Question

alleles interact with each other in various ways to produce observable traits in an organism. in some cases, one allele overpowers another, while in other cases, both alleles are partially or completely expressed.
for example, if an individual inherits the allele for blood type a on chromosome 9 from their mother, and the allele for blood type b on chromosome 9 from their father, they will have type ab blood.
which statement best describes how an individuals alleles affect their traits?
the allele inherited from the father always overpowers the other allele.
the allele inherited from the mother always overpowers the other allele.
one of the two alleles for a gene is chosen at random to affect an individuals traits.
alleles interact to affect an individuals traits

Explanation:

The first two options are incorrect as alleles don't always follow a pattern of one (from father or mother) always overpowering. The third option is wrong because alleles don't act randomly. The text clearly states that alleles interact (e.g., in blood - type AB, both A and B alleles are expressed).

Answer:

Alleles interact to affect an individual's traits.