A Neurophysiologist Is Investigating Reflexes in Two Different Animals: a Crab

question 7

Multiple Choice

A neurophysiologist is investigating reflexes in two different animals: a crab and a fish. Action potentials are found to pass more rapidly along the fish's neurons. What is a likely explanation?

• A) The fish's axons are smaller in diameter than the axons in the crab.
• B) The fish's axons are myelinated. The crab's axons are not myelinated.
• C) The fish's axons are not myelinated. The crab's axons are myelinated.
• D) There is a higher percentage of ion channels in the axons of the crab compared with the percentage of ion channels in fish axons.

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Definitions:

Color Discrimination

The ability to distinguish between different wavelengths of light, perceived by humans as colors.

Farsightedness

An eye condition where distant objects are seen more clearly than near objects due to the light rays being focused behind the retina.

Night Vision

The ability to see in low-light conditions, often enhanced by certain technological devices or natural biological adaptations.

Hypodermis

Innermost layer of skin composed of fat.