1.5 - Genome And Mutations Flashcards
What is the genome
A cells total genetic complement of DNA is called its genome
What is a gene
A sequence of bases that code for a protein
What is a mutation
A mutation is a random change in the genome that can result in no protein or an altered protein being expressed
Mutations are the only source of new alleles
What different ways can chromosome mutations occur
(TIDD)
Translocation
Inversion
Duplication
Deletion
What happens in a translocation chromosome mutation
A section of one chromosome breaks off and becomes attached to another chromosome
What happens in an inversion chromosome mutation
A section of chromosome breaks off and turns around before joining back. This reversed the sequence of genes
What happens in a deletion chromosome mutation
A section of the chromosome is removed and when it reforms the chromosome lacks certain genes
What happens in a duplication chromosome mutation
A segment of a chromosomes partner attaches along the first chromosome
What different ways can gene mutations occur
(SID)
Substitution
Insertion
Deletion
What happens in a substitution gene mutation
In a substitution mutation, one base in a codon is substituted for another
What can gene mutations be classed as and what are the effects of each
Silent - the same amino acid is produced
Missense - an altered protein is produced
Nonsense - a stop codon is created which means no protein is created
What happens in a deletion and insertion gene mutation
A nucleotide is deleted/inserted causing a frame shift. All amino acids after this point are altered
What is a splice site mutation
A splice sure mutation is one which substitutes, inserts or deletes nucleotides at a site where introns are normally removed from the primary mRNA
