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Practise

Question bank

Original exam-style questions, mapped to your syllabus. Answers are checked for mathematical equivalence and every attempt updates your mastery.

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12 questions

SA-AB-DR-0011 markL1 FoundationCalculatorEvidence

A DNA sample is 30% adenine. What percentage is guanine?

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0121 markL1 FoundationCalculatorReplication

Semi-conservative replication means each new DNA molecule

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0021 markL2 StandardCalculatorDNA structure

Adenine pairs with thymine by

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0031 markL2 StandardCalculatorReplication

The enzyme that unwinds DNA and breaks hydrogen bonds is

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0041 markL2 StandardCalculatorReplication

DNA polymerase joins nucleotides by forming

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0051 markL2 StandardCalculatorEvidence

In Meselson and Stahl's experiment, after one generation in ¹⁴N, all DNA was intermediate density. This ruled out

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0071 markL2 StandardCalculatorDNA structure

Which is a pyrimidine?

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0081 markL2 StandardCalculatorDNA structure

RNA differs from DNA in having

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0092 marksL2 StandardCalculatorDNA structure

A 10 base-pair DNA section contains 4 C–G pairs. How many hydrogen bonds hold the strands together?

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0101 markL2 StandardCalculatorReplication

On the lagging strand, Okazaki fragments are joined by

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0111 markL2 StandardCalculatorDNA structure

The two strands of DNA are antiparallel, meaning

Salam Academy Original Practice · Proposed mark scheme

SA-AB-DR-0062 marksL3 ExamCalculatorEvidence

¹⁵N DNA replicates for 3 generations in ¹⁴N. What fraction of molecules is hybrid?

Salam Academy Original Practice · Proposed mark scheme