CBSE Class 9 Answered

It reduces the genetic pool and variation of the organism. So the possibility of perishing of the entire breed increases with a calamity like a disease or climate change This is due to the lack of variety, which means that none of the organisms can cope with the changed condition.

Also, continuous in-breeding and selective breeding of particular genes runs the risk of losing some of the other genes from the gene pool altogether, which is irreversible. This may lead to in-breeding depression, which causes reduction in fertility and productivity.

Some of the less desirable genes may get phased out during this selection process.