Mutations Flashcards
Population
a group of organisms of the same species living together in a particular place at a particular time
Gene pool
The sum of all the alleles in a given population
Allele frequencies
how often each allele of a gene occurs in the gene pool for that population
Mutation
A change in a gene or a chromosome leading to a new characteristic in an organism - a permanent change in the DNA.
Mutant
A characteristics resulting from a mutation
Two types of Mutations
Chromosome; when all or part of a chromosome is affected.
Gene mutation; Changes in a single gene so that traits normally produced by that genes are changed or destroyed.
Mutagenic agents
Known to increase the rate of which mutations occur. E.g. X-rays, mustard gas etc.
Gene mutations
A change in the bases of the DNA could change the amino acid and could alter the protein. Could have no affect or prevent the protein from being produced.
Types of mutation
Induced; a mutation caused by a mutagenic agent
Spontaneous; A mutation that occurs due to an error in the natural biological process
Heritability of the mutation
Somatic; A change occurring in the gene in the body cell.
Germline; a change in the heredity material in the egg or sperm that becomes incorporated into the DNA of every cell in the body
Effects of Mutation
Missense Mutation; A change in the amino acid and therefore the protein that is produced
Non-sense Mutation; A change in the base sequence that results in a STOP of the code. Therefore synthesis will stop and shorter proteins are produced.
Neural Mutation; A mutation that causes a change in the amino acid, however does not cause a change in the overall protein produced
Silent Mutation; A mutation that does not change the sequence of the amino acid
Extent of mutations
Chromosomes mutations affect a whole number of genes whereas Gene mutations only affect a singular gene.
Change in DNA (Nucleotide)
- insertion - A new nucleotide is added to the DNA strand
- Substitution - An existing nucleotide is replaced with another
- Deletion - A nucleotide is removed from the DNA strand
Point mutations
A change in just one of the bases in a DNA molecule
Frame shift mutation
Occurs when bases have been added or removed. This results in a series of bases that codes for an amino acid starting at a different base. They affect the outcome for all the DNA from that point on.