Protozoa are unicellular eukaryotic microorganisms that are nonphotosynthetic and motile. They exist in a wide variety of environments and can be either free-living or parasitic.

"Animal-Like" Protozoans

Algae are autotrophic protists that can be unicellular or multicellular. They  are responsible for about 70% of the oxygen production in aquatic environments.

"Plant-Like" Algae

Lichens are nonpathogenic microorganism that is a combination of green algae and fungus. They can be found commonly slowly growing on rocks or plants.

Lichens

Protists have been historically informally grouped into three categories: 
- "Animal-Like" Protozoans
- "Plant-Like"  Algae
- "Fungus-Like" Protists

Georgetown University

University of Michigan - Ann Arbor

Types of Parasites

A kingdom made up of single-celled eukaryotes that consume organic matter. Members of this kingdom are not believed to all share a common ancestor, but instead share ancestors with members of the Fungi, Animalia and Chromista kingdoms.

Protozoa (Kingdom)

https://openstax.org/details/books/microbiology/

Microbiology covers the scope and sequence requirements for a single-semester microbiology course for non-majors. The book presents the core concepts of microbiology with a focus on applications for careers in allied health. The pedagogical features of the text make the material interesting and accessible while maintaining the career-application focus and scientific rigor inherent in the subject matter. Microbiology’s art program enhances students’ understanding of concepts through clear and effective illustrations, diagrams, and photographs.

Microbiology is produced through a collaborative publishing agreement between OpenStax and the American Society for Microbiology Press. The book aligns with the curriculum guidelines of the American Society for Microbiology.

OpenStax Microbiology Textbook

Multicellular organisms that can be parasitic or free living, unable to multiply while within humans (in adult form).

Helminths

Organisms that attach or burrow in to the skin for weeks to months long duration.

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