Which is a poikilothermic animal? (NSCL 2018)

✅Explanation: Poikilothermic animals, also known as cold-blooded animals, cannot regulate their internal body temperature and rely on external sources like the sun to do so. Wall lizards are reptiles, and reptiles are classic examples of poikilotherms.

🔑Key Points:

• Cold-blooded animals:
-Cold-blooded animals are animals that are not capable of regulating their body’s temperature according to the temperature of the surrounding.
-They do not have a constant body temperature.
-Cold-blooded animals include reptiles, amphibians, fishes, insects, and other invertebrates.
-These animals are also called poikilothermic animals.

• Warm-blooded animals:
-Warm-blooded animals are the animals that are capable of maintaining a nearly constant body temperature irrespective of the temperature of the environment.
-Their body temperature remains the same as they move from one surrounding to another.
-The temperature control is mostly obtained by regulating their metabolic rates.
-Warm-blooded animals include birds and mammals.
-These animals are also called homeothermic animals.

• Shark:
-Sharks don’t fit the criteria for mammals in the most important respects.
-They don’t produce milk, they don’t have hair, and most of them are cold-blooded.
-The only characteristic they share with mammals is that some shark species give live birth.
-They belong to the class Chondrichthyes and not Mammalia.

• ​Whale:
-Whale belongs to the class Mammalia.
-The whale is a mammal, not a fish, hence it is warm-blooded.
-It is classified under the Phylum Chordata.
-Whales give birth to live offspring (whereas fish hatch their young from eggs), and feed their young (called calves) on milk produced by the female's own body.