Mutation and The Phenotype

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  • Created by: tiacoles
  • Created on: 20-01-16 11:56
  • A mutation is an unpredictable change in the genotype of a cell that results from damage to, or imperfect replication of, the DNA, or from faulty operation of mitosis or meiosis. 
  • Can be a gene mutation or chromosome mutation.
  • Mutation is a rare event.
  • Mutation takes place in a single cell, but cannot usually be detected until the mutant cell is replicated and a distinctive phenotype has been produced. 
  • Some chemicals, mutagens, increase the chance of mutation because they react with DNA or interfere with replication. 
  • Some types of radiation, such as X-rays, cause mutation by damaging DNA. 
  • A gene mutation affects the nucleotide sequence of a section of DNA so that the triplet code for the primary structure (amino acid sequence) of the polypeptide coded by the gene is changed. 
  • One or more nucleotides may be deleted from, or added to, the sequence. This alters the reading frame of the triplet code, altering all subsequent triplet codes. 
  • One nucleotide may be substituted for another, producing a different triplet code which may code for a different amino acid or be


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