What is the expected outcome when genes are located close together on a chromosome?

When genes are located close together on a chromosome, the expected outcome is a lower recombination frequency. This phenomenon occurs due to the physical proximity of the genes, which reduces the likelihood that they will be separated during the process of recombination, also known as crossing over, that occurs in meiosis.

During recombination, homologous chromosomes exchange portions of their genetic material. If two genes are located on the same chromosome and are too close to each other, the chances of crossing over happening between them is decreased. As a result, offspring are more likely to inherit the two genes together, leading to a lower recombination frequency.

In contrast, genes that are located far apart on a chromosome have a higher chance of being separated during recombination, resulting in a higher recombination frequency. In situations where genes are extremely far apart or on different chromosomes, recombination can occur independently, which would also increase the frequencies of different allele combinations in offspring. Thus, the proximity of genes is key to understanding their recombination behavior.