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Commonly confused

DNA vs RNA

DNA is the master copy of the instructions; RNA is a working copy that carries a message from it. Same alphabet, different job.

DNA

Double-stranded, uses the sugar deoxyribose, and its bases are A, T, G, C. It is stable and stays in the nucleus as the permanent store of genes.

RNA

Usually single-stranded, uses the sugar ribose, and swaps T for uracil (U). It is short-lived and carries the gene's message to where proteins are made.

The trap

The quickest tests: DNA has thymine (T), RNA has uracil (U); DNA is double-stranded, RNA is usually single. Students also forget the sugar difference (deoxyribose versus ribose). If you see U, it is RNA.

Where this connects

RNA exists because the cell keeps its master DNA safe in the nucleus and sends out disposable copies to do the work. That copying step is transcription.

How the copy is made

Quick check

Which base is found in RNA but not in DNA?

  • AThymine
  • BUracil
  • CAdenine
  • DGuanine