Linkage

Definition

Linkage refers to the tendency of genes located close together on a chromosome to be inherited together during meiosis. This phenomenon can affect the assortment of traits and complicate Mendelian inheritance patterns.

5 Must Know Facts For Your Next Test

1. Linkage violates Mendel's Law of Independent Assortment because linked genes do not assort independently.
2. Linked genes are located on the same chromosome and tend to be inherited together unless crossing over occurs.
3. The closer two genes are on a chromosome, the less likely they are to be separated by crossing over during meiosis.
4. Genetic linkage can be measured using recombination frequency; a lower frequency indicates stronger linkage.
5. Linkage maps (or genetic maps) can be created by calculating recombination frequencies between different genes.

Review Questions

• How does genetic linkage violate Mendel's Law of Independent Assortment?
• What is the relationship between the distance between two genes on a chromosome and their likelihood of being separated by crossing over?
• How is recombination frequency used in creating linkage maps?

Related terms

Crossing Over: The exchange of genetic material between homologous chromosomes during meiosis, leading to new combinations of alleles.

Recombination Frequency: A measure of how often crossover occurs between two genes, used to infer their physical distance on a chromosome.

Genetic Map: A representation showing the relative positions of genes on a chromosome based on recombination frequencies.