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Science (086) — AI-generated practice question

AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.

Q1. [1] medium thorough-understanding
Sexual reproduction combines variations from two parents rather than creating new mutations. Which of the following best explains why this makes sexual reproduction less risky for individual survival than relying on random DNA-copying errors for variation? (A) Variations already tested in parents are less likely to be lethal than brand-new random mutations. (B) Sexual reproduction always produces more offspring than asexual reproduction. (C) Gametes formed by meiosis never carry copying errors. (D) Combining two genomes eliminates all harmful variations from both parents.
  1. A Two individuals always carry identical variations, so there is no risk of incompatibility.
  2. B Because both individuals are already alive, their accumulated variations are known not to be fatally harmful.
  3. C Sexual reproduction eliminates all harmful mutations before they are passed on.
  4. D The process of meiosis corrects any dangerous DNA errors before fusion of germ-cells.
Generated by claude-sonnet-4-6 · 2026-06-26 01:05 · grounding rag
Model Answer

Answer: (B) — Because both individuals are already alive, their accumulated variations are known not to be fatally harmful.

Explanation

The passage explicitly states: "Since all of these variations are in living individuals, it is assured that they do not have any really bad effects." This means variations inherited through sexual reproduction have already been 'tested' for survival — the parents are alive, proving their variations aren't lethal. Random new mutations, however, are untested and may be fatal. Option (B) directly mirrors this textbook reasoning. Options (C) and (D) are factually incorrect; meiosis does not eliminate copying errors, nor does sexual reproduction remove all harmful mutations.

Source: Chapter 7, Section 7.3.1 — Why the Sexual Mode of Reproduction?

Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.