mutations Flashcards
what is a mutation
any change to a base sequence of DNA
when can mutations be caused
during DNA replication
what can the rate of mutations be changed by
mutagenic agents
what are the different types of mutations
substitution
deletion
addition
duplication
inversion
translocation
what is substitution
one or more base pairs are swapped for another
what is deletion
one or more bases are removed
what is addition
one or more bases added
what is duplication
one or more bases repeated
what is inversion
when a sequence of bases is reversed
what is translocation
a sequence of bases is moved from one location to another, it could be within the same chromosome or moved to a different one
what does the order of DNA bases in a gene determine
the sequence of amino acids in a particular polypeptide
what happens if a mutation occurs in a gene
the sequence of amino acids in the polypeptide it codes for could be changed
what do polypeptides make up
proteins
what could happen if their is a change in the amino acid sequence of a polypeptide
a change in the tertiary structure could occur which would mean that it wouldn’t work properly
what can some mutations increase
increase in the chance of getting some cancers
what can some mutations cause
genetic disorders
what is a hereditary mutation
a gamete that contains a mutation for a type of cancer or genetic disorder that gets fertilized. the mutation will be present in the new fetus formed
what does the degenerate nature of the genetic code mean
some amino acids are coded for by more than one DNA triplet
due to some amino acids being coded for by more than one DNA triplet what does this mean
not all types of mutations will always result in a change to the amino acid sequence of a polypeptide
what mutation types will almost always change the amino acid sequence of a polypeptide
additions
duplications
deletions
what cause a frameshift
caused by addition deletion and duplications
a mutation that changes the number of bases in the DNA code which causes the shift in the base triplets that follow so that the triplet code is read in another way
explain why a mutation in a polypeptide that makes up an enzyme could affect the enzymes function
the mutation could result in a change of shape of the enzymes active site
this may stop substates from being able to bind to the enzymes active site, leaving the enzyme unable to catalyse the reaction
