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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. [2] medium exam-ready
Why does a germ cell contain only one set of genes while all other body cells contain two sets?
Generated by claude-sonnet-4-6 · 2026-06-26 01:03 · grounding rag
Model Answer

Germ cells are produced by a special cell division called meiosis, which halves the number of chromosomes (and DNA content). This is necessary because when two germ cells combine during fertilisation, the normal chromosome number is restored in the new individual. If germ cells had two sets, the zygote would have double the DNA of normal body cells, disrupting cellular control.

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

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Explanation

The key concept here is meiosis — the examiner expects you to name it and explain why it happens (to prevent doubling of chromosomes at fertilisation). Two marks = name the process + give the reason. Avoid writing a long paragraph; two crisp sentences covering both points earn full marks.

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