AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
The thick, spongy lining of the uterus is shed as blood and mucus during menstruation because the egg is not fertilised and the lining is no longer needed.
Source: Chapter 7, Section 7.3.3(c)
The answer must include two parts: what is shed (uterine lining/blood and mucus) and why (egg not fertilised, so the prepared lining breaks down). Examiners expect both for the 1 mark.