(a) Hibernation and Aestivation:-
Hibernation:-
1. Hibernation is a state of reduced activity in some organisms to escape cold winter conditions.
2. Bears and squirrels inhabiting cold regions are examples of animals that hibernate during winters.
Aestivation:-
1. Aestivation is a state of reduced activity in some organisms to escape desiccation due to heat in summers.
2. Fishes and snails are examples of organisms aestivating during summers.

(b) Ectotherms and Endotherms:-
Ectotherms:-
1. Ectotherms are cold blooded animals. Their temperature varies with their surroundings.
2. Fishes, amphibians, and reptiles are ectothermal animals.
Endotherms:-
1. Endotherms are warm blooded animals. They maintain a constant body temperature.
2. Birds and mammals are endothermal animals.

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