Q.Mention any two ways in which single nucleotide polymorphism (SNPs) identified in the human genome can bring revolutionary change in biological and medical science.

The Human Genome Project

The Human Genome Project (HGP) was a mega-international project launched in 1990 (largely completed in 2003) with the goal of sequencing the entire human genome — about 3 × 10⁹ base pairs — and identifying all its genes.

Its primary aim was to generate two main types of maps:

• Genetic (linkage) maps — the relative positions of genes/markers on chromosomes based on recombination frequencies.
• Physical maps — the actual physical distances between markers, measured in base pairs.

Two main strategies were used: Expressed Sequence Tags (ESTs), focusing on the expressed (gene) portions, and Sequence Annotation (shotgun sequencing), sequencing the whole genome and then assigning function.

Salient findings: the genome contains roughly 20,000–25,000 genes; less than 2% codes for proteins; chromosome 1 has the most genes and the Y chromosome the fewest; and repetitive sequences make up a large fraction. …