8.1 Gene Mutations Flashcards
What is a genetic mutation?
An alteration to a DNA base sequence - often spontaneous during DNA replication
What is an insertion mutation?
When one or more nucleotides are inserted into the DNA sequence
What is a deletion mutation?
When one or more nucleotides are deleted from the DNA sequence
What is a substitution mutation?
When one nucleotide in the DNA sequence is replaced by another
What is a duplication mutation?
When one or more nucleotides duplicate and repeat
What is an inversion mutation?
When a group of nucleotides are removed from the DNA sequence and flipped 180° before being rejoined
What is a translocation mutation?
When a group of nucleotides are removed from the DNA sequence and inserted into the DNA of a different chromosome
Which genetic mutations cause a frameshift?
Insertion
Deletion
Duplication
Translocation
Are mutations always harmful?
The change to amino acid sequence can result in a protein that has no effect on the organism. May be beneficial, which is basis for evolution and natural selection
What is a mutagenic agent?
Factors that increase the rate of genetic mutation
Give examples of mutagenic agents.
Chemical mutagens e.g. alcohol/benzene
Ionising radiation e.g. UV and x-ray
What is a stem cell?
Undifferientated cells that can become specialised and selfrenew
Give three types of stem cell.
Totipotent
Pluripotent
Multipotent
What is meant by totipotent?
Can develop into any cell type including the placenta and embryo
What is meant by pluripotent?
Can develop into any cell type excluding the placenta and embryo
