The vitamin that acts as an antioxidant and is important for immune function is: MCQ with Answer and Explanation

Explanation:
Bacteria are prokaryotes that primarily reproduce asexually through binary fission, a process where a single cell divides into two identical daughter cells. Fungi reproduce both sexually and asexually, but asexual reproduction commonly occurs through the formation and dispersal of spores (like conidia or sporangiospores). Viruses are obligate intracellular parasites; they lack the metabolic machinery for independent reproduction and must hijack a host cell's machinery to replicate. Thus, statements 1 and 2 are correct.

Explanation:
Alveoli are tiny, thin-walled air sacs surrounded by a network of pulmonary capillaries. Oxygen diffuses from alveolar air into blood, and CO₂ diffuses from blood into alveolar air. Bronchi and bronchioles are air passages, trachea is the windpipe. The large surface area of alveoli (about 70 m²) facilitates efficient gas exchange.

Explanation:
Vitamin A (retinol) is crucial for the maintenance of the cornea and the synthesis of rhodopsin, a pigment necessary for vision in dim light. Vitamin C (ascorbic acid) is essential for the synthesis of collagen; its deficiency leads to scurvy, characterized by bleeding gums and poor wound healing. Vitamin K, not Vitamin D, is essential for the synthesis of prothrombin and other clotting factors. Vitamin D is essential for calcium absorption and bone health. Thus, statements 1 and 2 are correct.