct answer: (C)
Prokaryotic organisms.
Prokaryotic organisms.
Q6. Amoeba and Paramecium belong to: Practice
Correct answer: (B)
Unicellular eukaryotes.
Unicellular eukaryotes.
Q7. A mushroom is a: Practice
Correct answer: (A)
Saprophytic; chitin cell wall.
Saprophytic; chitin cell wall.
Q8. Viruses were discovered by: Practice
Correct answer: (A)
In 1892 from tobacco mosaic disease.
In 1892 from tobacco mosaic disease.
Q9. The link between living and non-living is: Practice
Correct answer: (D)
Inert, crystal-like outside a cell.
Inert, crystal-like outside a cell.
Q10. A lichen is a symbiotic association of: Practice
Correct answer: (C)
Indicators of air pollution.
Indicators of air pollution.
Q11. The "amphibians of the plant kingdom" are: Practice
Correct answer: (B)
Need water to complete the life cycle.
Need water to complete the life cycle.
Q12. The first plants with vascular tissue (seedless) are: Practice
Correct answer: (D)
E.g. ferns.
E.g. ferns.
Q13. Plants with naked seeds are called: Practice
Correct answer: (C)
No fruit forms; pine, Cycas.
No fruit forms; pine, Cycas.
Q14. The largest animal phylum is: Practice
Correct answer: (B)
Includes insects — most known animals.
Includes insects — most known animals.
Q15. The earthworm belongs to the phylum: Practice
Correct answer: (C)
Segmented worms.
Segmented worms.
Q16. Which of these is actually a fish? Practice
Correct answer: (D)
Starfish is an echinoderm, jellyfish a coelenterate, silverfish an insect.
Starfish is an echinoderm, jellyfish a coelenterate, silverfish an insect.
Q17. An egg-laying mammal is the: Practice
Correct answer: (A)
The echidna also lays eggs.
The echidna also lays eggs.
Q18. Hydra belongs to: Practice
Correct answer: (B)
Jellyfish and corals too.
Jellyfish and corals too.
Q19. The tapeworm belongs to: Practice
Correct answer: (D)
Flatworm; Ascaris is a roundworm (Nematoda).
Flatworm; Ascaris is a roundworm (Nematoda).
Q20. The smallest flowering plant is: Practice
Correct answer: (C)
Tallest gymnosperm — Sequoia.
Tallest gymnosperm — Sequoia.