(Question 1 continued)
(d)
Birds and mammals maintain constant body temperature despite considerable losses
of body heat to the environment. In insects such as mealworms, body temperature is
variable and is often the same as the temperature of the environment or only slightly
above it. Analyse the data in the bar charts, using this information.
[2]
(e) Using all the relevant data in this question, discuss the use of insects as a major food
source for humans.
[3]
Answers
Answer:
Birds and mammals being homeothermic (capable of maintaining constant body temperature) have evolved a mechanism to regulate their metabolic rate. An inverse relationship is observed between metabolic rate and body weight from the plot of the rate of oxygen consumption versus body weight of different mammals. On the other hand, there is the directly proportional relationship between metabolic rate and surface area to volume ratio. From the given figure it is evident that more internal heat per gram of body weight is generated by shrew and more heat is lost to the environment than the horse. Thus maintenance of constant body temperature is more difficult for small animals in cold weather.
What would happen if all the vital organs of an animal are kept at approximately the same temperature?
A
It could not survive in a desert environment
B
It sweats excessively and becomes dehydrated in hot weather
C
Its body temperature is determined by the most temperature-sensitive organ
D
It must always have a large supply of water
E
It will be found only on the tundra