Human Cells: Mutations Flashcards
(14 cards)
What are mutations?
Changes in DNA that can result in absence of protein or production of an altered protein
What do single gene mutations involve?
The alteration of a DNA nucleotide sequence as a result of the substitution, insertion or deletion of nucleotides
What do nucleotide substitutions give rise to?
Missense, nonsense and splice-site mutations
Missense mutations result in what?
One amino acid being changed for another. This can give a non-functional protein or have little effect on the protein.
Nonsense mutations result in what?
A premature stop codon being produced, which gives a shorter protein
What do splice-site mutations result in?
Some introns being retained and/or some exons not being included in the mature transcript
Nucleotide insertions and deletions result in what?
Frame-shift mutations
What do frame-shift mutations 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 that is produced
What do chromosome structure mutations that involve changes to the structure of a chromosome involve?
Duplication, deletion, inversion and translocation
When does duplication happen?
When a section of a chromosome is repeated
What happens in deletion?
A secretion of chromosome is removed
What happens in inversion?
A section of chromosome is reversed
When does translocation happen?
When a section of a chromosome is added to a chromosome, not its homologous partner
The substantial changes involved in chromosome mutations often make them what?
Lethal
