Question

A testcross between f1 dihybrid flies produces more offspring with both traits like those of one parent or the other than offspring with recombinant-type traits. what best explains these results?

Answer 1

The observed results in a testcross between F₁ dihybrid flies producing more parental-type offspring than recombinant-type offspring can be explained by Mendel's laws of inheritance.

Step-by-step explanation:

The observed results in a testcross between F₁ dihybrid flies producing more parental-type offspring than recombinant-type offspring can be explained by Mendel's laws of inheritance. According to Mendel, traits are inherited independently and segregated randomly in gamete formation. When two dihybrid parents are crossed, the resulting F₁ generation will all express the dominant traits of one parent. However, in the F₂ generation, the traits will segregate and combine randomly, resulting in a ratio of 9:3:3:1 for the phenotypes. This means that there will be more offspring with the traits of one parent or the other than offspring with recombinant-type traits.

Answer 2

When a testcross between f1 dihybrid flies produces more offspring with both traits like those of one parent, or the other than offspring with recombinant-type traits are produced means that the two genes are link. The reason that linked genes are inherited together is that they are located on the same chromosome.