Question

cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. which of the following terms best describes this expression of phenotypes?

○ incomplete dominance
○ multiple alleles
○ pleiotropy
○ epistasis

Explanation:

• Incomplete dominance is when the heterozygous phenotype is intermediate between the two homozygous phenotypes.
• Multiple alleles refer to a gene having more than two alleles in a population.
• Pleiotropy occurs when a single gene affects multiple phenotypic traits. Cystic fibrosis affects multiple organs (lungs, pancreas, digestive system) which is a case of one gene (the CFTR gene) having multiple phenotypic effects.
• Epistasis is when one gene masks or modifies the expression of another gene.

Answer:

pleiotropy