What is the difference between a dominant trait and a recessive trait?

Question

Responses

A dominant trait is expressed if at least one allele is present
A dominant trait is expressed if at least one allele is present - no response given

A dominant trait is only expressed if two alleles are present.
A dominant trait is only expressed if two alleles are present. - no response given

A recessive trait is only expressed if one allele is present.
A recessive trait is only expressed if one allele is present. - no response given

There is no difference between them.

Answer 1

The correct response that defines the difference between a dominant trait and a recessive trait is:

• A dominant trait is expressed if at least one allele is present.

In contrast, a recessive trait is only expressed if two copies of the recessive allele are present (one from each parent). Therefore, a recessive trait will not be expressed if there is at least one dominant allele present.