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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
[mcq] A forest contains two populations of beetles — Population X, in which all individuals are identical, and Population Y, which shows considerable variation in body colour and heat tolerance. If a sudden drought raises the forest temperature significantly, which of the following most accurately predicts the outcome and explains why? (A) Population X will survive better because all its members share the same successful traits. (B) Population Y will survive better because some individuals may already possess traits suited to the new conditions. (C) Both populations will be equally affected because survival depends only on population size. (D) Population X will survive better because identical DNA is copied with fewer errors during reproduction.
  1. A Organisms without variation reproduce more slowly, reducing population size over time.
  2. B If the environment changes, no individual in the population would have traits suited to the new conditions.
  3. C A uniform population consumes resources faster and is more likely to face starvation.
  4. D Without variation, organisms cannot carry out DNA copying and reproduction stops entirely.
Generated by claude-sonnet-4-6 · 2026-06-26 01:04 · grounding rag
Model Answer

The correct answer to the MCQ is (B).

The correct option is (B) — If the environment changes, no individual in the population (X) would have traits suited to the new conditions.

Population Y survives better because some individuals already possess heat-tolerant traits; Population X, being uniform, has no such variants to withstand the changed conditions.

Explanation

The passage from Section 7.1.1 directly states: "if some variations were to be present in a few individuals, there would be some chance for them to survive" — using the exact example of bacteria and rising temperature. Population X (no variation) has no individual suited to drought/heat, so the entire group is at risk. The MCQ answer is (B), and among the four options given for the follow-up, Option B correctly identifies why uniformity is dangerous: no individual in the population has traits suited to the changed environment. Examiners want students to link variation → survival advantage using the textbook example.

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