Protozoan Diversity Part 2

Contributor: Felicia Sabur. Lesson ID: 12011

How can such tiny creatures cause so much agony? When you are sick, do you actually have a bug? Explore the world of these nasty parasites, and how they reproduce and move about!


Life Science

learning style
personality style
Grade Level
High School (9-12)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

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  • What do ferns, mushrooms, and sporozoans have in common?
  • What is a sporozoan, and would you want one on your pizza?

Protozoans are animal-like protists and unicellular heterotrophs.

They are a very diverse group; some are classified by how they move, while others are grouped because they are parasites. In this lesson, learn about the last of the four main groups of protozoans, the sporozoans.

Protists that belong to the phylum Sporozoa are called sporozoans because they produce spores. Other organisms that produce spores that you may be more familiar with are mushrooms and ferns.

Sporozoans are parasites and are usually found in the parts of a host with a readily-available food supply, like the animal’s bloodstream or intestines.

They have a very complex life cycle and use spores to reproduce. A spore is a reproductive cell that can grow into a new organism without fertilization. The Sporozoa reproduction cycle has both asexual and sexual phases.

For a detailed description, check out Sporozoa.

Toxoplasma gondii are members of the Sporozoa phylum, and they cause a disease known as toxoplasmosis. This parasite can be found worldwide, and many infected people do not have symptoms at all because their immune system protects them from the parasite.

However, a toxoplasma gondii infection can be dangerous for pregnant women and individuals with compromised immune systems. The parasite is present in cat feces and can be transmitted through contact with infected feces.

graphic showing the life cycle from a cat to a pregnant woman

Plasmodium are also members of the Sporozoa phylum, and they cause malaria in birds, mammals, and humans.

Malaria is a serious disease that occurs in regions of the world with tropical climates. It is spread by females of only certain species of the Anopheles genus of mosquitos. Below is a microscope picture of Plasmodium malariae that has infected red blood cells.

  • Which type of movement do you think they use?

purple cells under a microscope

Sporozoans reproduce by producing spores, and they are parasitic. Some sporozoans, like plasmodium, can be very harmful to humans.

In the Got It? section, complete a quiz on what you have just learned.

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