At which level of biological organization does the living state first become evident? MCQ with Answer and Explanation

Explanation:
Edward Jenner is considered the father of immunology for pioneering the concept of vaccination by developing the smallpox vaccine. Alexander Fleming discovered the first antibiotic, penicillin, from the fungus Penicillium notatum in 1928. Louis Pasteur made monumental contributions to microbiology and vaccination, but the structure of DNA was discovered by James Watson and Francis Crick in 1953. Thus, statements 1 and 2 are correct.

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.

Explanation:
Actin (thin) and myosin (thick) filaments slide past each other during contraction, powered by ATP. Collagen is structural, hemoglobin transports oxygen.