Mutations Flashcards
What is a mutation
Changes in the DNA that can result in no protein or an altered protein being made
What is a genetic disorder
A condition or disease that can be shown to be directly relevant to the individuals genotype. Genetic disorders may be disabling or even lethal
What are the single gene mutations
Substitution, insertion, deletion (SID)
What is substitution
A mutation when a nucleotide is swapped/replaced by another
What is insertion
A mutation where a nucleotide is added
What is deletion
A mutation where a nucleotide is deleted
What is a missense mutation
Changes only one amino acid which may result in a non-functional protein or have little effect on the protein
What is a nonsense mutation
Results in a premature stop codon being produced which results in a shorter protein.
What is a Splice-slice mutation
Result in introns being retained and/or some exons not being included in the mature transcript
What are frame shift mutations
They alter the sequence in which the bases are read and therefore change every amino acid after mutation, insertion and deletion are frame shift mutations
What are chromosome mutations
Involves changes to large quantities of DNA (one or more genes)
What is translocation
Where a section of a chromosome is added to a chromosome not its homologous partner
What is inversion
Where a section of a chromosome is reversed/turned 180*
What is deletion in chromosome mutations
Where a section of s chromosome is removed which leads to s shorter chromosome lacking many genes
What is duplication
Where a section of a chromosome is added from its homologous partner which results in the chromosome having an extra set of genes
Effect of chromosome mutations
Quite often have a lethal effect because so many genes are affected and do not function
Why are mutations important to evolution
It’s the only source of new alleles which causes variation between members of the same species and allows the best adapted organisms to cope with changes in their environment
What are favourable mutations
Mutations that make an organism better suited to its environment and increases chances of survival and are more likely to live long enough o breed and pass on these favourable genes
Importance of chromosome duplications
Allow potential beneficial mutations to occur in a duplicated gene whilst its original gene can still be expressed to produce its protein