Classification of Living Organisms
PART-A Unit-I: General Science
Previous Year Questions (PYQ) for this topic
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Biology - Important Notes - PYQ Points
• Father of Zoology: Aristotle.
• Father of Paleobotany: Birbal Sahni (Indian scientist).
• Father of Paleobotany: Birbal Sahni (Indian scientist).
1. Taxonomy
- Kingdoms: Prokaryotes belong to the Monera kingdom, while unicellular eukaryotes belong to the Protista kingdom.
- System: Carolus Linnaeus proposed the "Artificial System" of classification. The currently used system is the "Natural System" of classification.
- Hierarchy: The lowest unit of classification is the Species.
2. Botany
Plant Groups:
- Bryophytes: Prevent soil erosion. Sphagnum absorbs large amounts of water and is used to obtain 'peat' fuel.
- Pteridophytes: Called "vascular cryptogams".
- Gymnosperms: These are naked seed plants (e.g., Sequoia – the tallest tree).
Plant Hormones & Chemistry:
| Factor/Hormone | Function/Use |
|---|---|
| Auxin | Apical dominance. |
| Gibberellin | Increases amylase activity. |
| Ethylene | Ripens fruits. |
| Florigen | Stimulates flower production. |
| Anthocyanin | Responsible for the color of apple and tomato skin. |
Nutrient Deficiency Diseases:
- Copper: Causes Exanthema disease in citrus plants.
- Zinc: Causes little leaf disease.
- Potassium: Causes scorching of leaf
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