Question

Select ALL the correct answers.
Which of the following statements about genes and traits is true?

A single trait can be controlled by multiple genes.
A single gene can influence multiple traits.
A single gene can control a single trait.
A single trait can alter multiple genes.

Answer 1

Correct answers: 1, 2, and 3.

- A single trait can be controlled by multiple genes — True (polygenic inheritance; e.g., human height, skin color).
- A single gene can influence multiple traits — True (pleiotropy; e.g., mutations in a gene causing cystic fibrosis affect lungs, pancreas, etc.).
- A single gene can control a single trait — True in many simple (Mendelian) cases where one gene largely determines a trait (e.g., some pea traits studied by Mendel).

- A single trait can alter multiple genes — False; traits are the result of gene action, not the cause of changes in multiple genes.