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UPPCS Biology Gap Sheet: Plant Physiology, Hormones and Crop Diseases.
UPPCS has asked 20 of these. 3 have not been asked yet. Lock the first list, then read the second: it holds what UPPCS has not used yet.
First, the concept
Water moves down a water-potential gradient, while sugars move from sources to sinks. Photosynthesis stores light energy; respiration releases usable energy and occurs in plants as well as animals.
Plant hormones regulate growth through balance, not one hormone per function. Crop damage may come from pathogens or nutrient deficiency; a deficiency disorder is not an infection.
✅ Already asked (20)
Transport and photosynthesis
- Root hairs · Increase absorbing surface in the root maturation zone.
- Transpiration pull · Water cohesion and leaf water loss help pull xylem water upward.
- Hydroponics · Plants grow without soil in a supplied nutrient solution.
- Chlorophyll magnesium · Magnesium is the central metal in chlorophyll.
- Light reaction · Thylakoids produce ATP and NADPH and release oxygen from water.
- C3 and C4 pathways · C3 first stable product has three carbons; C4 has four; maize and sugarcane are C4.
- CAM plants · Many succulents open stomata at night and conserve water.
- Plant respiration · Plants respire day and night; photosynthesis needs a suitable light source.
Growth signals
- Auxin · Supports elongation and apical dominance; involved in tropic responses.
- Gibberellins · Promote stem elongation and can help break seed dormancy.
- Cytokinins · Promote cell division and delay senescence in many tissues.
- Abscisic acid · Promotes dormancy and stomatal closure during water stress.
- Ethylene · Gaseous hormone promotes ripening; ethephon releases ethylene.
Nutrition and crop disorders
- Gypsum · Calcium sulphate supplies calcium and sulphur.
- Khaira and white bud · Zinc deficiency causes khaira in rice and white-bud symptoms in maize.
- Karnal bunt · Wheat fungal disease caused by Tilletia indica.
- Wheat rust · Puccinia fungi cause rust diseases, also called gerui.
- Potato late blight · Phytophthora infestans is an oomycete, not a true fungus.
- Okra yellow vein mosaic · Viral disease commonly transmitted by whiteflies.
- Rice false smut · Ustilaginoidea virens causes false smut of rice, not barley.
❌ Not asked yet (3)
🔒 3 items not asked yet
Transport and photosynthesis: 2 · Growth signals: 1
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⚠️ Photosynthetic oxygen comes from water. Khaira of rice is zinc deficiency, not a fungal infection.
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