Mutations Flashcards
What are gene mutations?
Changes in the base sequence?
What effect can a gene mutation have?
A change in the DNA base sequence could change the order of amino acids in a particular protein. This could alter the shape of a protein meaning it will no longer be able to carry out its function.
What is a substitution mutation?
A DNA base sequence is swapped for another.
Sometimes a substitution mutation has no effect. Explain why?
The genetic code is degenerate meaning that a different base triplet could still code for the same amino acid. This means that the amino acid sequence and shape of the protein won’t be altered.
What is a deletion mutation?
A base is deleted.
What effect does a deletion mutation have?
It will cause a frameshift meaning completely different amino acids will be produced as the number of bases will change.
What is a mutagenic agent?
A substance that increases the rate of mutations.
Where do chromosome mutations occur?
Errors during meiosis.
What is chromosome non-disjunction?
The failure of chromosomes to separate properly means one daughter cell produced in meiosis will have more than one copy of the chromosome. This leads to a zygote produced by the fertilisation of that cell having more than two copies of that chromosome.
