NEET BIOLOGY

Detailed explanation-1: -ectotherm, any so-called cold-blooded animal-that is, any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface. The ectotherms include the fishes, amphibians, reptiles, and invertebrates.

Detailed explanation-2: -For any ectotherm, even brief exposure to subzero temperatures carries the risk of irreparable injury or death. Cold impairs cellular functions by rigidifying membranes, slowing ion pumps, inducing oxidative damage, denaturing proteins, and altering energy balance.

Detailed explanation-3: -For ectotherms, on the other hand, body temperature mainly depends on external heat sources. That is, ectotherm body temperature rises and falls along with the temperature of the surrounding environment.

Detailed explanation-4: -Cold-blooded animals cannot generate their own body heat, but they do regulate it by changing their environment. Alligators and other reptiles often lie in the sun to warm themselves. On the other hand, they cool off by taking a dip in the water, moving into the sade of a rock or crawling into a burrow in the ground.

Detailed explanation-5: -Ectotherms simply rely on the temperature of their environment (read, environment, not just the air) to reach their thermal optimum, whether it be high in the case of the monitor lizards or low in the case of the salamanders. And of course, they can get too hot and too cold just like we can.