Answer: Iodine deficiency leading to low thyroid hormone production and compensatory TSH-driven thyroid enlargement.
- A A long-term deficiency of circulating insulin hormone normally secreted by the pancreas itself in routine practice
- B Iodine deficiency leading to low thyroid hormone production and compensatory TSH-driven thyroid enlargement
- C Excess secretion of cortisol hormone from the adrenal cortex under prolonged chronic stress overall in most cases
- D Excess secretion of growth hormone released from the anterior pituitary gland over time under typical conditions
Correct answer: B. Iodine deficiency leading to low thyroid hormone production and compensatory TSH-driven thyroid enlargement
Explanation: Goitre is enlargement of the thyroid gland. Most common cause: iodine deficiency (needed for thyroid hormone T<sub>3</sub>/T<sub>4</sub> synthesis). Low T<sub>3</sub>/T<sub>4</sub> → high TSH (from pituitary) → TSH stimulates thyroid growth → goitre. Endemic in inland areas with iodine-poor soil/water.
The Plasmodium parasite needs both hosts: the female Anopheles mosquito injects sporozoites while biting (infecting the human liver and RBCs, causing the malaria fever cycle), then picks up gametocytes from an infected person's blood, completing the parasite's sexual stage inside the mosquito.
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.