Biology- SNPs and Haplotypes

What does SNP stand for, and what is its definition?

SNP stands for Single Nucleotide Polymorphism. It is a difference in a single DNA nucleotide (bases), present in at least 1% of individuals in a population.

How common are Single Nucleotide Polymorphisms (SNPs) among individuals?

SNPs are the most common type of genetic variation among people, occurring approximately every 300 nucleotides on average. There are around 10 million SNPs in a person's genome.

Provide an example of how a Single Nucleotide Polymorphism (SNP) can manifest.

For instance, a population might have a cytosine (C) in a specific DNA section, but an SNP may replace this with a thymine (T) at the same location in DNA.

Where are SNPs mostly found and what role do they play?

SNPs are primarily found between genes and act as genetic markers. They help scientists locate specific genes related to traits and diseases in an individual's genome.

What impact do most SNPs have on health or development?

While most SNPs have no effect on health, some are crucial in studying human health. They can predict an individual's response to drugs, susceptibility to toxins, risks of developing diseases, and track disease gene inheritance within families.

What are the main limitations of Single Nucleotide Polymorphism (SNP) analysis?

Limitations are mainly technical, requiring large-scale and inexpensive SNP genotyping methods. Ensuring unbiased samples representative of the total population is also crucial.

How are SNPs associated with Crohn's disease?

Crohn's disease, an inflammatory bowel disease, has specific SNPs. For example, on chromosome 16, a certain SNP position (T:T, homozygous recessive alleles) indicates a 35X increased risk of Crohn's disease.

What is the term for SNP clusters that appear together on the same chromosome and why are they significant?

When several SNPs cluster on the same chromosome and are inherited as a block, they are known as haplotypes. This allows researchers to conduct large-scale studies on SNPs and human diseases.

What is the HapMap project and what information does it aim to catalog?

The HapMap project is an international collaboration cataloging common human genetic variations. It provides information on specific sites, their distribution frequency in different populations, and serves as raw material for linking genomics with diseases.

How are haplotypes relevant to koalas and what insight do they provide?

In koalas, 53 haplotypes have been isolated. This suggests that habitat fragmentation might have restricted gene flow between populations.