Deficiency of vitamin A primarily affects: MCQ with Answer and Explanation

Explanation:
Natural passive immunity occurs when pre-formed antibodies are transferred naturally from one individual to another. During pregnancy, maternal antibodies (primarily IgG) cross the placenta to the fetus, providing temporary protection against diseases the mother is immune to. Colostrum (mother's milk) also provides IgA antibodies to the newborn.

Explanation:
Max Theiler developed the attenuated yellow fever vaccine (17D strain) in the 1930s, winning the Nobel Prize. Pasteur rabies, Jenner smallpox, Salk polio.

Explanation:
Carbohydrates are the body's primary and most efficient source of energy, broken down into glucose to fuel cellular activities. Proteins are essential macronutrients composed of amino acids, crucial for the growth, maintenance, and repair of body tissues, as well as forming enzymes and hormones. Fats are essential for numerous bodily functions, including providing concentrated energy, forming cell membranes, insulating the body, and absorbing fat-soluble vitamins. Thus, statements 1 and 2 are correct.