Mutations And Variations Flashcards
What is a mutation
A change in dna base sequence caused by mutagens - I.e. ionising radiation or specific chemicals
What are point mutations
Those that affect one nucleotide. Three types of variation include substitution, insertion and deletion.
Substitution - based changed to another base
Insertion - another nucleotide added
Deletion - taking away a nucleotide from sequence
Frameshift mutation is when the triplet code reading is disrupted. This occurs in insertion and deletion.
What are the effects of these mutations
Mutations can be neutral or silent: no effect
They can be Beneficial: enhanced function of protein
Finally they can be damaging: I.e. cancer. The protein is made but not functioning properly.
What are some extra types of mutations
Nonsense mutation: codon changed into stop codon. Protein has premature end so wouldn’t end
Misence mutation: particular amino acid A turned into amino acid B so degenerate code failed
Chromosomal mutation: mutations where large sections of chromosomes have been changed. I.e. deletion, duplication, inversion, translocation
