DNA
A long molecule shaped like a twisted ladder that carries the instructions for building and running a living thing.
Last updated
Analogy
A very long recipe book written in a four-letter code.
In practice
Police use DNA from a hair or drop of blood to identify who it came from.
Practice
Flashcards
- What shape is DNA?A double helix, like a twisted ladder.
Questions people ask
What does DNA stand for?
DNA stands for deoxyribonucleic acid. It is made of two long strands twisted into a double helix. Each strand has a chain of units called bases: A, T, C and G. The order of these bases is the code. A always pairs with T, and C pairs with G.
Where is DNA found in a cell?
In animal and plant cells, most DNA is inside the nucleus, packed into chromosomes. Some is also in mitochondria, and in plants, in chloroplasts. In bacteria there is no nucleus, so the DNA floats loose in the cytoplasm, often with extra small rings called plasmids.