Loading…
Loading…
GCSE Biology · key term
A version of a region of DNA whose base sequence differs from another version.
Used by AQA, Edexcel and OCR
Specification 4.6.1.5, 4.6.2.1 · Paper 2
A version of a DNA sequence produced by a change such as a mutation.
Revise: Mutations and Gene Expression (Higher Tier)Mutations occur continuously and can produce genetic variants. Whether a variant affects phenotype depends partly on where the change occurs: in DNA that codes for a protein, or in non-coding DNA that helps control a gene.
Specification 3.9B, 3.10B, 3.22, 3.23 · Paper 1
A difference in a DNA base sequence produced by mutation.
Revise: Non-Coding DNA VariantsA mutation in non-coding DNA produces a genetic variant of that region. If the variant occurs where RNA polymerase binds, the changed base sequence may affect how easily the enzyme can attach.
A version of a DNA sequence produced by a mutation; in a gene, it can form a different allele.
A version of a region of DNA whose nucleotide base sequence differs from another version.
Specification B5.1d, B5.1e, B5.2c · Paper 2 (Foundation), Paper 4 (Higher)
A version of a DNA sequence that differs from another version because a mutation has occurred.
Revise: Mutations and variantsThe changed version is a genetic variant: all genetic variants ultimately arise from mutations. Mutations can occur by chance when DNA is copied, and factors such as ionising radiation can also cause them. They do not happen because an organism needs a particular characteristic.
A version of a DNA sequence that differs from another version because of a mutation.
An alternative form or sequence of a region of DNA, produced originally by mutation.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
A different version of a gene, arising from a difference in its DNA sequence.
Revise: Genetic TerminologyA different version of a gene can also be called a genetic variant. The words are closely connected: allele refers to a version of a gene that an organism carries, while variant emphasises that its DNA sequence differs from another version.
A version or region of DNA whose nucleotide base sequence differs because a mutation has occurred.
A version of a section of DNA that differs in its base sequence because of mutation.
A version of a DNA sequence that differs from another version and arises through mutation.
A different version of a gene or another difference in DNA sequence.
An alternative form of a gene that may affect a person's inherited susceptibility to disease.
A region of DNA whose nucleotide base sequence differs from another version of that region.
An alternative version of a DNA sequence produced by mutation.
A version of a region of DNA that differs in its base sequence from another version.
A different form of a gene arising from a change in DNA.
Distinguish the origin of genetic variants from their redistribution: mutation creates new DNA variants, while sexual reproduction produces new combinations of existing alleles.
Link cause and outcome clearly: a mutation changes DNA, creating a genetic variant and therefore increasing the possible genetic differences within the population.
Write natural selection as a sequence: random mutation produces a genetic variant → the variant may affect phenotype → an environmental pressure gives some phenotypes an advantage → those individuals reproduce more successfully → the advantageous variant becomes more common over generations.
Create a free account to read GCSE Biology revision notes for your exam board and track your progress.