9.1 Mutations Flashcards
what is a mutation?
changes in DNA base sequences of chromosomes
when do mutations occur?
they spontaneously occur during DNA replication
what type of gene mutations are there?
base additions
base deletions
base inversions
base substitutions
what type of gene mutations cause a frame shift?
base additions and deletions
what happens in base substitution?
where one base is swapped for another
what is the impact of gene mutations?
it could change the order of bases in a gene sequence or a/a
why could it change and not would change (during gene mutations)?
genetic code is degenerate
so it could make a new triplet that still codes for the same a/a
what a/a can a gene mutations have an impact on?
an a/a that is involved in the formation of ionic/H/disulfide bonds
an a/a that is located away from the active site
what happens if there’s a mutation on an a/a that is involved in the formation of ionic/H/disulfide bonds?
it changes the shape of the active site
the enzyme function changes
what happens if there’s a mutation on an a/a that is located away from the active site?
the 3rd structure is unchanged
shape of the active site is not changed
no change to enzyme function
why will a single base deletion/addition lead to the formation of a non-functional protein?
it’s a frame shift mutation
has knock-on effect by changing how the genetic code is read (it’s non-overlapping)
all triplets are changed - change in a/a seq, after point of deletion/addition
affects the bonds - changes 3rd structure - change in function
what can a chromosome mutation be? (change in what?)
change in whole sets of chromosomes
change in number of individual chromosomes
when do changes in whole sets of chromosomes occur?
when organisms have three or more sets of chromosomes
what is the condition called when there are three or more sets of chromosomes?
polyploid (in plants)
when do changes in individual chromosomes occur?
when individual homologous pairs of chromosomes fail to separate during meiosis
