Question

Define inbreeding depression.

Answer 1

Hint: As the name suggests is the condition that occurs due to repeated inbreeding. The offsprings produced by repeated inbreeding have reduced fitness and are susceptible to various kinds of diseases.

Complete Answer:
- The reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals is called inbreeding depression.
- Biological fitness can be referred to as an organism's ability to survive and maintain the stability of its genetic material. Population bottlenecks often cause Inbreeding depression, higher the gene pool or genetic variation within a breeding population, lesser are the chances to suffer from inbreeding depression.
- Inbreeding depression can occur in most groups of organisms, it may vary across mating systems. Hermaphroditic species seem to exhibit lower degrees of inbreeding depression as compared to outcrossing species, the repeated cycles of inbreeding causes deleterious alleles to purge from populations.
- Inbreeding results in occurrence of more recessive traits expressing themselves, due to similar genomes of pair-mates. Recessive traits occur in an offspring only if it is present in both parents' genomes. The genetic similarity of the parents causes frequent occurrence of recessive traits in their offspring.
- Consequently, the closer the breeding pair is, greater will be the possibility of occurrence of homozygous, deleterious genes in the offspring, resulting in very unfit individuals. The fertility is also affected, offspring produced might be infertile. Example- mules.

Note: Inbreeding refers to the breeding among closely related individuals. Its repeated cycles causes inbreeding depression due to which individuals produced are biologically unfit and weak.