The vast majority of animals and nearly all plants cannot maintain a constant internal environment. What is this called?

Nektons are

Which of the following pairs is mismatched?

Which one of the following is the correct matching of a plant, its habit, and the forest type where it normally occurs?

In summer,when the outside temperature is higher than our body temperature,we sweat profusely. The resulting evaporative cooling,similar to what happens with a desert cooler in operation,brings down the body temperature. In winter,when the temperature is much lower than $37^{\circ}C$,we start to shiver,a kind of exercise which produces heat and raises the body temperature. These organisms are called:

Which feature of an elephant suggests that it is an animal of a hot climate?