OCR A Level Biology - Cellular control
What are the three types of mutation?
Substitution
Insertion
Deletion
What feature of the DNA molecule is changed as a result of mutation?
Sequence/ order of bases/ nucleotides
What are the three types of substitution mutation?
Silent
Missense
Nonsense
What is a point/ substitution mutation?
One nucleotide replaces (is substituted for) another
What is an addition mutation?
One or more nucleotides are added to the base sequence
What is a deletion mutation?
One or more nucleotides are removed from the base sequence
What is a nonsense mutation?
Amino acid is changed to a stop codon causing protein to be truncated
What is a missense mutation?
A different amino acid is coded for
What is a silent mutation?
A substitution that does not change the amino acid
, What is a frameshift?
When 1 or 2 nucleotides are deleted or inserted
Which types of mutations can cause a frame shift?
Insertion and deletion
What can a frameshift lead to?
A non-functional protein being produced
What are the possible effects of mutations?
Beneficial
Neutral
Harmful
Why do some mutations have a neutral effect?
The genetic code is degenerate and so not all mutations change the amino acid being coded for
The protein is unchanged
Give an example of a neutral mutation
Tongue rolling
Why do some mutations have a harmful effect?
They can change the structure of the protein, making it less functional
Give two examples of harmful mutations
Huntington's
Sickle cell anaemia
Why do some mutations have a beneficial effect?
They can change the structure of the protein, making it more functional
At what stages is gene expression controlled?
Transcription
Post-transcription
Post-translation
What are the three types of mutation?
Substitution
Insertion
Deletion
What feature of the DNA molecule is changed as a result of mutation?
Sequence/ order of bases/ nucleotides
What are the three types of substitution mutation?
Silent
Missense
Nonsense
What is a point/ substitution mutation?
One nucleotide replaces (is substituted for) another
What is an addition mutation?
One or more nucleotides are added to the base sequence
What is a deletion mutation?
One or more nucleotides are removed from the base sequence
What is a nonsense mutation?
Amino acid is changed to a stop codon causing protein to be truncated
What is a missense mutation?
A different amino acid is coded for
What is a silent mutation?
A substitution that does not change the amino acid
, What is a frameshift?
When 1 or 2 nucleotides are deleted or inserted
Which types of mutations can cause a frame shift?
Insertion and deletion
What can a frameshift lead to?
A non-functional protein being produced
What are the possible effects of mutations?
Beneficial
Neutral
Harmful
Why do some mutations have a neutral effect?
The genetic code is degenerate and so not all mutations change the amino acid being coded for
The protein is unchanged
Give an example of a neutral mutation
Tongue rolling
Why do some mutations have a harmful effect?
They can change the structure of the protein, making it less functional
Give two examples of harmful mutations
Huntington's
Sickle cell anaemia
Why do some mutations have a beneficial effect?
They can change the structure of the protein, making it more functional
At what stages is gene expression controlled?
Transcription
Post-transcription
Post-translation
