The Fact That Identical Twins Have Approximately a 50 Percent

question 262

Multiple Choice

The fact that identical twins have approximately a 50 percent concordance rate for homosexuality was presented as evidence for the possible basis for sexual orientation.

• A) biological
• B) psychoanalytical
• C) cultural
• D) environmental

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Definitions:

Sphincter

A circular muscle that controls the passage of substances through an opening in the body, such as the anus or the esophagus.

Orbicular

Shaped like a circle or orbit; referring to muscles that encircle openings in the body, such as the orbicularis oris muscle around the mouth.

Antagonist

Muscle that works in opposition to another muscle.

Opposition

Movement of the thumb and little finger toward each other; movement of the thumb toward any of the fingers.