Observe the given diagram and answer the questions that follow :
(i) Give the name of the structure and type of reproduction shown in the above diagram.
(ii) State one advantage and one disadvantage of the above mentioned method of reproduction.
(iii) Give reason : Asexual reproduction lacks genetic variation.
(iv) Why have higher organisms resorted to sexual reproduction in spite of its complexity ?
Generated by claude-sonnet-4-6 · 2026-06-15 06:42 · grounding rag
Model Answer
(i) The diagram shows spore formation in Rhizopus (bread mould). The blob-on-a-stick structures are sporangia containing spores. This is a method of asexual reproduction.
(ii)
- Advantage: Spores are covered by thick walls, protecting them under unfavourable conditions; they can grow rapidly when conditions become suitable.
- Disadvantage: No genetic variation is produced, so the population may be wiped out if environmental conditions change drastically.
(iii) In asexual reproduction, a new individual is created from a single parent through DNA copying. Since only one organism is involved and no mixing of genetic material occurs, all offspring are genetically identical to the parent, resulting in no variation.
(iv) Despite its complexity, sexual reproduction produces genetic variations by combining DNA from two individuals. These variations help the species adapt to changing environments and ensure long-term survival of the population.
Source: Chapter 7 — Reproduction, Sections 7.2.6, 7.1.1, 7.3
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Explanation
- The diagram almost certainly shows Rhizopus spore formation (the classic asexual reproduction diagram in the NCERT chapter). Name it correctly.
- For part (ii), examiners expect one advantage and one disadvantage — keep each to one sentence.
- For part (iii), the key phrase is "single parent + DNA copying = identical offspring = no variation." Mention all three links.
- For part (iv), the core answer from the textbook is: sexual reproduction allows greater variation, aiding species survival — state this clearly. Avoid vague answers like "it is better."