Genetics And Evolution Flashcards
Define a mutation
Change in the amount or the structure of DNA of an organism
How can a phenotype be passed on?
Through mitosis and meiosis
Define somatic mutations
Mutations passed on to daughter cells and inherited
Define a gene mutation
Change in nucleotide sequence
Define a chromosome mutation
Change in several genes effecting am area on a chromosome. Can be structural changes on DNA
What is translocation in mutation?
New / extra genes
What is duplication in mutation?
Some genes are copied
What is deletion in Mutations?
Some genes are lost
What is inversion in mutation?
Genes are removed and rearranged facing backwards
What is substitution in point mutation?
One base changes to another
What is insertion in point mutation?
Adds a base to sequence causing the sequence to shift
What is deletion in point mutation?
Removal if a base causing a change in sequence
What is frame shift in Mutations?
Amino acids chain shifts due to insertion
What are the 3 results of substitution Mutations?
Coded for the same amino acids
Codes for different amino acids
Codes for a stop codon
What are the effects of Mutations?
Phenotype may not be effected
Different R groups change amino acid
Protein can become shorter
Could lead to an advantageous phenotype eg lactose tolerance
Name some diseases caused by Mutations
Cystic fibrosis
Sickle cell anaemia
Name some beneficial mutations
Lactose tolerance
Bacteria resistance
Name some neutral Mutations
Dimples
Free ear lobes
Define a mutagen
Biological, chemical or physical factors that cause a mutation
Name an example of a mutagen
Ionising UV radiation- break strands of DNA
Viruses- DNA of foreign body may change organisms genome
What can chromosome Mutations cause?
Developmental problems
When do structural changes to chromosomes occur?
Prophase 1