Many snakes and lizards live in the desert, where temperatures are high during the day and cold at night. How does the temperature range affect the size of the snakes and lizards?

A. High daytime temperatures allow them to grow as large as the food supply will allow.

B. Cold nighttime temperatures limit their size, because large ectotherms need a long time to warm up in the sun.

C. High daytime temperatures limit their size, because large endotherms would overheat on very hot days.

D. Cold nighttime temperatures limit their size, because large endotherms would lose too much of their body heat.

Snakes and lizards are cold-blooded animals. This type of animal cannot maintain a constant body temperature and depends on the temperature of the environment to keep warm and keep its organs and metabolism working.

Room temperature is so important to these animals that they even determine the size of their bodies. For these animals, high temperatures allow them to have their metabolism accelerated, so they can grow as much as the availability of food allows. On the other hand, if there is not enough food, or very cold temperatures, they will need to be smaller in size, as the metabolism will be slow.