Two Genes Control Fur Color in Labrador Retrievers

question 52

Multiple Choice

Two genes control fur color in Labrador retrievers.The first gene determines whether the pigment to be deposited in the hair will be black or brown.The second gene determines whether the pigments are put into the dog's hair at all.A dog homozygous for the recessive allele of this second gene will be yellow because no pigment is deposited in its fur.This is an example of

• A) epistasis.
• B) pleiotrophy.
• C) codominance.
• D) incomplete dominance.

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Definitions:

Hypothalamus

A region of the brain below the thalamus, coordinating both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems.

Endocrine Glands

Glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct.

Major Hormones

Hormones that have significant roles in the regulation of various physiological processes, including growth, metabolism, and reproductive function.

Insulin

An agent created by the pancreas that oversees the maintenance of blood glucose levels, helping tissues to take in glucose.