Question

The total number of genes in humans is far less $(<25,000)$ than the previous estimate (upto 1,40,000 genes). Comment.

Answer 1

Genes in the human genome:

Less than 2 percent of human genome codes for proteins. Earlier it was estimated that there are upto 1,40,000 genes present in the human genome.

After the human genome project, this number has been reduced to 30000 genes.

Reason for less number of genes:

Reason for less number of genes in humans:

● Human genome has a lot of non-coding repetitive sequences which do not code for proteins and hence, do not contribute to genes. Yet, these repetitive sequences are important for techniques such as DNA fingerprinting, maintaining chromatin structure and its dynamics.

● Promoter, terminator and other regulatory sequences of DNA are also not part of the gene, still important for the proper functioning of a gene. Together, these sequences make up the large proportion of non-coding regions of DNA.