Kingdom Protista

If you look at a drop of pond water under a microscope, all the "little creatures" you see swimming around are protists.

Prokaryotes are organisms that are not as organized and do not have a nucleus. All protists have a nucleus and are therefore eukaryotic. Protists are either plant-like, animal-like or fungus-like.

Protists: Kingdom Protista Protists: Kingdom Protista. Includes protozoans, most algae, and some fungi (slime mold) Plant-like protists are autotrophs – they contain chloroplasts and make their own food. Animal-like and fungus-like protists and are heterotrophs.

Protozoans are animal-like protists (heterotrophs) grouped according to how they move. The word protozoa means "little animal." They are so named because many species behave like tiny animals—specifically, they hunt and gather other microbes as food.

Protozoa are classified into three general groups based on how they move. Cilia – tiny hairs Flagella – whip Pseudopod – false feet Non-motile – cannot move at all

Amoebae ooze along by means of pseudopodia (false feet) engulfing food as they go. Amoebae live in water or moist places. They have a cell membrane but no cell wall.

Amoeba

Flagellates are generally the smallest of the protozoa and have one or several long, whip-like projections called flagella poking out of their cells. Flagellates use their flagella to move.

Giardia lamblia – a flagellate Causes beaver fever Fatigue, diarrhea, cramps, weight loss Does not harm beavers but can harm humans

Flagellates

Ciliates are generally the largest protozoa. They are covered with hair-like projections called cilia and they eat the other two types of protozoa as well as bacteria. Ciliates are found in every aquatic habitat.

Ciliates

Paramecium – a ciliate

Sporozoans are the last group. These are parasitic and nonmotile. This means they feed off of others and cannot move at all.

They produce much of Earth’s oxygen. Plant-like protists are algae. Algae are eukaryotic (organized and have a nucleus) autotrophs (make their own food). Photosynthetic algae are the most important primary producers of the world’s freshwater and marine ecosystems Many are microscopic Some are huge: kelp They produce much of Earth’s oxygen.

Diatoms Giant Kelp

One kind of algae, Euglenoids, are both plant-like and animal-like. Euglena are autotrophs since they make food from sunlight and Heterotrophs since they ingest food from surrounding water.

Euglenoids

Euglena Euglena can become so numerous it may turn the water of a pond bright green. Euglena can move by flexing their bodies and changing their body shape. This is called Euglenoid motion. Euglenids have the ability to lose their chloroplasts. If you kept Euglenids in the dark, they start feeding on organic matter and may lose their pigment. There are many species without chloroplasts.

Another kind of algae are green and are called chlorophytes. Most green algae are found in fresh water habitats.

Volvox are a kind of chlorophyte Volvox are a kind of chlorophyte. They form large, spherical colonies in fresh water.