A Normal, Healthy Animal Never Contracts the Flexor Muscles and the Extensor

question 64

Multiple Choice

 A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not?

• A) When the interneuron sends excitatory messages to one, inhibitory messages go to the other.
• B) Both muscles are mechanically connected in a way that makes it impossible for both to contract at the same time.
• C) Such coordination is learned through prenatal movement.
• D) Both muscles are controlled by branches of the same axon.

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Definitions:

Chromosomes

Structures within cells that contain DNA and carry genetic information for the development and functioning of living organisms.

Genes

The basic physical and functional units of heredity, made up of DNA, that influence traits and characteristics.

Behavioral Genetics

An interdisciplinary field of study concerned with genetic contributions to individual differences in behavior and personality.

Genetic Bases

The underlying genetic makeup that contributes to the physical and behavioral characteristics of an organism.