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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 exam-ready
Menstruation occurs approximately every month. Which of the following correctly describes why the uterine lining breaks down during menstruation? (A) The ovary releases too many eggs at once (B) Fertilisation has occurred and the embryo rejects the lining (C) The egg has not been fertilised, so the thickened uterine lining is no longer needed (D) Hormones from the placenta cause the lining to shed
  1. A The ovary releases too many eggs at once
  2. B Fertilisation has occurred and the embryo rejects the lining
  3. C The egg has not been fertilised, so the thickened uterine lining is no longer needed
  4. D Hormones from the placenta cause the lining to shed
Generated by claude-sonnet-4-6 · 2026-06-26 01:00 · grounding rag
Model Answer

(C) The egg has not been fertilised, so the thickened uterine lining is no longer needed and it breaks down, coming out as blood and mucus — this is menstruation.

Source: Chapter 7, Section 7.3.3(c)

Explanation

The passage clearly states that the uterine lining thickens each month to nourish a potential embryo. If fertilisation does not occur, the lining is "not needed any longer" and breaks down. Options A, B, and D are factually incorrect — the placenta only forms after fertilisation, and only one egg is released per month.

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