Waec Model Questions Vol1 2017 Biology Question 8

Practice objective / multiple choice question 8 from the 2017 Waec Model Questions Vol1 Biology examination.

Waec Model Questions Vol1 2017 Biology Objective / Multiple Choice Hard Difficulty
Question 8 WAEC_MODEL_QUESTIONS_VOL1 • 2017 • BIOLOGY • objective

A 7‑year‑old child presents with growth retardation, swollen ankles, and a diet low in green leafy vegetables. Laboratory results show serum calcium 8.0 mg/dL (normal 9-11), serum phosphate 2.5 mg/dL (normal 3-4.5), and alkaline phosphatase 350 IU/L (normal 30-120). Identify the vitamin deficiency, describe the hormonal regulation that is disturbed, and predict the effect on bone mineralisation.

Answer Options

Correct Answer A. Vitamin D deficiency; reduced calcitriol leads to low calcium absorption and secondary hyperparathyroidism, causing defective bone mineralisation (rickets).
B. Vitamin D deficiency; increased calcitriol leads to high calcium absorption and primary hypoparathyroidism, causing excessive bone mineralisation (osteopetrosis).
C. Vitamin C deficiency; impaired collagen synthesis leads to low calcium absorption and secondary hyperparathyroidism, causing defective bone mineralisation (rickets).
D. Vitamin K deficiency; reduced calcitriol leads to low calcium absorption and secondary hyperparathyroidism, causing defective bone mineralisation (rickets).
Correct Answer
A
Correct Option:
Vitamin D deficiency; reduced calcitriol leads to low calcium absorption and secondary hyperparathyroidism, causing defective bone mineralisation (rickets).

About This Question

This is Waec Model Questions Vol1 2017 Biology Question 8. It is a objective / multiple choice question from the 2017 Waec Model Questions Vol1 Biology examination.

Difficulty level: Hard .

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