8.1 Mutations Flashcards
What is a mutation
A change in the base sequence of DNA
What are mutations caused by
Errors in DNA replication
What is a addition mutation
Where one or more bases are added to the DNA sequence
What is a deletion mutation
Where one or more bases are removed from the DNA sequence
What are substitution mutations
Where one or more bases are change in the DNA sequence
What are inversion mutations
Where the order of bases in the DNA sequence are inverted
What is a duplication mutation
Where one or more bases are duplicated in the DNA sequence
What is a translocation mutation
Where a section of DNA sequence is moved to another section of the DNA sequence
What can a mutation alter
The amino acid that the DNA encodes
If the amino acids in a protein are changed, what happens to the protein
The tertiary structure may be altered
What factor of the genetic code, means that a mutation may not effect the protein
Degenerate code
Why is DNA said to be degenerate
Some amino acids are encoded by multiple codons
What is the name of the process when all the base triplets downstream of the mutation are effected
Frameshift
What 3 mutations may cause a frameshift
- Insertion
- Deletion
- Duplication
What are the causes of mutations
- DNA replication
- Mutagenic agents
What are examples of mutagenic agents
- Ionising radiation
- Ultraviolet radiation
Explain how a single base subtitution causes a change in the structure of the polypeptide (3 marks)
- Change in (sequence of) amino acid(s)/primary structure;
- Change in hydrogen/ionic/disulfide bonds;
- Alters tertiary/30 structure;
What is a substitution mutation
- Replacement of a base by a different base (in DNA);
