Assertion (A): Xerophytes have a thick cuticle. Reason (R): Thick cuticle reduces water loss in dry environments. MCQ with Answer and Explanation

Explanation:
Codominance occurs when both alleles in a heterozygote are fully and equally expressed. In the ABO blood group system, the IA and IB alleles are codominant. An individual with the genotype IAIB will have both A and B antigens on the surface of their red blood cells, resulting in the AB blood type. It also involves multiple alleles (IA, IB, i).

Explanation:
Vitamin C (ascorbic acid) is a cofactor for prolyl and lysyl hydroxylase enzymes that hydroxylate proline and lysine in collagen synthesis, necessary for stabilizing collagen triple helix. Deficiency leads to impaired collagen formation, causing scurvy—fragile blood vessels, bleeding gums, poor wound healing. Vitamin A is for vision, D for bone, K for clotting.

Explanation:
Prokaryotes lack a true nucleus and nuclear membrane; their genetic material is concentrated in a nucleoid region. They possess ribosomes (70S), a plasma membrane, and usually a cell wall. The absence of membrane-bound organelles is a defining feature distinguishing them from eukaryotes. Thus, the nuclear membrane is absent.