Some Animals Have No Gills When Young, but Then Develop

question 63

Multiple Choice

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 (basal metabolic rate) 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 BMR.
• D) Relative to their surface area, the young have more body volume in which they can store oxygen for long periods of time.

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Definitions:

CNS

The central nervous system, consisting of the brain and spinal cord, responsible for processing and transmitting information throughout the body.

Calm

A state of peace and tranquility, with an absence of stress, agitation, or excitement.

Muscles

Tissues in the body capable of contraction, making movement possible and playing a critical role in bodily function and maintained posture.

Peripheral Nervous System

The part of the nervous system outside the brain and spinal cord, including sensory and motor neurons.