In a two-point test-cross analysis, a dihybrid F₁ fly is crossed to a __________. A)pure-breeding mate with a dominant phenotype (AABB) B)pure-breeding mate with a recessive phenotype (aabb) C)heterozygote mate (AaBb) D)mate that is dominant for one gene and recessive for the other (AAbb or aaBB) E)second dihybrid F₁ fly (sibling cross)

Question

Quizplus · Accepted Answer

A two-point test-cross is used to determine the linkage between two genes. To do this, we need to cross an individual with a dominant phenotype (F₁) with an individual that is homozygous recessive for both genes. This allows us to observe the phenotypes of the offspring and determine if the genes are linked or unlinked. Therefore, the best choice is a pure-breeding mate with a recessive phenotype (aabb).

In a Two-Point Test-Cross Analysis, a Dihybrid F1 Fly Is

In a Two-Point Test-Cross Analysis, a Dihybrid F₁ Fly Is