In humans, the number of autosomal chromosomes in a sperm is: MCQ with Answer and Explanation

Explanation:
Amphibia (e.g., frogs, toads, salamanders) are characterized by their dual habitat (amphi = both, bios = life). They can live in water and on land. They have moist, glandular skin without scales, which aids in respiration. They typically have a larval stage (tadpole) that undergoes metamorphosis to become an adult.

Explanation:
Melatonin is a hormone secreted by the pineal gland, a small endocrine gland located in the brain. Its secretion is highly sensitive to light and dark cycles, being produced in higher amounts at night. Melatonin is crucial for regulating the circadian rhythm (sleep-wake cycle), maintaining biological clocks, and influencing seasonal reproductive functions in some animals. Thymosin is from the thymus, oxytocin from the posterior pituitary.

Explanation:
Poultry farming involves rearing birds like chickens for the production of eggs (layers) and meat (broilers). Apiculture (beekeeping) not only produces honey but also significantly increases crop yields through enhanced pollination by bees. Dairy farming focuses on the breeding and rearing of cattle, buffaloes, etc., for milk production, not fish (which is pisciculture). Thus, statements 1 and 2 are correct.