The trait that will always be expressed if one copy of an allele is present.

The trait that will be expressed only if two copies of the allele are present.

Being able to roll the tongue is a dominant trait (T). Not being able to roll the tongue is a recessive trait (t). A persons genes are tt. Which trait would they have?

Black hair (H) is a dominant gene in guinea pigs and black yellow (h) is recessive. What color hair would a guinea pig have if it got a recessive gene (h) from mom and a dominant gene (H) from dad?

Black hair (H) is a dominant gene in guinea pigs and black yellow (h) is recessive. What color hair would a guinea pig have if it got a recessive gene (h) from mom and a recessive gene (h) from dad?