Chapter 12 Flashcards
DNA mutation
An inheritable change in DNA sequence
The change of a single base pair is known as
point mutation
where one purine-pyrimidine base pair is exchanged for another purine-pyrimidine pair (C≡G becomes T=A or vice versa)
transition mutation
where a purine-pyrimidine base pair is replaced with a pyrimidine-purine base
pair, or vice versa (ex: C≡G becomes either G≡C or A=T).
transversion mutation
does not change any amino acid in the protein (due to the redundancy of codons).
silent mutation
a point mutation generating a change in a single amino acid. [example: glutamate
(GAA) to glutamine (CAA) exchange]
missense mutation
induces instead of an amino acid codon, a stop codon. This generates a truncated
protein.
nonsense mutation
Mutations are incorporated in how many steps
two-step process
A mutation caused by insertion of one or more extra bases between successive bases in DNA.
insertion mutation
A mutation resulting from the deletion of one or more nucleotides from a gene or chromosome. Compare insertion mutation.
deletion mutation
A collective term for insertion and deletion mutations
indels
A mutation caused by insertion or deletion of one or more paired nucleotides, changing the reading frame of codons during protein synthesis; the polypeptide product has an altered amino acid sequence beginning at the mutated codon.
frameshift mutation
The duplication of a large tract of DNA, leading to an increased dosage of genes in the affected area.
duplication mutation
A mutation that results from the inversion of a large segment of DNA in a chromosome.
inversion mutation
A mutation that results from the exchange of large segments of DNA between nonhomologous chromosomes.
translocation mutation
causes of indels
- abberant recombination
- template slippage by dna polymerase
The enzymatic removal of amino groups from biomolecules such as amino acids or nucleotides
deamination
