Unit One - Key Area 4 Flashcards
What are mutations?
Mutations are changes in DNA that can result in no protein or altered protein being synthesised
Name the single gene mutations?
substitution, insertion and deletion.
What is a substitution mutation?
When one nucleotide is replaced with another
What is insertion?
when nucleotides are added
What is deletion?
when nucleotides are deleted
What can substitution mutations cause?
Missense mutations – result in one amino acid being changed for another. This may affect protein function.
Nonsense mutations result in premature stop codon being produced which results in a shorter protein.
Splice site mutations result in some introns being retained and/or some exons not being included in the mature transcript
What can insertion/deletion cause?
frame-shift mutation = cause all of the codons and all of the amino acids after the mutation to be changed. This has a major effect on the structure of the protein produced.
What are the 4 types of chromosome structure mutations?
duplication, deletion, inversion and translocation
What is duplication?
when a section of a chromosome is added from its homologous partner
What is deletion?
where a section of the chromosome is removed.
What is inversion?
Inversion is where a section chromosome is reversed.
What is translocation?
where a section of a chromosome is added to a chromosome, not its homologous partner.
