The Protists Kingdom

1. The Protists Kingdom

2. What Are Protists? • A group of one-celled organisms with well defined nuclei • All protists live in moist surroundings • Many protists possess both plant-like and animal-like features • Animal like protists are called PROTOZOAN

3. We will take a close look at four protists that are similar in some respects and are also very different in others. Similarities: All have cytoplasm surrounded by a protective covering All have a well-defined nucleus All reproduce asexually by cell division (binary fission) All have vacuoles All move about their environment

4. Amoeba • The amoeba is a tiny, one-celled organism • The name amoeba comes from the Greek word amoibe, which means change • They are legendary as the ultimate shape shifters • Amoeba are quite hard to find

5. Amoeba • An amoeba consists of a single blobby cell surrounded by a porous cell membrane. • The amoeba "breathes" using this membrane • Amoebas move by changing the shape of their body, forming pseudopods (temporary foot-like structures). • The word pseudopod means "false foot."

6. The pseudopodia movement that enables the amoeba to capture prey. • Usually the pseudopods form a kind of dome that makes escaping impossible. • They must have some sort of chemical detection since they notice a prey without having to touch it. These two images of Amoeba proteus shows how a fast moving ciliate is surrounded by quick developing pseudopodia.

7. Paramecium • The paramecium is larger than the amoeba • Shaped like a slipper, its name comes from the Greek word for “oval” • It is common in ponds throughout the world • Paramecium is a good example of cell • complexity.

8. The paramecium has two nuclei, a big and small one • The big one operates as the director of the cell's activities, rather like a little brain • The smaller one is used for reproduction

9. It is covered with tiny hairs called cilia that help it move • The paramecium is able to move in all directions with these cilia • The cilia also propels the food into a tiny mouth called the oral groove

10. Euglena • The euglena is unique because it is sort of like a plant and also like an animal • It is pear shaped • It has a whippy tail called a flagellum that allows it to move through the water

11. The euglena is able to make its own food like a plant when it is in the sunlight • When it is in darkness, however, it can find food like an animal • It takes in tiny plants and animals much like the amoeba and paramecium.

12. Interesting Fact • When it is too hot or cold for a euglena, it forms a protective casing called a cyst around its body that protects it until conditions outside the cyst become better.

13. Volvox • Volvox is a green algae • It exists as a grand spherical colony • The bright green spheres within are "daughter colonies" The individual algae are connected by thin strands of cytoplasm.

14. The volvox resembles a little planet • In the northern region the eyespots are more developed • This differentiation of cells make Volvox quite unique Each little alga within the colony bears two flagella, whip-like hairs. The individual alga also have small red eye spots.

15. One of the 7 Wonders of the Micro World Sometimes we can find inhabitants within the colony. There is a small rotifer, called Proales parasita that lives inside Volvox and feeds on the cells.