The specific part of the respiratory system where gas exchange occurs is the: MCQ with Answer and Explanation

Explanation:
Insulin, secreted by the pancreas, promotes cellular glucose uptake, lowering blood sugar levels. Adrenaline (epinephrine) from the adrenal medulla triggers the fight-or-flight response, increasing heart rate and energy supply. Thyroxine, produced by the thyroid gland, requires iodine as an essential component for its synthesis; iodine deficiency causes goiter. All statements are correct.

Explanation:
DNA replication is semiconservative and uses DNA polymerase. In eukaryotes, it occurs in the nucleus, not cytoplasm. So statement 3 is incorrect.

Explanation:
The retina is the inner lining of the eye containing rods and cones, the photoreceptor cells for vision. The cochlea is a spiral-shaped cavity in the inner ear containing the organ of Corti, essential for converting sound vibrations into nerve impulses. Taste buds are primarily on the tongue but are also found on the soft palate, epiglottis, and upper esophagus. Thus, statements 1 and 2 are correct.