Module 6: Genetics Evolution and Ecosystems Flashcards
What is Mutation?
Mutation is a change to nucleotides of DNA which could result in the formation of a non-functional protein.
What is Gene Mutation?
Gene mutation is a change to DNA base sequence.
What are more likely to cause mutations?
Mutagenic Agents: These work by intefering with DNA replicaion during transcription e.g
-High energy radiation (UV light),
-Ionizing radiation (Gamma rays and X rays)
-Chemicals (carcinogens such as mustard gas and cigarette smoke).
What is an operon?
A cluster of genes under the control of a promoter.
What structural detail of a polypeptide is altered by gene mutations.
– The sequence of amino acids/ primary structure
What is a frameshift?
Frameshift is the addition or deletion of a base resulting in the subsequent codons to be altered.
Original:TAC TTC AGG TGG
Mutation:TAC TCA GGT GG
What type of mutation is this?
Deletion
Original:TAC TTC AGG TGG
Mutation:TAC ATT CAG GTG G
What type of mutation is this?
Addition
Original:TAC TTC AGG TGG
Mutation:TAC ATC AGG TGG
What type of mutation is this?
Substitution
What do transcription factors do?
Transcription factors control the expression of genes by controlling which gene is turned on or off during transcription.
What mechanism controls production of lactase ?
Lac operon.
How it is possible for a mutation to have no effect on the protein produced from that gene
– If the mutation occurs in the intron
– More than one codon codes for an amino acid/the genetic code is degenerate
– Some amino acids won’t alter the shape of the protein
What are the 3 types of point mutations?
– Substitution
– Insertion
– Deletion
What does the statement “the genetic code is degenerate” mean?
This means that more than one codon can code for an amino acid so point(substitution) mutations may have no effect and a nrmal functioning protein can still be made
What is a nonsense mutation?
This is when the protein that is being coded for is abruptly put to a stop so the polypeptide is no longer coded for.
What is a promoter
This is a DNA sequence where RNA polymerase binds to
What is an Operator?
This a DNA sequence where the repressor protein binds to