Malaria causes recurrent episodes of fever and can be fatal.

The idea

Malaria is a disease caused by a protist pathogen, Plasmodium, which is transmitted between humans by mosquito vectors. The protist enters the blood when an infected female mosquito takes a blood meal, then travels to the liver and later invades red blood cells, where it multiplies in cycles. When these cells burst, toxins are released that trigger recurrent episodes of fever, often with chills, sweating and headache. Because the cycle repeats, the fever comes back again and again rather than staying constant. In severe cases, malaria can damage organs such as the brain and kidneys, and it can be fatal, especially in young children, pregnant women and people with weakened immunity. Understanding this helps explain why controlling mosquito numbers and avoiding bites are so important.

What earns the marks

• Malaria is caused by a protist pathogen, specifically Plasmodium species.
• The pathogen is transmitted to humans by the bite of an infected mosquito, which acts as a vector.
• The protist multiplies inside red blood cells, causing them to burst and release toxins.
• The release of toxins produces recurrent episodes of fever rather than a single continuous fever.
• Malaria can be fatal, particularly in vulnerable groups such as young children and pregnant women.
• The recurring nature of the fever is linked to the repeated cycle of infection and bursting of red blood cells.

Common mistakes and how to put them right

• Saying that malaria is caused by a virus or bacterium.

  Put it right: It is caused by a protist, Plasmodium.

• Saying that mosquitoes cause malaria directly.

  Put it right: Mosquitoes are vectors that transmit the protist pathogen.

• Describing the fever as constant rather than recurrent.

  Put it right: Fever episodes repeat as red blood cells burst in cycles.

Exam tips

• Name the pathogen group (protist) and the genus Plasmodium to show precise knowledge.
• Link the recurrent fever to the life cycle of the pathogen inside red blood cells, not just to the bite.
• Use the word vector correctly: the mosquito transmits the pathogen but is not the pathogen itself.