4 What is the approximate number of genes in the human genom

4. What is the approximate number of genes in the human genome? (10 points)

Solution

The human genome is a typical eukaryotic genome comprising of heterochromatin and euchromatin regions. Out of total genome, only 1.5-2% region encodes for functional protein. Rest 99.5-98% of the genome encodes for accessory genes. Importantly, the human genome follows the universal rule of translation of proteins following the genetic codon dictionary. Following transcription and translation, it has been observed that the human genome encodes for nearly18000-20000 functional genes.

However, this number is supposed to reduce in near future. The reason for this decrease has been attributed to the fact that human/eukaryotic genome follows RNA splicing and post-translational modifications. Following these methodologies, even a single genetic sequence can encode for multiple types of proteins. Thus, the human genome need not carry gene for each and every protein it encodes. Thus, the number of total functional genes is further supposed to reduce.