CBSE Class 12-science Answered

Significance of linkage:

• Linkage does not permit the breeders to bring the desirable characters in one variety. For this reason, plant and animal breeders find it difficult to combine various characters.
• Linkage reduces the chance of recombination of genes and thus, helps to hold parental characteristics together. It thus helps organism to maintain its parental, racial and other characters.

Significance of crossing over:

• This process provides an inexhaustible store of genetic variability in sexually reproducing organisms. 
• Useful recombinations are used by the plant and animal breeders. Breeders try to break up the linkages by crossing-over to get combinations of useful traits in the progeny. 
• This process produces a new combination of genes (recombination).