Recent Studies with Identical Twins Have Supported the View That

question 50

Multiple Choice

Recent studies with identical twins have supported the view that _________of the variance in liability to develop alcoholism can be traced to genetic factors.

• A)all
• B)approximately 10%
• C)approximately 50%
• D)approximately 90%

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Definitions:

Melanin

A pigment that gives human skin, hair, and eyes their color and offers protection against UV radiation.

Keratin

A type of structural protein that is a key component of the skin, hair, nails, and the outer layer of cells.

Protein

Large biological molecules, or macromolecules, consisting of one or more long chains of amino acid residues, functioning in various roles within organisms.

Melanin Production

The process by which cells known as melanocytes produce melanin, a pigment that colors the skin, hair, and eyes.