Question

true breeding parents ______ trait variant(s) to their offspring. (1 point)
○ will pass two
○ might only pass one
○ will not pass
○ can only pass one

Explanation:

True - breeding organisms are homozygous for a particular trait (e.g., if the trait is flower color and the true - breeding parent has the genotype for purple flowers as PP). When they reproduce, during the formation of gametes, according to Mendel's law of segregation, each gamete will receive one allele for the trait. But since the parent is homozygous (has two identical alleles for the trait), all the gametes produced will carry the same allele for that trait. So, when true - breeding parents produce offspring (usually through self - pollination or crossing with another true - breeding parent of the same trait variant), they can only pass one type of trait variant (allele) for that particular trait. Let's analyze each option:

• "will pass two": True - breeding parents are homozygous, and during gamete formation, they pass one allele per gamete. Offspring receive one allele from each parent, but the parent itself can only contribute one type of allele for the trait (since it's homozygous), so this is wrong.
• "might only pass one": True - breeding parents, being homozygous, will always pass one type of allele for the trait (not just "might"). So this is incorrect.
• "will not pass": This is clearly wrong as true - breeding parents do pass their trait variants to offspring (that's why they are true - breeding, the offspring show the same trait).
• "can only pass one": Since true - breeding parents are homozygous (e.g., AA or aa), they have two identical alleles for a trait. When producing gametes, each gamete gets one allele, and all gametes will have the same allele (either A or a in the example). So when they pass on the trait variant (allele) to offspring, they can only pass one type of trait variant for that trait.

Answer:

D. can only pass one