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23 Cards in this Set
- Front
- Back
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What is a mutation? |
A random change in the base sequence of DNA |
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What could happen to the protein if a mutation occurs? |
It could code for a new protein, a non-functional protein or it could produce the same protein (have no effect) |
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What happens in a substitution? |
One or more bases are swapped for another |
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What happens in a deletion? |
One or more bases are removed, resulting in a frame shift |
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What happens in an addition? |
One or more bases are added/inserted, causing a frame shift |
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What happens in duplication? |
One or more bases are repeated |
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What happens in inversion? |
A sequence of bases is reversed |
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What happens in translocation? |
A sequence of bases is moved from one location in the genome to another. This could be movement within the same chromosome or movement to a different chromosome |
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Which base in a triplet would be least likely to alter the amino acid if it was affected by a mutation? |
The third base |
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What is it called if a mutation doesn't cause a change in the amino acid sequence? |
A silent mutation |
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How can silent mutations occur? |
The DNA code is degenerate, so some amino acids are coded for by more than one triplet code |
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Which types of mutations are unlikely to change the amino acid sequence? |
Substitutions and inversions |
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Which types of mutations have a large effect on the amino acid sequence? |
Additions, deletions and duplications |
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What is this effect known as? |
A frame shift |
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What are the base triplets following on from the mutation said to be? |
Downstream of the mutation |
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What is a mutagenic agent? |
Something which increases the rate of mutations |
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What are 4 types of mutagenic agents? |
Ultraviolet radiation Ionising radiation Chemicals Viruses |
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What is the first way a mutagenic agent can increase the rate of mutations? |
Chemicals called base analogs can substitute for a base during replication |
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What is an example of this? |
5-bromouracil can substitute for thymine and pairs with guanine instead of adenine |
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What is the second way a mutagenic agent can increase the rate of mutation? |
By altering bases, some chemicals can delete or alter bases |
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What is an example of this? |
Alkylating agents can add an alkyl group to guanine, changing its structure so it pairs with thymine instead of cytosine |
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What is the third way in which a mutagenic agent can increase the rate of mutation? |
By changing the structure of DNA. Some types of radiation can change the structure of DNA, causing problems during replication |
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What is an example of this? |
UV radiation can cause adjacent thymine bases to pair up |
