What is a single nucleotide polymorphism (SNP)?

What is a single nucleotide polymorphism (SNP)?

• A. A region of DNA that codes for multiple proteins
• B. The location on the DNA where a single nucleotide are different in different individuals
• C. A locus that changes many genes at once
• D. A protein that binds to DNA

Answer: (B)

A SNP is a single base in the genome that varies among individuals at the same location. In other words, at a given position, one person might have a C while another has a T, with the surrounding DNA sequence being the same. These tiny single-nucleotide differences are extremely common and can occur in coding regions, regulatory regions, or noncoding DNA. They’re valuable as genetic markers because they help distinguish genetic backgrounds and can be associated with traits or diseases when they fall in or near important genes. The other descriptions describe larger features: a region coding for multiple proteins isn’t about a one-base difference, a locus that changes many genes at once points to a broader structural change, and a protein that binds DNA is a functional molecule rather than a DNA sequence variant.

A SNP is a single base in the genome that varies among individuals at the same location. In other words, at a given position, one person might have a C while another has a T, with the surrounding DNA sequence being the same. These tiny single-nucleotide differences are extremely common and can occur in coding regions, regulatory regions, or noncoding DNA. They’re valuable as genetic markers because they help distinguish genetic backgrounds and can be associated with traits or diseases when they fall in or near important genes. The other descriptions describe larger features: a region coding for multiple proteins isn’t about a one-base difference, a locus that changes many genes at once points to a broader structural change, and a protein that binds DNA is a functional molecule rather than a DNA sequence variant.