# Life Sciences Paper 1, November 2024, question 3.4.1(c)

> The diagram below shows how the level of thyroxin in the blood is kept... Marked mark by mark. Q3.4.1(c), Life Sciences Paper 1 November 2024, 1 mark.

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Last updated: 2026-11-12

Subject: Life Sciences. Source: Based on Nov 2024 · Paper 1 · Q3.4.1(c). Marks: 1. Not yet checked by a teacher.

## Question 3.4.1(c) (1 mark)

The diagram below shows how the level of thyroxin in the blood is kept steady. Gland Y in the neck makes thyroxin, and the pituitary gland sends a hormone (TSH) to gland Y. Name the disorder in which gland Y becomes enlarged because of a lack of iodine in the diet.

Figure: Flow diagram with two boxes: GLAND Y on the left and PITUITARY GLAND on the right. A dashed upper loop carries ‘Level of thyroxin (X)’ from gland Y to the pituitary, and returns to gland Y marked ‘Less TSH’. A solid lower loop carries ‘Level of thyroxin (Z)’ from gland Y to the pituitary, and returns marked ‘More TSH’.

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[Answer this question](https://sharpkop.co.za/life-sciences/2024-nov-p1/q3-4-1-c/) and see it marked mark by mark, with the reason for every lost mark.

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