Q.Write eight salient features of the class Amphibia.

Amphibians are cold-blooded vertebrates adapted to both water and land, marked by moist glandular skin, a three-chambered heart, and indirect development through a tadpole larva.

Eight salient features of class Amphibia:

1. Ectothermic (cold-blooded): body temperature varies with the surrounding environment; there is no internal thermoregulation.
2. Dual habitat: amphibians characteristically live part of their life in water and part on land ("amphi" = both, "bios" = life) — hence the class name.
3. Skin: moist, glandular, and generally without scales; richly supplied with blood vessels, allowing cutaneous (skin) respiration in addition to lungs.
4. Respiration: by gills in the aquatic larval stage, and by lungs and skin in the terrestrial adult stage; some (e.g., certain salamanders) are lungless and respire entirely through skin/buccal cavity.
5. Heart: three-chambered, with two atria and one ventricle, allowing some mixing of oxygenated and deoxygenated blood.
6. Limbs: typically two pairs of pentadactyl (five-fingered) limbs adapted for jumping/walking (though limbless in caecilians). …