The Ladder, and Which Bonds Are Which

You'll learnwhich bond builds DNA's chain, which bond lets it open, and why RNA differs.

Heredity is a ladder: two covalent chains that never let go, and rungs of hydrogen bonds that let go on purpose, because a message you cannot open is not a message. Twelve short steps; press Next for each one.

12 STEPS · 6 QUICK CHECKS · BACKBONE = COVALENT · RUNGS = HYDROGEN BONDS · NEW STRAND 5′→3′ · v6

one covalent chain · hydrogen-bond rungs · a strand with a direction

Before you start

What you're looking at

The DNA ladder, taken apart: sugars, phosphates, bases, and the two kinds of bond that hold them.

The question

Which bond keeps the archive intact, and which bond lets a cell open it?

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