Which of the following genotypes would result in a true-breeding stock?
A)AA or Aa or aa
B)Aa, but not AA or aa
C)AA, but not Aa or aa
D)aa, but not Aa or AA
E)AA or aa, but not Aa

Question

Quizplus · Accepted Answer

True-breeding stock refers to a group of organisms that, through multiple generations of breeding, consistently display a particular trait. This can only occur if the genotype remains constant through multiple generations. The only genotype that guarantees this is homozygous (AA or aa), as heterozygous (Aa) genotypes can produce different gametes and offspring, leading to variation in the trait. Therefore, either AA or aa (homozygous) but not Aa (heterozygous) would result in a true-breeding stock. Choice E accounts for this by including both homozygous genotypes but excluding the heterozygous genotype.

Which of the Following Genotypes Would Result in a True-Breeding