The disease 'anemia' is most commonly caused by deficiency of: MCQ with Answer and Explanation

Explanation:
The skin and mucous membranes form the first line of defense (innate immunity), acting as physical barriers that prevent pathogens from entering the body. White blood cells (leukocytes), including phagocytes and lymphocytes, are the cellular components of the immune system that identify, attack, and destroy pathogens. Antibiotics are drugs specifically designed to kill or inhibit the growth of bacteria by targeting their unique structures or metabolic pathways; they are completely ineffective against viruses. Thus, statements 1 and 2 are correct.

Explanation:
Cellular respiration breaks down glucose and other nutrients in the presence of oxygen to produce ATP. Photosynthesis builds glucose, fermentation is anaerobic energy production, transpiration is water loss.

Explanation:
Selective permeability means the membrane controls entry and exit of substances based on size, charge, and solubility. R defines this property and explains A.