CBSE Class 12-science Answered

Inbreeding is necessary if we want to develop a pure line in any animal. When breeding is between animals of the same breed for 4-6 genera­tions, it is called inbreeding.

Method of inbreeding:

• Inbreeding may be explained by taking an example of cows and bulls.
• Superior cows and superior bulls of the same breed are identified and mated.
• The progeny obtained from such mating are evaluated and superior males and females are iden­tified for further mating.
• A superior female, in the case of cattle, is the cow that produces more milk per lactation.
• A superior male is that bull, which gives rise to superior progeny as compared to those of other males.

Advantages of inbreeding:

• The process of inbreeding increases homozygosis.
• Inbreeding exposes harmful recessive genes that are eliminated by selection.
• It also helps in accumu­lation of superior genes and elimination of less desirable genes.

Disadvantages of inbreeding:

• Continued inbreeding reduces fertility and even productivity.