The condition in which the blood does not clot properly due to deficiency of clotting factor VIII is: MCQ with Answer and Explanation

Explanation:
Vitamin A (retinol) is essential for the synthesis of rhodopsin, the visual pigment in rod cells responsible for low-light vision. Deficiency leads to night blindness (nyctalopia) and, if severe, xerophthalmia and permanent blindness. Vitamin B₁ deficiency causes beriberi, C scurvy, D rickets.

Explanation:
Salivary amylase (ptyalin) initiates starch digestion in the mouth, hydrolyzing it into maltose and dextrins. Pepsin digests protein, lipase fats, rennin curdles milk. Amylase works optimally at neutral pH.

Explanation:
Pleiotropy is a phenomenon where a single gene influences multiple, seemingly unrelated phenotypic traits. Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by a mutation in a single gene (PAH) that codes for the enzyme phenylalanine hydroxylase. This single mutation leads to multiple effects: intellectual disability, reduced hair and skin pigmentation, and musty odor.