Question

Linkage can be further classified into complete linkage and incomplete linkage. This classification can be done on the basis of

• A. size of the linkage group
• B. number of genes included in the linkage group
• C. strength of linkage
• D. size of the genes

Answer 1

The correct option is C strength of linkage

Linkage refers to the grouping together of genes located on the same chromosome. It can be further classified into complete linkage and incomplete linkage based on the extent or strength of linkage.

In complete linkage, the genes that are located on the same chromosome are not separated during crossing over. They are treated as a single unit altogether and inherited as such over the generations. This results in only parental combinations in the progeny. No new combinations are seen.

In incomplete linkage, the genes tend to separate due to crossing over. This results in production of new combinations in the progeny apart from parental combinations. However, the percentage of new combinations is usually lesser than parental ones.

Size of genes, size of linkage groups or number of genes in a linkage group do not play any role in this classification.