Question

John has two sisters and two brothers. Three of the five children in the family have dark brown hair, one has red hair, and one has light brown hair. The variation in hair color is due to the input of multiple genes. What pattern of inheritance is exhibited here?
A) Polygenetic inheritance
B) Co-dominance
C)Pleiotropy

Answer 1

Pleiotropy is not the answer because it involves one gene influencing multiple phenotypical traits. Co-dominance is also not right because it involves genes of only one locus, and it says in the question that "The variation in hair colour is due to multiple genes"

The answer is A) polygenetic inheritance because multiple genes influence one phenotypical trait (hair colour).

Answer 2

@niels5x9 thank you!

Answer 3

You're welcome