BiologyDifferences

Difference Between Linkage and Crossing Over

Difference Between Linkage and Crossing OverIn eukaryotes, cross-linking and gene splicing are two separate but related phenomena. Crossing over is a phenomenon in which genes are exchanged in a germ line.

Genetic linkage is the tendency for genes to stay together on a chromosome.

Read on to find out how these two systems differ from each other and if they have anything in common.

Definition of Crossing Over vs. Linkage

  • Linkage: Closely positioned genes tend to get transferred together during gamete formation.
  • Crossing  Over: Exchange of genes from a pair of alleles between non-sister chromatids during gamete formation.

Effect of Distance Crossing Over: Distance between two genes is directly proportional to the possibility of crossing over.

Effect of Distance Linkage: Distance between two genes is inversely proportional to the degree of linkage.

What is Crossing Over?

When genes are exchanged from chromosomes to non-sibling chromosomes during gamete meiosis in sexual reproduction, it is called crossover It is the process of germline gene exchange or transfer of genes from a pair of alleles to ensure that the gamete receives a combination of genes. of both parents. This phenomenon was described in 1909 by Morgan.

What is Linkage?

During meiosis in sexual reproduction, the ability of several closely located genes or DNA sequences to be transmitted together on a chromosome is called linkage or genetic linkage These genes must be on the same chromosome.

This phenomenon is an exception to Mendel’s law of free variation and was discovered in 1905 by Bateson, Saunders and Punnett when they studied the color and shape of pollen and flowers in pea plants.

Difference Between Linkage and Crossing Over

Linkage Crossing Over
Ensures that the genes stay in a chromosome to inherit together Crossing over enables the separation of genes in a chromosome and separates it into various gametes
The strength of the genetic linkage between 2 genes is thought to be inversely proportional to the distance between them in the chromosome The probability of two genes crossing over is directly proportional to the distance between them in the chromosome
The strength of the linkage between 2 genes can increase if the distance between them decreases The probability of two genes crossing over decreases if the distance between them decreases
Ensures the continuity of the parental trait in the offspring Causes alternations in the parental traits in the offspring
Reduces the probability of variation through sexual reproduction Increases the probability of introducing variability in sexual reproduction

 

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