A desert lizard (an ectotherm) and a mouse (an endotherm) are placed inside a chamber at 15° C and their body temperatures [ T ( L ) for the lizard and T ( M ) for the mouse ] and metabolic rates [ M ( L ) for the lizard and M ( M ) for the mouse ] are monitored. Which one of the following is correct?

Question

A desert lizard (an ectotherm) and a mouse (an endotherm) are placed inside a chamber at 15° C and their body temperatures [ T ( L ) for the lizard and T ( M ) for the mouse ] and metabolic rates [ M ( L ) for the lizard and M ( M ) for the mouse ] are monitored. Which one of the following is correct? (A) T(L) and M(L) will fall while T(M) and M(M) will increase (B) T(L) and M(L) will increase while T(M) and M(M) will fall (C) T(L) and M(L) will fall, T(M) will remain same and M(M) will increase (D) T(L) and M(L) will remain same and T(M) and M(M) will decrease

Tardigrade Admin · Accepted Answer

Endotherms (animals that use body heat to maintain a constant internal temperature) increases metabolic heat production to keep their body temperature constant, when its cold outside. For ectotherms, on the other hand, body temperature mainly depends on external heat sources. That is why ectotherm body temperature and metabolic rate rises and falls along with the temperature of the surrounding environment.

Q. A desert lizard (an ectotherm) and a mouse (an endotherm) are placed inside a chamber at 15∘C and their body temperatures [T(L) for the lizard and T(M) for the mouse ] and metabolic rates [M(L) for the lizard and M(M) for the mouse ] are monitored. Which one of the following is correct?

T(L) and M(L) will fall while T(M) and M(M) will increase

T(L) and M(L) will increase while T(M) and M(M) will fall

T(L) and M(L) will fall, T(M) will remain same and M(M) will increase

T(L) and M(L) will remain same and T(M) and M(M) will decrease