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Biology · Paper 2 · Foundation + Higher · B6

DNA, genes and the genome

Key ideas1 of 3

Zoom in on genetic material

Inside the nucleus, chromosomes contain DNA. DNA is a polymer with two strands arranged in a double helix. A gene is a small section of DNA on a chromosome. Do not confuse a gene with a whole chromosome.

A cell contains a nucleus; a chromosome is magnified into a DNA double helix, with a short section highlighted as a gene.

Next: Alleles, genotype and phenotype →
Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · B6. Fourteen core lessons, followed by two labelled Higher Tier lessons.

AQA Combined Science Trilogy 8464 · 4.6.1.3. Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.