A-LevelBiologyNucleic acids and protein synthesisOct/Nov 2025Paper 1 Q241 Mark
The flow diagram shows some of the stages in the replication of a lagging strand of DNA. [Flow diagram: 'The DNA double helix begins to unwind.' -> 'The single strands of DNA are exposed.' -> 'New complementary DNA fragments are synthesised in the 5' to 3' direction.' -> 'The fragments of newly formed DNA are linked together.'] Which stage of DNA replication uses the enzyme DNA ligase?
AThe DNA double helix begins to unwind.
BThe single strands of DNA are exposed.
CNew complementary DNA fragments are synthesised in the 5' to 3' direction.
DThe fragments of newly formed DNA are linked together.
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The correct answer is D. This question tests the candidate's understanding of nucleic acids and protein synthesis within the Biologysyllabus. The examiner's mark scheme requires...
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