Unit 1 Topic 9 - Mutation Flashcards
State that gene mutations are changed in the base sequences of genes.
State that gene mutations can affect both the coding regions of a gene and the regulatory sequences that control gene Expression.
Describe the three types of gene point mutations (SID)
There are three types of gene mutations:
Substitution
Insertion
Deletion
Explain the term “frame-shift mutation” and explain how this affects the structure of a protein.
The deletion or insertion of a base creates a frame-shift mutation. This affects all the bases/ amino acids after the mutation.
Describe the effect of missense, nonsense, splice site & regulatory
- Missense
Results in one amino acid being changed for another. This may alter a proteins function. - Nonsense
Results in a premature STOP codon being produced which will result in the production of a shorter protein which is usually non-functional. - Splice site mutation
These can affect RNA splicing as the mutation alters the sequence that marks the start of an intro or Exon.
This can:
• Prevent the intron being spliced out so it is still present in the mature transcript.
• cause an Exon to not be included in the mature transcript. - Transcription regulator mutation
This can cause a gene to be permanently switched on.
This can lead to more protein being produced than normal.
Describe the effect of transcription regulator mutations
More protein is being produced than normal.
Explain the term diploid
Diploid is double the amount of chromosomes found in the sperm and egg
Explain the term haploid
Haploid is half the amount of diploid chromosomes
Explain the term homologous chromosomes
Homologous is 2 chromosomes per parents
Describe the four types of chromosomes structure mutation (TIDD)
Translocation
Inversion
Deletion
Duplication
Explain how a duplication mutation could lead to evolutionary change.
The large changes in gene sequences as a result of chromosome mutation often make them fatal
