Which principle to explain the reason behind why alleles for a single trait separate from each other when gametes are made to ensure that each gamete only carries one allele?
a. segregation
b. incomplete dominance
c. dominance
d. independent assortment

Segregation

For a trait to show or express itself in an individual it must have two types of the same allele (for example P and p) showing on the chromosomes. The showing of both alleles on an offspring's chromosomes means that both parents have the same trait and that is why there is a chance for an allele to become dominant in other words to express itself in the offspring. However if only one allele is transferred in the genes of the offspring that means that the trait that the allele is responsible for, will remain unexpressed.