What Principle Is Demonstrated by the Findings That Mechanical Stimulation

question 34

Multiple Choice

What principle is demonstrated by the findings that mechanical stimulation of the genitals elicits sex-related behaviors in animals whose spinal cord has been cut?

• A) Sexual reflexes cannot occur without the brain.
• B) The brain is not required for the sexual reflexes of erection and ejaculation.
• C) Sexual orientation is dependent on spinal mechanisms.
• D) Pathways from the hypothalamus to the spinal cord are key to sexual behavior.
• E) Male sexual behavior can at times appear to be brainless.

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Definitions:

Deuterostomes

A category of animals characterized by their embryo development; the first opening (the blastopore) becomes the anus.

Bilaterally Symmetrical

Bilaterally Symmetrical refers to organisms that can be divided into matching halves along a single plane, indicative of a high level of organizational complexity.

Hox Genes

A group of related genes that control the body plan of an embryo along the head-tail axis, determining the type and position of body segments.

Bilaterally Symmetric

A form of symmetry where an organism can be divided into two equal halves on a single plane, showing mirror-image right and left sides.