Question

In a population of 50,000 diploid individuals, what is the probability that a new neutral μtation will reach fixation?

a) 0
b) 0.5
c) 1
d) Not determinable

Answer 1

The predicted frequency of recombinant offspring in a test cross for two characteristics cannot exceed 50% due to Mendelian inheritance patterns and genetic linkage. If genes are on separate chromosomes, they assort independently, while genes close together on the same chromosome may show less than 50% recombinants.

Step-by-step explanation:

In a test cross for two characteristics, the predicted frequency of recombinant offspring cannot be as high as 60%. The correct answer to the student's question is option d. This is because, in genetics, the maximum frequency of recombinant offspring for two independent genes resulting from a cross is 50%. This is due to the fact that when two genes are on different chromosomes, assort independently, and there's random mating, the offspring phenotypic ratios follow Mendelian inheritance patterns. If the two genes are located very close together on the same chromosome and are linked, the percentage of recombinant types can be significantly less than 50%, potentially down to 0% if there is no crossing over between the genes. However, due to crossing over during meiosis, the recombination frequency for linked genes can vary up to approximately 50%, which is the expected outcome if the genes were on separate chromosomes and assorted independently.