Why does more crossing over occur between two distantly linked genes than between two genes that are very close together on the same chromosome?

Key Concepts

Crossing Over

Crossing over is a genetic process that occurs during meiosis, where homologous chromosomes exchange segments of genetic material. This exchange increases genetic diversity in gametes. The frequency of crossing over between two genes is influenced by their physical distance on the chromosome; genes that are farther apart are more likely to undergo crossing over.

Genetic Linkage

Genetic linkage refers to the tendency of genes located close to each other on the same chromosome to be inherited together. When genes are closely linked, the likelihood of crossing over occurring between them is reduced, leading to less genetic variation. Conversely, distantly linked genes have a higher chance of being separated during crossing over.

Recombination Frequency

Recombination frequency is a measure of how often crossing over occurs between two genes during meiosis. It is expressed as a percentage and is directly related to the physical distance between genes on a chromosome. A higher recombination frequency indicates that genes are farther apart, while a lower frequency suggests they are closer together, affecting their inheritance patterns.