In humans, calcium plays a role in
(A) Bone formation
(B) Blood clotting
(C) Muscle function
(D) Blood formation
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (B) and (C) only
Calcium is the most plentiful mineral in the human body; most of it is stored in the bones and teeth, and the small amount in the blood and cells controls clotting and muscle contraction.
(A) Bone formation Correct. Bones and teeth are hardened by calcium phosphate, so calcium (with vitamin D to absorb it) is needed for strong bones.
(B) Blood clotting Correct. Calcium ions are a clotting factor: several steps of clotting need calcium, including the change of prothrombin into thrombin.
(C) Muscle function Correct. A muscle contracts when calcium ions are released inside the muscle fibre and let the actin and myosin filaments slide over each other.
(D) Blood formation Incorrect. The making of blood cells and haemoglobin depends on iron, vitamin B12 and folic acid, not on calcium.