Cystic Fibrosis Is a Recessive Disorder

question 21

Multiple Choice

Cystic fibrosis is a recessive disorder. If a couple, each of whom is heterozygous for the CFTR mutation, have children, what is the probability that they will have a child with cystic fibrosis?

• A) 0 percent
• B) 25 percent
• C) 50 percent
• D) 75 percent
• E) 100 percent

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Definitions:

Ectoderm

The outermost layer of cells or tissue of an embryo in early development, giving rise to the formation of the nervous system and skin.

Epithelial Tissue

A type of tissue that lines the cavities and surfaces of blood vessels and organs throughout the body, providing protection, absorption, and secretion.

Connective Tissue

Connective tissue supports, binds together, and protects tissues and organs of the body with various types including loose, dense, cartilage, bone, and blood.

Muscle Tissue

Specialized tissue composed of cells or fibers that contract to produce movement or maintain the posture of the body.