Gene Mutations

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GENE MUTATION,TYPES OF MUTATIONS
1. Gene Mutation

A Gene Mutation is defined as an alternation in the sequence of nucleotides in DNA. It can affect a single nucleotide pair or larger gene segments of a chromosome. Mutations cause changes in the genetic code which lead to genetic variation and the potential to develop disease. What causes Gene Mutation?

→ Gene mutations are most commonly caused as a result of two types of occurrences. 1. Environmental factors
Ex) chemicals, radiation, and ultraviolet light from the sun can cause mutations. 2. Errors made during mitosis and meiosis
→ Common errors that occur during cell division can result in point mutations and frame shift mutations. Mutations during cell division can lead to replication errors which can result in the deletion of genes, translocation of portions of chromosomes, missing chromosomes, and extra copies of chromosomes.

Genetic Disorders
→ Disorders can be caused by a mutation in a single gene, multiple gene mutations, combined gene mutation and environmental factors. Gene mutation can cause several diseases such as Sickle cell anemia, cystic fibrosis,Tay- sachs disease, hemophilia and some cancers. Gene Mutation could be categorized in 2 ways

1. Point Mutations (also called a Base-pair substitution) http://www.youtube.com/watch?NR=1&v=uQiGUAeh3TE&feature=endscreen This Mutation make changes in a single nucleotide base pair. Silent Mutation| This type of mutation does not change the protein that is to be produced although a change in DNA sequence occurs. It’s because multiple genetic codons can convert into code for the same amino acid. Amino acids are coded for by three nucleotide sets called codons.Ex)Amino acid arginine- coded by * CGT, CGC ,CGA and CGG. If the CGC is changed to CGA, the amino acid arginine will still be produced.| Missense Mutation| Missense Mutation modifies the nucleotide sequence so that a different amino acid is produced. This change...
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