[Campbell Biology P.329] What is pleiotropy? | Practice Question

What is pleiotropy?

  • A: When a single gene affects only one phenotypic character.
  • B: When a single gene has multiple phenotypic effects.
  • C: When two or more genes affect a single phenotypic character.
  • D: When the environment influences the expression of a gene.

Explanation

The text defines pleiotropy as 'when a single gene produces multiple phenotypic effects'. It gives examples like the gene for flower color also affecting seed coat color in peas, and the multiple symptoms of cystic fibrosis and sickle-cell disease.