Unit 1: Unity and Diversity
Topic 1.5: Viruses (HL) Questions
Practice 20 exam-style questions for IB Biology Topic 1.5. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
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State the type of nucleic acid that reverse transcriptase uses as its template, and the type of nucleic acid it produces.
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Reverse transcriptase catalyses the production of which molecule, and from which template?
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State what is meant by the term lysis in the context of the lytic cycle.
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State the term for the phage DNA once it has integrated into the host bacterium's chromosome in the lysogenic cycle.
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Which feature shows that a virus is non-cellular?
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Which two parts are found in EVERY virus?
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In the lysogenic cycle, the integrated phage DNA sitting dormant inside the host chromosome is called a:
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State the term used to describe an evolutionary origin involving several separate, independent origins rather than one common ancestor.
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State the types of nucleic acid that can make up a viral genome.
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The protein capsid of a virus is built from many repeating protein sub-units.
What are these sub-units called?
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Which feature is unique to a temperate phage but not to a purely lytic phage?
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What happens to the host cell at the lysis stage of the lytic cycle?
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A virus has a coat shaped like a many-sided 'ball' enclosing its genome.
Which capsid shape is this?
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Why do RNA viruses generally evolve faster than DNA viruses?
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How does a virulent phage produce many copies of its genome and proteins during the replication stage?
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Which hypothesis proposes that viruses began as host genes or mobile genetic elements that escaped the cell and gained a protein capsid?
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Which statement about the attachment stage is correct?
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The evolutionary origin of viruses is described as 'polyphyletic'.
What does this mean?
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How is a prophage copied each time its host bacterium divides?
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Which pair of outcomes best describes the net effect of one complete lytic cycle?
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