Mutation Flashcards
How do mutations occur
Spontaneously, randomly and rarely
What is a mutation
An alteration in an organisms DNA- either in quantity or structure
What is a single gene mutation
Alteration of the DNA nucleotide sequence
What are the types of single gene mutation
Deletion, insertion and substitution
What is deletion (single gene mutation)
One or more DNA nucleotides are deleted from a section of DNA
What is insertion
One or more DNA nucleotides are inserted into a section of DNA
What is substitution
A DNA nucleotide is substituted for another
What are chromosome structure mutations
Alteration in number or sequence of genes in a chromosome
What are the types of chromosome structure mutation
Deletion, duplication, inversion and translocation
What is deletion (chromosome structure mutation)
Detached genes are lost completely
What is duplication
Sets of genes from one chromosome becomes attached to a homologous chromosome- leading to repeated genes
What is translocation
Detached genes become attached to a different chromosome in the complement (i.e not the homologous partner)
What is inversion
Chromosome breaks in two places and a set of genes rotated through 180°
What are the types of substitution
Splice-site, missense and nonsense
What is splice-site
An intron may be included/exon not included in mature DNA
