Generated by claude-sonnet-4-6 · 2026-06-15 06:47 · grounding rag
Model Answer
(a) In Amoeba, binary fission can occur in any plane (irregular). In Leishmania, binary fission occurs in a definite plane — always longitudinally — because it has a whip-like flagellum whose position determines the plane of division.
(b) The malarial parasite (Plasmodium) reproduces by multiple fission — the nucleus divides many times and then the cytoplasm divides to form many daughter cells simultaneously.
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Explanation
- (a) The key distinction is plane of division: Amoeba — no fixed plane; Leishmania — fixed longitudinal plane due to flagellum. Examinees often lose marks by not mentioning the reason (flagellum) or the plane.
- (b) "Multiple fission" is the exact term needed. The passage (Fig. 7.2 caption) names it for Plasmodium. Writing "binary fission" here is wrong and will cost the mark.