Question

If, when counting the F1 progeny, you did not separate the two nonrecombinant (parental) progeny classes by gender, hypothetically, how many of each nonrecombinant class would then be present in those two groups?

Answer 1

If the two nonrecombinant (parental) progeny classes are not separated by gender, they would maintain a 1:1 ratio for both linked and unlinked genes, reflecting the parental genotypes without recombination.

Step-by-step explanation:

When considering the F1 progeny in Mendelian genetics and the inheritance of two genes, if we do not segregate the nonrecombinant, or parental, progeny classes by gender, the predicted frequency of offspring remains according to their genotypic combinations. For linked genes, the two nonrecombinant classes would both be present in a 1:1 ratio, assuming that there is no bias in the gender of offspring for those genotypes. However, in the case of unlinked genes, there should be a variety of gametes produced in equal frequencies according to the Mendelian concept of independent assortment, but still, the nonrecombinant classes of offspring would maintain a 1:1 ratio as they show the original parental allele combinations.

For example, in a test cross with one parent being heterozygous for two linked traits (AaBb) and the other homozygous recessive (aabb), the nonrecombinant offspring (AaBb and aabb) would each represent half of the total parental-type offspring. Nonrecombinant offspring reflect the genetic linkage and show the parental genotypes without recombination.