Biology 9700 · AS & A Level · Protein synthesis

Protein synthesis — practice question

The two DNA strands are joined by hydrogen bonds formed between complementary base pairs.
(a)[4]

Explain why the hydrogen bonding between the two strands of DNA is important for it to perform its functions.

(b)[1]

Name processes $P$ and $Q$ shown in Fig. 4.1, where process $P$ changes DNA into mRNA and process $Q$ changes mRNA into a polypeptide.

(c(i))[2]

Suggest why it is significant that DNA is very stable.

(c(ii))[2]

Suggest why it is significant that mRNA is highly labile.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Hydrogen bonds are essential for the molecule’s 3-D shape” …

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