Question

What is the main significance of linkage?

Answer 1

Hint:Male and female gametes are formed during sexual reproduction. Sexual reproduction occurs in the generation of kids that are not similar to their parents due to the fusing of male and female gametes. The independent assortment of genes, in which allelic genes segregate and assort independently, is in stark contrast to linkage.

Complete answer:
Linkage refers to the close linkage of non-allelic genes on a chromosome that allows them to be inherited as a unified block rather than as discrete pieces. Linkage occurs when two or more genes are found in a linear order on the same chromosome. Merely the dominant gene, only excessive genes, or a combination of both may be involved in the linkage.
Significance of linkage- Breeders are unable to combine beneficial characteristics in a single variety because of linkage. Plant and animal breeders find it challenging to mix different traits because of this.
Linkage helps to keep parental features together by reducing the probability of gene recombination. As a result, it aids the organism in maintaining parental, racial, and other characteristics.
Significance of crossing over- In sexually reproducing species, this process supplies an infinite source of genetic variety.
Plant and animal breeders make use of useful recombinations. Breeders aim to break up the links via crossing-over to produce progeny with a mix of valuable features.
This procedure results in a new gene combination (recombination).

Note:
Classification of linkage-
Based on genes involved: The coupling and repulsion linkages are the two types of connectivity. The linkage between dominant genes and excessive genes is known as coupling linkage. The linkage between dominant and recessive genes is known as repulsive linkage.
Based on chromosomes involved- Autosomal and sex chromosomal linkage are two types of linkage.
Based on crossing over- There are two forms of linking: complete and imperfect linkage.
There is no crossing over and no gene combinations in full linkage. However, in the case of inadequate linkage, choosing over may occur, resulting in the formation of no parental gene combinations.