Point Mutation - Point Mutation 'Point mutation' covers a...

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Point Mutation 'Point mutation' covers a variety of sins from genuine single base pair changes to small deletions and insertions (which I have however placed in the next section). A single base pair change may have no genetic consequences whatsoever but, on the other hand, it may cause a dominant lethal effect. The first alternative is far more likely. Why? Because 95% of DNA is non coding and a single base change occuring within it is unlikely to have any effect. In addition, because of the degeneracy of the genetic code, many mutations occuring within the third base position in a codon will have no consequence to the amino acid encoded. The figure shows a short region of coding sequence with a variety of possible mutations. amino acid substitution A single amino acid change may be unimportant if it is conservative and occurs outside the active site of the protein. On the other hand it can have severe effects. The single substitution of valine for glutamic acid at position six of the beta-
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Point Mutation - Point Mutation 'Point mutation' covers a...

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