Question

Which of the following statements about animal breeding is incorrect?

• A. Cross-breeding allows desirable qualities of two different breeds to be combined
• B. Inbreeding exposes harmful recessive genes that are eliminated by selection
• C. Continued inbreeding, especially close inbreeding reduces fertility and productivity
• D. By inbreeding, purelines cannot be evolved

Answer 1

The correct option is D By inbreeding, purelines cannot be evolved

Inbreeding is the mating of closely related individuals (having common ancestors) within the same breed for 4 to 6 generations. It allows the desirable qualities of more closely related individuals to be continued within the same breed for 4-6 generations.

The closer an individual is related to another individual, the greater is the probability of sharing similar alleles. As a result, when closely related individuals interbreed, there is an increased probability that the offspring of the mating will receive the similar alleles from both the parents. Thus, inbreeding increases homozygosity. An individual homozygous for a particular character is said to be a pureline for that character and if a breeder intends to obtain purelines, inbreeding may be considered.

But it has been observed that continued inbreeding results in reduced fertility and productivity. This is called inbreeding depression.

Inbreeding also exposes harmful recessive genes that are eliminated by selection.

Cross breeding (mating between different breeds) allows the desirable qualities of two different breeds to be combined. The hybrid progeny is commercially superior to the parent.