Advanced Placement (AP) Biology Practice Exam

What is the relationship between linked genes?

1. They are always inherited independently

2. They are located on different chromosomes

3. They are inherited together because they are on the same chromosome

4. They can never recombine during meiosis

The correct answer is: They are inherited together because they are on the same chromosome

Linked genes are genes that are located on the same chromosome and tend to be inherited together during the process of meiosis. This tendency occurs because the physical proximity of the genes on the chromosome reduces the likelihood of them being separated by recombination, which is the exchange of genetic material between homologous chromosomes. Although linked genes can sometimes undergo recombination, occurring less frequently than genes located on different chromosomes, they are generally inherited as a unit due to their close proximity. In contrast, genes that are located on different chromosomes follow the principle of independent assortment during meiosis, leading to their separate inheritance. Therefore, linked genes do not adhere to this principle since they are situated on the same chromosome. Recombination can happen, but it does not occur to the same extent as it does for unlinked genes, which can swap genetic material freely. Thus, the fundamental characteristic of linked genes is that they are inherited together because of their location on the same chromosome.