Which of the following animals belongs to the phylum Annelida? MCQ with Answer and Explanation

Explanation:
The skin and mucous membranes act as primary physical barriers in innate immunity, preventing pathogen entry. Phagocytosis by macrophages and neutrophils is a non-specific (innate) cellular defense mechanism, not a specific immune response. Memory B and T cells are produced during the primary specific immune response and provide rapid, long-lasting immunity upon re-exposure. Thus, statements 1 and 3 are correct.

Explanation:
Bombyx mori is the domesticated silkworm, whose caterpillar spins a silk cocoon. The silk thread is obtained by boiling cocoons. Apis mellifera is the honeybee, Labeo rohita is a fish (rohu), Drosophila is fruit fly used in genetics. Sericulture involves mulberry cultivation, silkworm rearing, and reeling of silk. India is the second largest silk producer.

Explanation:
Ammonia (NH₃) is highly toxic and requires large volumes of water for its excretion; hence it is produced by aquatic animals. Urea is less toxic, uric acid least toxic and water-insoluble. Creatinine is a minor waste. Ammonia is converted to urea in the liver via the urea cycle in ureotelic organisms.