ScienceVerseLearning path: DNA
The concepts to learn before DNA, in order. Each step links to its page and, where one exists, its quiz.
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Your path
- CellDirect prerequisite
The basic structural and functional unit of all known living organisms. Every living thing is made of one or more cells, each bounded by a membrane and containing the machinery needed to grow, respond to its environment, and reproduce. Cells fall into two broad types: prokaryotic cells (such as bacteria), which lack a nucleus, and eukaryotic cells (such as those in plants, animals and fungi), which organise their DNA inside a membrane-bound nucleus.
- DNAYour goal
Deoxyribonucleic acid: the molecule that carries the genetic instructions used in the growth, development and reproduction of all known living organisms. DNA is shaped as a double helix of two strands, each made of a sugar-phosphate backbone with attached bases — adenine (A), thymine (T), guanine (G) and cytosine (C) — that pair specifically (A with T, G with C) to hold the two strands together. Its structure was determined by James Watson and Francis Crick in 1953, building on X-ray diffraction data produced by Rosalind Franklin and Maurice Wilkins.
Where to go next
Concepts that build directly on DNA:
- Evolution: The process by which populations of living organisms change in their heritable characteristics over successive generations. Charles Darwin and Alfred Russel Wallace proposed natural selection as its principal mechanism: individuals with heritable traits better suited to their environment tend to survive and reproduce more successfully, so those traits become more common in the population over time.