Which of the following organisms would be likely to use the least energy per kilogram of body weight to maintain its temperature in a preferred range?

Question

a. a whale in the Arctic Ocean
b. a clam remaining submerged at low tide
c. a tuna swimming in the deep ocean
d. a lizard in a desert environment
e. a human in a tropical environment

Answer 1

B; Clams are poikilotherms with little need to warm their bodies for movement. As long as they remain covered by water, they will tolerate any temperature changes they are likely to experience. Whales have effective means of heat conservation, but they still must use energy to maintain body temperature in cold water. Tunas use swimming muscles to generate heat and warm the body core. Lizards use behavioral mechanisms (gaping and bobbing) to generate heat on cold mornings. Humans need to expend some energy to maintain body temperature even in tropical environments, and if they are overheated, use energy in the response that unloads the heat.