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6.1 distinguish between mutations of chromosomes, including rearrangements changes in chromosome number, including trisomy, and polyploidy and mutations of genes, including base substitution frameshift

distinguish between mutations of chromosomes, including

Useful information

Mutagenesis is the process of producing a mutation.

A mutagen is a physical factor or a chemical substance that causes mutations. Gene mutations are caused by mistakes during DNA replication. The rate of these mistakes occurring is increased due to mutagens. Mutagens include:

  1. High energy radiation eg. Gamma rays, X-rays, ultraviolet (UV) rays.
  2. Chemicals such as mustard gas, Agent Orange, hydrocarbons in cigarette smoke and many industrial chemicals.

Genic mutations occur when the sequence of bases in a section of the DNA molecule is changed. There are two types of genic mutations:

Example
Original DNA :
CAG TAG GTA
 
Substitute copy :
CAG AAG GTA
(A has substituted the original T)
 
Original mRNA :
GUC AUC CAU
 
Original amino acids :
valine isoleucine histidine
 
Substitute mRNA :
GUC UUC CAU
 
Substitute amino acids:
valine phenylalanine histidine