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Degree: Medical Biochemistry (Bachelors) - Leeds University
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A mutation is any change to the base sequence of DNA.
The different types of mutations that can occur include:
Subsitution - this is where one base is swapped for another
Deletion - one or more bases are removed from the sequence
Insertion - one oe more bases are added to the sequence
Duplication - one or more bases are repeated
Inversion - a sequence of bases is reversed, for example if a sequence was ATAGC, then an inversion mutation would cause it to become CGATA
Mutations don't always necessarily cause changes to the primary structure as the amino acid code is degenerate (more than one base sequence codes for the same amino acid)
For example TAT and TAC both code for the amino acid Tyrosine, so if the T was substituted for a C it wouldn't make a difference to the primary structure.
However some mutations have a large effect on the base sequence. As the amino acid code is read in triplets, if a base is deleted or inserted it causes a frame shift, it changes the way the rest of the sequence is read.see more
The genotype of an organism is the alleles it has. while the phenotype is the characteristics the alleles produce.
For examples the alleles for hair colour could be BB for brown hair and Bb for blonde hair,
The genotype BB would mean the phenotype is a person having brown hair,
while the genotype Bb makes the phenotype a person with blonde hair.see more