Hard Set - Synthesis & NEET Traps
Revise these high-yield discriminators before attempting the set.
Modification traps (very frequently tested):
- Tendril: grapevine/cucumber/pumpkin = stem tendril (axillary bud); pea = leaf tendril. Watch this.
- Thorn (Citrus, Bougainvillea) = stem/axillary; spine (Opuntia) = leaf. Phylloclade (Opuntia) = flattened green stem.
- Potato = stem tuber (eyes are axillary buds); sweet potato = root. Onion = stem (bulb); its fleshy scales are leaves.
- Pneumatophores = Rhizophora (respiration); prop roots = banyan; stilt roots = maize/sugarcane.
Flower: actinomorphic (mustard, Datura, chilli) vs zygomorphic (pea, gulmohur, Cassia, bean). Ovary: hypogynous = superior, perigynous = half-inferior (rose, plum, peach), epigynous = inferior (guava, cucumber, sunflower ray florets).
Aestivation: valvate (Calotropis), twisted (china rose, cotton, lady's finger), imbricate (Cassia, gulmohur), vexillary (pea, bean).
Stamen cohesion: monadelphous (china rose), diadelphous (pea), polyadelphous (Citrus), syngenesious anthers (sunflower). Epipetalous = brinjal.
Placentation: marginal (pea), axile (china rose, tomato, lemon), parietal (mustard, Argemone), free central (Dianthus, Primrose), basal (sunflower, marigold).
Families: Fabaceae = zygomorphic, vexillary, diadelphous (9+1), marginal, legume. Solanaceae = actinomorphic, epipetalous (5), axile, berry. Liliaceae = trimerous, perianth 6, axile.
Assertion-Reason key: (a) Both true, R correct explanation; (b) Both true, R NOT explanation; (c) A true, R false; (d) A false, R true.