Vertebrates and Cephalopods Have Eyes That Are Structurally Very Similar

question 12

Multiple Choice

Vertebrates and cephalopods have eyes that are structurally very similar. One key difference is that cephalopods do not have a blind spot. What causes the blind spot in vertebrates?

• A) The eye has 2 lens, so there is an area where the lenses converge where focus is lost and the picture vanishes.
• B) An area of the retina does not have photoreceptors on it.
• C) Axons of the ganglion cells exiting the eye through the optic nerve block some of the photoreceptor cells on the inner surface of the retina.
• D) Both A and B are reasons why vertebrates have a blind spot.
• E) Both B and C are reasons why vertebrates have a blind spot.

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Definitions:

Glutamate

A major excitatory neurotransmitter in the brain, involved in memory and learning.

Neurotransmitter

Chemical substances in the nervous system that transmit signals from one neuron to another.

Inhibitory

Pertaining to a neurotransmitter, hormone, or other substance that decreases the likelihood of a neuron firing an action potential.

Excitatory

Referring to substances or processes that increase the likelihood of a neuron firing and transmitting an electrical signal.