Genes, Mutations Flashcards
Discontinuous
Can group, qualitative, small amount of genes, unaffected by environment.
E.g. Gender
Intraspecific Variation
Differences in organisms of same species
Species
Member of same species that can breed together to produce fertile offspring.
Environmental factors that affect phenotype
- pH
- light intensity
- skin tan
(Produce variation)
Genotype
Alleles
Phenotype
Way its presented
Mutation
Change in a nucleotide resulting in a changed base sequence which changes DNA.
Can be beneficial: more efficient enzyme.
Large section mutated: can be lethal: protein not expressed.
Affects tertiary structure: can’t function correctly.
A base Substitution
Replacement of one nucleotide with another nucleotide containing a different base.
A deletion
Loss of nucleotide
Frame shift
More effect as substitution affects one codon
Types of mutation
- A base substitution
- A deletion
No effect occurs in non-coding region of the DNA (intron)
- A different codon may produce the same AA (degenerate)
- The altered AA may not affect the proteins shape or function.
Mutations arise…
- Randomly through DNA replication in cell division
- By mutagenic agents
Mutagen
Anything that causes a mutation.
A mutagenic agent can increase the rate of gene mutation.
Continuous
Can’t group, a large number of genes, environment has most influence, usually quantitative.
E.g. Height
