Which of the following statements about evolution is correct? MCQ with Answer and Explanation

Explanation:
Bacillus thuringiensis (Bt) is a bacterium producing crystal (Cry) proteins toxic to specific insect larvae, used as a biological insecticide. DDT, malathion, and lindane are synthetic chemical pesticides. Biopesticides are eco-friendly, target-specific, and biodegradable. Bt formulations are used in organic farming. The cry gene is also used in GM crops like Bt cotton.

Explanation:
Robert Hooke, in 1665, observed thin slices of cork under a compound microscope and saw box-like structures he named 'cells'. Leeuwenhoek observed live cells, Brown discovered the nucleus, Virchow proposed cells arise from cells.

Explanation:
ADH (vasopressin), released from the posterior pituitary, increases water permeability of the collecting duct and distal tubule, promoting water reabsorption and producing concentrated urine. Its secretion is stimulated by increased plasma osmolarity or decreased blood volume. Aldosterone regulates sodium reabsorption. Parathyroid hormone and calcitonin regulate calcium.