Question

A herd of cattle is showing reduced fertility and productivity. Provide one reason and one suggestion to overcome this problem.

Answer 1

Hint: When animals undergo mating within the same population for many generations, the recessive genes in the parents will accumulate in the progenies, generation after generation. This results in the formation of lesser desirable characters in the animals, leading to economic losses.

Complete answer:
The reason for a herd of cattle showing reduced fertility and productivity by inbreeding depression. To solve the problem of inbreeding depression, the animals are selectively mated with other animals that have superior genes that produce desirable characteristics. This in turn helps in regaining fertility and productivity. For economic gain, cattle with high reproductive capacity and good production of milk are preferred. These characteristics in animals are expressed by the particular gene present in them. In inbreeding depression, the recessive genes in the parents will accumulate in the progenies, generation after generation. Therefore it is not beneficial for cultivators to carry on inbreeding for a longer period.

Note: -The desirable properties are brought in domestic animals with various different methods. Crossbreeding is one method where the organisms with superior characteristics are crossed with each other. This is a natural method carried out from the ancient period.
-Another method for increasing productivity is by genetically modifying the organisms. By the process of genetic engineering, genes with desirable properties are introduced into the host organism using artificial chromosomes. Due to ethical issues, GMOs are banned in several countries.
-Artificial chromosomes are human-made and some common examples are yeast artificial chromosomes (YAC) and bacterial artificial chromosomes (BAC).