Concept Of Microbial Genomics

Non-coding regions: Single nucleotide polymorphisms (SNPs) are variations in a single nucleotide base, and they are most frequent in non-coding regions of DNA. These regions do not directly code for protein and are less subject to selection pressure, thus allowing more variation. Coding regions: SNPs in coding regions may cause mutations. Regulatory regions: Regulatory regions are also quite important for gene regulation, and the SNPs there may also have some kind of impact on gene expression. Exonic regions: Exons refer to the protein-coding sections of a gene.

Assertion (A): Some experts have posited the possibility of the human genome containing more than 30,000 genes based on preliminary estimates and expected complexity of the system. As the human genome project progressed, they realised the actual number of genes was less than initially anticipated. Reason (R): The reason is correct because it is true that *in silico* gene prediction is not fully reliable, especially with respect to non-coding regions and smaller genes. This has often resulted in a discrepancy between theoretical predictions and actual findings. Explanation: Since both are true, and Reason (R) provides a valid justification for the assertion, (A) is the correct option.