Single Nucleotide Polymorphism (SNP)

Definition

A single nucleotide polymorphism (SNP) is a variation at a single position in a DNA sequence among individuals, where a single nucleotide (A, T, C, or G) is replaced by another. These small genetic variations can influence traits and disease susceptibility, and they play a crucial role in understanding genetic diversity in modern human populations, revealing how these populations have adapted to their environments over time.

5 Must Know Facts For Your Next Test

1. SNPs are the most common type of genetic variation in humans, with millions identified across the human genome.
2. They can occur in coding regions of genes, affecting protein function, or in non-coding regions, influencing gene regulation and expression.
3. SNPs are useful for studying population genetics because they can help trace lineage and migration patterns of human populations.
4. Certain SNPs are associated with predispositions to diseases such as diabetes, heart disease, and some cancers, making them important in medical research.
5. The frequency of specific SNPs can vary widely among different populations, reflecting the impact of natural selection and environmental factors on human genetic diversity.

Review Questions

• How do single nucleotide polymorphisms contribute to genetic diversity within modern human populations?
  • Single nucleotide polymorphisms contribute to genetic diversity by introducing variations at specific locations in the DNA sequence among individuals. This genetic variation is crucial for adaptation and survival as it can influence physical traits and disease susceptibility. By studying SNPs, researchers can identify patterns of genetic variation that highlight how different human populations have evolved in response to their environments.
• Discuss the implications of SNPs in understanding human health and disease susceptibility.
  • SNPs have significant implications for understanding human health because certain variants are linked to increased risks for various diseases. By identifying these associations through genome-wide association studies (GWAS), researchers can develop targeted therapies and preventive measures for conditions like heart disease and diabetes. This knowledge allows for personalized medicine approaches, where treatment strategies are tailored based on an individual's genetic makeup.
• Evaluate the role of SNPs in evolutionary biology and how they help track human migration patterns.
  • SNPs serve as important markers in evolutionary biology because they provide insights into the genetic relationships among populations. By analyzing the distribution and frequency of specific SNPs across different geographic regions, scientists can infer migration patterns and historical population structures. This information enhances our understanding of human evolution, as it illustrates how populations have adapted over time to varying environmental pressures, ultimately shaping the genetic landscape we see today.

Related terms

Genetic Variation: Differences in DNA sequences among individuals, which can manifest as SNPs and other types of mutations, contributing to the genetic diversity within a population.

Haplotypes: Groups of genes or SNPs that are inherited together from a single parent, often used to track genetic variations associated with diseases or traits.

Genome-Wide Association Studies (GWAS): Research approaches used to identify genetic variants linked to specific diseases or traits by scanning the genomes of many individuals for SNPs.