DNA — Science definition

The long molecule whose sequence carries genetic information; about two metres of it is packed into a nucleus six micrometres across.

Where it is taught

In use

Every cell in your body — a nerve cell in your spine, a cell lining your gut, a muscle cell in your calf — carries the same DNA, and they behave nothing alike.

DNA, Genes & Chromosomes

Questions using dna

Problem 1

Why is “DNA letters directly become an eye color” incomplete?
Answer and explanation

Genetic information affects cellular products and processes; traits emerge through those processes and often involve several influences.

Problem 2

Illustrative draft places a chromosome inside one gene and says every body cell with the same DNA performs the same task. Repair the nested relationship and explain cell specialization without inventing separate inherited genomes for every cell type.
Answer and explanation

Gene regions are parts of chromosome DNA, not containers for whole chromosomes. Cells with broadly similar genetic information can use different portions and develop different structures and roles. The model does not show every gene, product, or interaction, so a shared genome does not imply identical activity in all cells.

Place gene regions along chromosome DNA.

Connect information use with functional products.

Distinguish shared information from identical activity.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 3

How can two cells with similar DNA have different functions?
Answer and explanation

They can use different parts of the information and develop different structures and cellular activities.

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Elsewhere

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