Some animals have no gills when young,but then develop gills that grow larger as the animal grows larger.What is the reason for this increase in gill size?
A)The young of these animals are much more active than the adult,which leads to a higher BMR and therefore a higher need for oxygen.
B)Relative to their volume,the young have more surface area across which they can transport all the oxygen they need.
C)The young have a higher basal metabolic rate.
D)Relative to their surface area,the young have more volume in which they can store oxygen for long periods of time.

Question

Quizplus · Accepted Answer

As young animals grow larger, their overall volume increases faster than their surface area. This means that there is a decrease in the surface area-to-volume ratio, which makes it harder for oxygen to be transported across the body via diffusion. Therefore, the increase in gill size allows for a larger surface area through which oxygen can be transported, ensuring that enough oxygen is brought to the growing body's tissues.

Some Animals Have No Gills When Young,but Then Develop Gills