Mutations Flashcards
define mutation
change in a nucleotide sequence
define mutagenesis
process of mutation generation
Name some exogenous mutagens
radiation
free radicals
mutagenic chemicals
anti cancer agents
Name some endogenous mutagens
DNA replication defects
transposable elements
spontaneous events
What are transposons?
specific DNA sequences that move around to random sites may alter gene expression or inactivate a gene
What does SNP stand for?
single nucleotide polymorphism
What is a transition ?
substitution of base of same type
What is a transversion?
substitution to base of different type
What does a deletion result in?
often frameshift if not a multiple of three
stop codon may not be read changing length of gene product
what does an insertion result in ?
framshift unless multiple fo three
stop codon again may no longer be recognised
What is a nonsense mutation?
SNP results in stop codon, non- functional shortened protein produced
Why may a change in the amount of gene product occur?
mutation occurs in regulatory element
What is a synonymous mutation?
silent / neutral
base change does no alter aa coded for
Name some chromosomal abnormalities.
deletion s duplication inversions substitutions insertions translocations
Explain robertsonian translocation
break at centromere very small p arm lost q arm fuse to form new chromosome 46 to 45 chromosomes possible problems in meiosis
