Chapter 15: Mutations Flashcards
what is a mutation?
a change in the DNA sequence
what are the types of mutations?
point and frameshift
what is point mutation?
one nucleotide is changed to a different nucleotide
has the same number of nucleotides
what is frameshift mutation?
additional or deletion of at least one nucleotide
change the number of nucleotides
what are the types of point mutations?
silent, missense, nonsense
what are silent mutations?
the DNA sequence has been changed, but the new codon still codes for the same AA
a change in what base may not change the AA?
3rd base
what type of mutation?
one nucleotide has been changed to a different nucleotide
new codon codes for the same AA
silent
what type of mutation?
one nucleotide has been changed to a different nucleotide
new codon codes for the same AA
silent
what are missense mutations?
one nucleotide has been changed to a different nucleotide
new codon codes for a different AA
will silent mutations be functional?
yes- same function as before
will missense mutation be functional?
maybe, it would make a difference if it is in the active site and regulatory site
not make a huge difference when the AA is similar and it may work as a space holder
what is sickle cell anemia caused by?
point mutation in gene for hemoglobin=missense
what is nonsense mutation?
one nucleotide has been changed to a different nucleotide
new codon codes for a stop codon
new protein is shortened and missing some of its AA
will nonsense mutations be functional?
no, the protein is shortened
what type of mutation?
addition or deletion of at least one nucleotide
changes the number of nucleotides
frameshift
what are the types of frameshift mutations?
insertion and deletion
what is insertion frameshift?
additional of 1 or more nucleotides
what is deletion frameshift?
removal of one or more nucleotides
will frameshift mutations be functional?
no, many AA are changed because all codons are shifted over
where can mutations occur?
germ-line or somatic cells
what can mutations be?
harmful: cause changes in protein sequence or gene expression that leads to health problems
nuetral: no effect
beneficial: can have beneficial effect on health
mutations are the source of
new alleles