Linkage

Definition

Linkage describes the tendency of genes located close to each other on the same chromosome to be inherited together during meiosis. It can affect the assortment of traits observed in offspring.

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. The closer two genes are on a chromosome, the less likely they are to be separated by recombination during meiosis.
3. Linked genes can sometimes be separated by crossing over, which occurs during prophase I of meiosis.
4. Recombination frequency is used to map the distance between linked genes; a 1% recombination frequency equals one map unit or centimorgan.
5. Thomas Hunt Morgan first discovered linkage through his work with fruit flies, Drosophila melanogaster.

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Related terms

Crossing Over: Exchange of genetic material between homologous chromosomes during prophase I of meiosis.

Independent Assortment: Mendel's principle stating that alleles for different traits segregate independently during gamete formation.

Recombination Frequency: The percentage of recombinant offspring among the total; used to map distances between genes on a chromosome.