Answer the following:
(i) Name and explain the two modes of asexual reproduction observed in hydra.
(ii) What is vegetative propagation ? List two advantages of using this technique.
Generated by claude-sonnet-4-6 · 2026-06-15 06:43 · grounding rag
Model Answer
(i) Two modes of asexual reproduction in Hydra:
1. Budding: In Hydra, a bud develops as an outgrowth due to repeated cell division at one specific site. The bud gradually develops into a tiny individual and, when fully mature, detaches from the parent body to become a new independent organism.
2. Regeneration: If a Hydra is broken into pieces, each piece can regenerate into a complete new individual using specialised regenerative cells.
(ii) Vegetative Propagation:
It is a mode of asexual reproduction in which parts like roots, stems, or leaves of a plant develop into new plants under suitable conditions.
Two advantages:
- Plants raised by vegetative propagation bear flowers and fruits earlier than those grown from seeds.
- All plants produced are genetically identical to the parent, retaining all its desirable characteristics.
Source: Chapter 7, Sections 7.2.4 and 7.2.5
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Explanation
- The question is 5 marks: allocate roughly 2 marks to (i) and 3 marks to (ii).
- For (i), examiners expect both budding and regeneration named and briefly explained — Hydra's "What you have learnt" summary confirms both modes.
- For (ii), define vegetative propagation first, then list exactly two advantages from the textbook passage (early flowering/fruiting; genetic similarity). Don't add extra points — it wastes time and gains nothing.
- Always name and explain in budding answers; just naming alone may cost you a mark.