For the Following Questions, Refer to the Graph of an Action

question 23

Multiple Choice

For the following questions, refer to the graph of an action potential.

-Action potentials are normally carried in only one direction: from the axon hillock toward the axon terminals. If you experimentally depolarize the middle of the axon to threshold, using an electronic probe, then

• A) no action potential will be initiated.
• B) an action potential will be initiated and proceed only in the normal direction toward the axon terminal.
• C) an action potential will be initiated and proceed only back toward the axon hillock.
• D) two action potentials will be initiated, one going toward the axon terminal and one going back toward the hillock.
• E) an action potential will be initiated, but it will die out before it reaches the axon terminal.

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Definitions:

Germ Layer

Primary tissue layer of a vertebrate embryo—namely, ectoderm, mesoderm, or endoderm.

Ectoderm

Outermost primary tissue layer of an animal embryo; gives rise to the nervous system and the outer layer of the integument.

Differentiate

To recognize or ascertain what makes something or someone different, or in biology, the process by which cells or tissues change from relatively generalized to specialized kinds, during development.

Derived

Obtained from a specific source or originating from something; made by altering or modifying something else.