Blood platelets assist in arresting bleeding by

Correct Answer: B

Rationale: Platelets aggregate at injury sites, adhering to collagen to form plugs, and release clotting factors and vasoconstrictors like serotonin.

Correct Answer: A

Rationale: Thirst is triggered by increased plasma tonicity (osmoreceptors in hypothalamus); low volume also stimulates it, and ADH increases.

Correct Answer: A

Rationale: Respiratory acidosis is defined by high PCO2; kidneys compensate by raising HCO3-.

Correct Answer: C

Rationale: Factor VIII deficiency (hemophilia A, X-linked) prolongs clotting time; mild reductions cause bleeding.

Correct Answer: C

Rationale: Meristematic tissues are group of living cells which are present in the plant body and divide to form new cells.