Genes A, B, and C are linked on a chromosome and found in the order A–B–C. Genes A and B recombine with a frequency of 8%, and genes B and C recombine at a frequency of 24%. For the cross a⁺b⁺c/abc⁺×abc/abc, predict the frequency of progeny genotypes. Assume interference is zero.

Key Concepts

Genetic Linkage

Genetic linkage refers to the tendency of genes located close to each other on a chromosome to be inherited together during meiosis. This is due to the reduced likelihood of recombination events occurring between them. Understanding linkage is crucial for predicting the inheritance patterns of genes, especially when calculating recombination frequencies.

Recombination Frequency

Recombination frequency is a measure of the likelihood that two genes will be separated during meiosis due to crossing over. It is expressed as a percentage, indicating the proportion of recombinant offspring produced. In this question, the recombination frequencies between genes A and B (8%) and B and C (24%) are essential for determining the expected genotype ratios in the progeny.

Interference

Interference is a phenomenon in genetics where the occurrence of one crossover event reduces the likelihood of another crossover occurring nearby. When interference is zero, as assumed in this question, the recombination events between linked genes are independent, allowing for straightforward calculations of expected genotype frequencies based on the provided recombination rates.