What is gene linkage?

• A. When genes are located far apart on a chromosome.
• B. When genes are on separate chromosomes.
• C. When closely located genes are inherited together.
• D. When genes are influenced by external factors.

Answer: (C)

Gene linkage refers to the phenomenon where genes that are located in close proximity to each other on the same chromosome tend to be inherited together during meiosis. This is due to the fact that when chromosomes are duplicated and then segregate into gametes, closely linked genes are less likely to be separated by the process of crossing over, which can occur during prophase I of meiosis.

Because they are close together, the physical distance between them reduces the probability of recombination events occurring between those genes. As a result, offspring may inherit a group of genes that are closely linked rather than a mix of different alleles for those genes. This concept is crucial in genetics because it helps explain patterns of inheritance and can affect trait expression in organisms.

This understanding contrasts with scenarios where genes are located far apart on a chromosome or are situated on separate chromosomes, as these situations would lead to independent assortment, where alleles for different traits segregate independently of one another.