Year 9 Science · Unit 1 · Lesson 2

Types of Pathogens

Foundation Worksheet

Name

Date

Class

Learning Goals

Name the five main types of pathogen: bacteria, viruses, fungi, protozoa, and parasitic worms (helminths).
Identify an example disease and appropriate treatment for each pathogen type.
Explain why antibiotics work on bacteria but not on viruses.

Warm Up

Fill the gap

Choose the correct word from the word bank to complete each sentence. Two words will not be used.

bacteria virus fungi protozoa helminth antibiotic pathogen antigen symptom

Any microorganism or particle that causes disease is called a . The five main types are: , which are single-celled prokaryotes that reproduce by binary fission; , which are not cells and can only reproduce inside a host; , which include yeasts and moulds and are treated with antifungal medications; , which are single-celled eukaryotes such as Plasmodium (malaria); and a , which is a multicellular parasitic worm such as a tapeworm. Bacterial infections can be treated with an , but this treatment has no effect on viral infections.

Your Turn

Compare pathogens

Complete the table to compare four pathogen types. Use the lesson to fill in each blank cell. Note: viruses are not cells.

Feature	Bacteria	Virus	Fungi	Parasite
Cell type (prokaryote / eukaryote / not a cell)
Has genetic material (DNA / RNA / both / none)?
How does it reproduce?
Example disease
Treatment type

Show What You Know

1. List the following pathogen types in order from smallest to largest: virus, bacterium, protozoa, helminth (parasitic worm).

Recall 2 marks

2. Explain in one or two sentences why antibiotics can kill bacteria but have no effect on viruses. Refer to the structure of each type of pathogen in your answer.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?