NEET BIOLOGY

Detailed explanation-1: -Animals that cannot generate internal heat are known as poikilotherms (poy-KIL-ah-therms), or cold-blooded animals. Insects, worms, fish, amphibians, and reptiles fall into this category-all creatures except mammals and birds.

Detailed explanation-2: -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-3: -Warm-blooded animals, such as mammals and birds, were able to maintain their body temperature regardless of the surroundings. Cold-blooded animals, such as reptiles, amphibians, insects, arachnids and fish, were not.

Detailed explanation-4: -Cold-blooded animals do not maintain a constant body temperature. They get their heat from the outside environment, so their body temperature fluctuates, based on external temperatures.