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 one of the objective questions from the 2017 Waec Model Questions Vol1 Biology examination.

Difficulty level: Hard .

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