HSC Biology — Module 7
Pathogens — Flashcards & Quiz
Understanding pathogens is the foundation of HSC Biology Module 7: Infectious Disease. You need to recognise the five main categories — bacteria, viruses, fungi, protists and prions — and give a named example with its mode of transmission for each. Examiners often test the distinction between pathogens and parasites, and the unique challenges prions pose to traditional disease models. Linking each pathogen type to a named disease with a clear transmission route (for example, Mycobacterium tuberculosis for bacteria, influenza virus for viruses, Plasmodium for protists) lifts your answers from generic to exam-ready.
Sample Flashcards
Q1: Name the five main types of pathogens and give an example of each.
1) Bacteria (e.g. Mycobacterium tuberculosis — TB). 2) Viruses (e.g. Influenza virus). 3) Fungi (e.g. Tinea — athlete's foot). 4) Protists (e.g. Plasmodium — malaria). 5) Prions (e.g. CJD — Creutzfeldt-Jakob disease). Parasitic worms (helminths) are also studied.
Q2: What is the difference between a pathogen and a parasite?
A pathogen is any organism or agent that causes disease. A parasite is an organism that lives on or in a host and benefits at the host's expense. Not all parasites are pathogens (some cause minimal harm), and not all pathogens are parasites (e.g. prions).
Q3: How do viruses differ from bacteria?
Viruses: non-cellular, no organelles, contain DNA OR RNA (not both), cannot reproduce independently (need host cell machinery), not killed by antibiotics. Bacteria: unicellular prokaryotes, have ribosomes and cell wall, reproduce by binary fission, some killed by antibiotics.
Q4: What are prions and why are they unusual?
Prions are misfolded proteins (no DNA or RNA) that cause other normal proteins to misfold. They are not living organisms and cannot be destroyed by normal sterilisation, UV, or antibiotics. They cause fatal neurodegenerative diseases.
Sample Quiz Questions
Q1: Bacteria are smaller than viruses.
Answer: FALSE
Viruses are much SMALLER than bacteria. Bacteria are typically 1-10 micrometres; viruses are typically 20-300 nanometres.
Q2: Antibiotics are effective against viral infections.
Answer: FALSE
Antibiotics target bacterial structures (cell walls, ribosomes) and are NOT effective against viruses. Antiviral medications are used for viral infections.
Q3: Prions contain DNA and can reproduce independently.
Answer: FALSE
Prions are misfolded proteins — they contain NO DNA or RNA and cannot reproduce. They cause disease by inducing normal proteins to misfold.
Related Concepts
Last updated: March 2026 · 4 flashcards · 3 quiz questions