Fungal and Protist Diseases
Build confidence in Fungal and Protist Diseases for GCSE Biology with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Rose black spot (a fungus) and malaria (a protist spread by mosquitoes) are the examples to remember here.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
One fungal disease and one protist disease are required: rose black spot and malaria.
Rose black spot is a fungal disease causing purple or black spots on rose leaves. The leaves then turn yellow and drop early, so less photosynthesis occurs and growth is poor. It spreads in the environment by water and wind, and is treated with fungicides or by removing and destroying affected leaves.
Malaria is caused by a protist and spread by mosquitoes acting as vectors. It causes recurrent episodes of fever and can be fatal. Because the mosquito is the vector, control focuses on preventing the vector from breeding and on using mosquito nets to avoid being bitten.
Revision notes
Rose black spot
A fungal disease producing purple or black spots on the leaves of roses.
Affected leaves turn yellow and drop early, reducing photosynthesis and therefore growth. It spreads by water and wind. Treated with fungicides, or by removing and destroying affected leaves.
Malaria
Caused by a protist, with mosquitoes acting as the vector that carries it between hosts.
It causes recurrent episodes of fever and can be fatal. It remains a major cause of death in many parts of the world.
Vector control
The spread of malaria is controlled by preventing the mosquitoes from breeding — for example by draining standing water — and by using insecticide-treated mosquito nets to avoid bites.
Because the pathogen travels via a vector, removing the vector breaks the transmission cycle.
Key points
- Rose black spot is a fungal disease of roses.
- It causes black spots, then yellowing and leaf drop.
- Leaf loss reduces photosynthesis and growth.
- Malaria is caused by a protist.
- Mosquitoes are the vector for malaria.
- Malaria is controlled by preventing mosquito breeding and using nets.
Worked examples
Example 1
Explain how rose black spot reduces the growth of a rose plant. [3 marks]
Model answer
It causes black spots on the leaves, which then turn yellow and drop off early (1 mark). With fewer leaves the plant carries out less photosynthesis (1 mark), so less glucose is made for growth (1 mark).
Example 2
Explain what is meant by a vector, using malaria as an example. [2 marks]
Model answer
A vector is an organism that carries a pathogen from one host to another without getting the disease itself (1 mark). In malaria the mosquito is the vector, carrying the protist between people (1 mark).
Example 3
Give two ways the spread of malaria can be reduced. [2 marks]
Model answer
Preventing mosquitoes from breeding, for example by draining areas of standing water (1 mark), and using insecticide-treated mosquito nets to avoid being bitten (1 mark).
Common mistakes
Saying malaria is caused by a mosquito.
The mosquito is the vector; the pathogen is a protist.
Saying malaria is bacterial.
It is caused by a protist, which is one of the four pathogen types.
Not linking leaf loss to reduced growth.
The chain is fewer leaves, less photosynthesis, less glucose, poorer growth.
Suggesting antibiotics for a fungal disease.
Fungicides treat fungal diseases; antibiotics work on bacteria.
Exam tips
- Name the pathogen type precisely — protist for malaria, fungus for rose black spot.
- Define a vector as carrying the pathogen without getting the disease.
- Follow the full chain when explaining reduced plant growth.
- Give two control measures when the marks allow.
Key terms
- Protist
- A single-celled organism, one of the four pathogen types.
- Vector
- An organism carrying a pathogen between hosts.
- Fungicide
- A chemical used to treat fungal disease.
- Rose black spot
- A fungal disease causing black spots on rose leaves.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.