Question

What physiological mechanism of exchange is used by ectotherms and endotherms in respiration and thermoregulation?

a. balancing exchange

b. counter current exchange

c. bidirectional exchange

d. homeophasic exchange

e. cross current exchange

Answer 1

ANS: BALANCING EXCHANGE

Heat is exchanged by animals with their environment through radiation, conduction, evaporation and sometimes by convection. Body temperature depends on the balance between heat generated by the organism and heat exchanged with lost to or gained from the environment for both endotherms and ectotherms. There are mainly three ways by which an organism can exchange heat with its environment: radiation, conduction and evaporation. Some adaptations increase heat production in endotherms when it’s cold while some in both endotherms and ectotherms, increase or decrease exchange of heat.

Main three broad categories of thermoregulatory mechanisms are:

• Changing behavior
• Increasing metabolic heat production
• Controlling the exchange of heat with the environment