OCR ASH020Frequently examined

Biology A H020: Nucleotides and nucleic acids Topical Past Paper Questions

OCR AS Biology A (H020) past-paper questions on Nucleotides and nucleic acids, free. This topic is frequently examined across 5 exam sessions. Sign in for the full topic-segregated question bank and AI worksheets.

Sample questions

Summer (May/Jun) 2024· 1

DNA has a double helix structure made from polynucleotides. (a) Describe how a polynucleotide is formed from its monomers. [1] (b) DNA is replicated during interphase of the eukaryotic cell cycle. (i) The enzyme helicase is active during DNA replication. Describe the action of he…

Summer (May/Jun) 2023· 1

Enzymes that catalyse the removal of $ CH_{3} $ groups from cytosine bases in DNA are called TET enzymes. The rate of transcription increases when $ CH_{3} $ groups are removed from DNA. During embryo development, TET enzymes remove $ CH_{3} $ from a large number of genes. This T…

Winter (Oct/Nov) 2021· 1

Fig. 21 shows a molecule of ADP. Fig. 21 (a) (i) On Fig. 21, draw a circle around the part of the ADP molecule that is a purine. [1] (ii) State two differences between a molecule of ADP and a DNA nucleotide that contains adenine. 1 ..... [2] (iii) ADP binds with an inorganic phos…

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