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GCSE Biology · key term
DNA that does not provide the amino acid sequence of a protein; some regions help control whether genes are expressed.
Used by AQA, Edexcel and OCR
Specification 4.6.1.5 · Paper 2
DNA that does not code for a protein; some of it controls whether genes are switched on or off.
Revise: Mutations and Gene Expression (Higher Tier)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 3.8B, 3.9B · Paper 1
For a complete description, state that the DNA unwinds, name RNA polymerase, identify its binding to the non-coding DNA in front of the gene, and explain that RNA nucleotides are joined to form complementary mRNA.
Build explanations as a complete causal chain: non-coding DNA variant → altered RNA polymerase binding → altered transcription → a different quantity of mRNA → a different quantity of protein → possible change in phenotype.
Do not say that non-coding DNA is useless. It does not code for an amino acid sequence, but regions of it can control whether and how strongly a gene is expressed.
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DNA that does not code for the amino acid sequence of a protein; the region in front of a gene provides the binding site for RNA polymerase.
Immediately in front of the gene is a region of non-coding DNA. It is described as non-coding because it does not code for the amino acid sequence of the protein. The enzyme RNA polymerase binds to this region, positioning it at the beginning of the gene.
DNA whose base sequence does not code for the amino acid sequence of a protein; some non-coding regions help control gene expression.
Specification B5.1b, B5.1e · Paper 2 (Foundation), Paper 4 (Higher)
DNA that is not part of a gene but is still part of the genome.
Revise: GenomeDNA is packaged into chromosomes, and an organism's genome includes the DNA across its chromosomes. It includes genes and non-coding DNA. So a gene is only part of the genome; a chromosome is a package of DNA, not another name for the whole genome.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
DNA that does not provide the amino-acid sequence for a protein; some of it regulates the expression of genes.
Revise: Non-coding DNA VariantsSome sections of non-coding DNA help control this activity. They do not provide the amino-acid sequence of a protein, but they can influence whether particular genes are expressed. This is why “non-coding” does not mean “having no function”.