Read the following and answer the questions that follow:
Dr. Sharma is examining two patients. Patient A has a swollen neck and complains of sluggish metabolism. Patient B is a child whose growth has been significantly slower than that of other children his age, and doctors find no genetic abnormality.
(a) Identify the likely hormonal deficiency in Patient A. Name the hormone, its gland, and the dietary mineral whose absence can cause this condition. (2 marks)
(b) Identify the likely hormonal deficiency in Patient B. Name the hormone and the gland that secretes it. (1 mark)
(c) What general mechanism does the body use to ensure that hormone levels do not become excessively high or low? (1 mark)
Generated by claude-sonnet-4-6 · 2026-06-26 01:02 · grounding rag
Model Answer
(a) Patient A likely has a deficiency of thyroxin (thyroid hormone). Thyroxin is secreted by the thyroid gland. Deficiency of the dietary mineral iodine prevents the thyroid gland from producing enough thyroxin, causing the gland to swell — a condition called goitre.
(b) Patient B likely has a deficiency of growth hormone, secreted by the pituitary gland. Insufficient growth hormone during childhood leads to stunted growth despite no genetic abnormality.
(c) The body uses a feedback mechanism to regulate hormone levels. When the level of a hormone rises or falls beyond the required amount, a signal is sent to the concerned gland to adjust its secretion accordingly.
Source: Control and Coordination (Chapter 6), What you have learnt
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Explanation
- (a) Goitre (swollen neck) is the classic sign of iodine-deficiency leading to low thyroxin. Examiners expect all three: hormone name, gland, and mineral.
- (b) Stunted growth with no genetic cause points to pituitary growth hormone deficiency. Both hormone and gland must be named for full marks.
- (c) "Feedback mechanism" is the exact NCERT term — use it. A brief description of how it works earns the mark. Don't write "negative feedback" specifically unless asked; "feedback mechanism" is sufficient at this level.