Check Your Understanding 5.042 An inventor claims to have developed an engine that does not use fuel but operates as a power cycle at steady state while receiving energy by heat transfer from the surrounding atmosphere and discharging energy by heat transfer to the surrounding atmosphere. This would be an excellent project to invest in.

1.True
2.False

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'