Question

Explain briefly:
i. Vaccination
ii. Inbreeding Depression

Answer 1

• Vaccination: The principle of vaccination is based on the property of memory of the immune system. In the preparation of vaccine inactivated / weakened pathogens or antigenic protein of pathogen are introduced in the body. The antibodies produced in the body against these antigens would neutralize the pathogenic agents during actual infection. The vaccines also generate memory B and T- cells that recognise the pathogen quickly on subsequent exposure and overwhelm the invaders with a massive production of antibodies.

The first vaccination was performed by a young British Physician, Edward Jenner (1796) to protect people from small pox. Edward Jenner is regarded as “Father of Immunology”. The first true vaccine consisting of weakened micro-organism against chicken cholera was developed in 1880, by the French microbiologist, Louis Pasteur.

• Inbreeding Depression: Inbreeding refers to the mating to move closely related individuals within the same breed for 4-6 generations. The breeding strategy is an follows – superior males and superior female of the same breed and identified and mated pairs. The progeny obtained from such matings are evaluated superior males and female among them are identified for further mating. Inbreeding increases homozygosity. Thus inbreeding is necessary if we want to evolve pureline in any animal. Inbreeding exposed harmful recessive that are eliminated by selection process. It also helps in accumulation of superior and elimination of less desirable genes. However, continued inbreeding depression. Whenever this becomes a problem, selected animals of the breeding population should be mated with unrelated superior animals of the same breed. This usually helps restore fertility and yield.