Mutations Flashcards
What is a mutation?
A change in a DNA sequence that can be heritable and is also the process of changing the DNA sequence
What is a mutant?
An organism with a mutated gene that expresses a mutant phenotype
What are the two things that result in genetic variation?
Recombination and mutation
What are germline mutations?
A mutation that is in the gametes and can be passed on to offspring
What are somatic mutations?
A mutation in somatic cells that aren’t passed to offspring, results in a genetic mosaic which results in sections with a different genetic code
What are point mutations?
Mutations that only alter one nucleotide or a short sequence
What are the two types of base substitutions?
Transition and transversion
What is a transition mutation?
A purine is changed into another purine, or a pyrimidine is changed into another pyrimidine
What is a transversion mutation?
A purine is changed into a pyrimidine, or a pyrimidine is changed into a purine
What are insertions and deletions? What kind of mutations can they cause? What is the effect on the protein?
Addition or removal of a base pair or short sequence. Can result in a frameshift mutation and a completely unfunctional protein
What is affected by a mutation in the promotor region?
RNA polymerase binding and transcription
What are the 4 possible results for a mutation in the promotor region?
Overexpression
Knockdown
Knockout/null
Silent mutation
What are the 3 types of mutations that can result from a base substitution in the coding region of a gene?
Synonymous, missense, and nonsense
What are synonymous mutations? What affect do they have on the protein?
Silent mutation. A codon is changed, but because of redundancy the new codon encodes the same amino acid. It doesn’t affect the protein
What are missense mutations? What is the effect on the protein?
A change in an amino acid. Can be conservative and be changed into a chemically similar amino acid, or non-conservative and be changed into a chemically dissimilar amino acid. Conservative missense mutations have less of an effect on the protein than non-conservative missense mutations