Unit 1.4 Gene mutations Flashcards
What is a missense mutation?
A substitution mutation where one amino acid codon is replaced with another, meaning one amino acid will be changed from another in the protein chain
What is a mutagenic agent?
A substance which artificially increases mutation rate
What is a mutation?
A change in the DNA structure or composition which causes a change in the phenotype
What is an example of a missense mutation?
sickle cell disease
What is a nonsense mutation?
Also a substitution mutation where one nucelotide is replaced with a premature stop codon which results in a shorter protein
What is an example of a nonsense mutation?
Duchenne muscular dystrophy
What is a splice site mutation?
This mutation may alter the codons that trigger the removal of introns in translation, resulting in some introns being retained and/or some exons being excluded from the mature mRNA transcrip
What is an example of a splice site mutation?
Beta-Thalassemia
What is a deletion mutation? (FRAMESHIFT)
A nucleotide is removed from the sequence. This causes all the codons and therefore all the amino acids after the mutation to be changed
What is an example of a deletion mutation? (FRAMESHIFT)
Cystic Fibrosis
What is an insertion mutation? (FRAMESHIFT)
An extra nucleotide is added to the sequence. This causes all of the nucleotides and therefore all the amino acids after this mutation to be changed
What is an example of an insertion mutation? (FRAMESHIFT)
Tay-Sachs Syndrome