Unit 1: Unity and Diversity
Topic 1.2: Nucleic Acids Questions
Practice 20 exam-style questions for IB Biology Topic 1.2. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
1Identify1 mark
Which molecule acts as the long-term genetic material stored in the cells of an oak tree?
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In a DNA double helix, which components of the two strands are directly joined to each other by hydrogen bonds?
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Unlock Question3State1 mark
State the name of the monomer from which a DNA molecule is built.
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A short single strand of DNA has the base sequence T–A–C–G–G–A.
State the base sequence of the complementary strand that pairs with it.
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Unlock Question5Outline2 marks
Outline the feature of DNA that gives it the capacity to store a very large amount of information.
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Unlock Question6Distinguish2 marks
Distinguish between a gene and a genome.
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Outline the meaning of complementary base pairing in a molecule of DNA.
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What does whole genome sequencing of an organism involve?
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A short single strand of nucleic acid is found to contain the base uracil.
Which type of nucleic acid must this strand be, and why?
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The diagram shows a single nucleotide.
Which three components does every nucleotide contain?
[Diagram: bio-dna-nucleotide {"type":"DNA"}]
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Unlock Question11Identify1 mark
Which feature of a DNA molecule gives it the capacity to store a very large amount of genetic information?
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What molecules make up the backbone that runs along the outside of each DNA strand?
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2026
State the name of the protein around which DNA is wound in a eukaryotic nucleus.
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Watson and Crick published a model of DNA in 1953.
What overall structural feature did their model first reveal?
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In a plant or animal chromosome, what is the role of histone proteins?
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Which pair of base pairings correctly describes complementary base pairing in a DNA double helix?
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A pentose sugar is extracted from a nucleotide and shown to be deoxyribose.
From which nucleic acid did this nucleotide come?
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Which statement correctly describes the genome of an organism?
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2026
Calculate the percentage of guanine.
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