Chapter 8.1b Protists Pgs. 215 - 220

Animal-like Protists One-celled animal-like protists are called protozoans. They are classified by how they move. All of these organisms eat other organisms.

Ciliates These protists have cilia – short, threadlike structures that can be used for movement. One ciliate is a Paramecium – they are large cells with 2 nuclei (macronucleus and micronucleus). They feed on bacteria

Flagellates Use a flagella. Most live in freshwater but a few are parasites.

Movement with Pseudopods Pseudopod means false foot – the single celled organism pushes out their cytoplasm to move. An amoeba is in this group. Watch the video to see how an amoeba moves. http://www.youtube.com/watch?v=pvOz4V699gk

Other Protozoans There is a group of protozoans that do not move, instead they are parasites in humans and other animals. Malaria is an example.

Importance of Protozoans They are a source of food for larger organisms. They also become sediment in the ocean. One type lives in termites and allows the termite to break down wood.

Disease in Humans An example is Giardia – causes diarrhea

Funguslike Protists Includes slime molds, water molds, and downy mildews. They all produce spores but can move from place to place with pseudopodia.

Slime Molds Slime molds are usually brightly colored. Most are found on decaying logs or dead leaves.

Water Molds and Downy Mildews They live in water or moist places. Digestion takes place outside their bodies. Water molds can be parasites of plants. They are fuzzy, white growths.

Importance of the Funguslike Protists They breakdown dead organisms. But they are also important because of diseases they cause in plants and animals. Water molds can attack fish. Downy mildew can attack plants – they caused a huge problem with potatoes in Ireland in the 1840s and caused a food shortage.