Transcript think!
Protists What is a Protist? The Protist Kingdom is also known as the “Junk Drawer Kingdom”. THINK! What does this nickname imply about the kingdom? The organisms in this kingdom are so different from each other However, all protists do share 2 characteristics They all have a nucleus They all live in moist surroundings Protist Groupings Because protists are such a diverse group, scientists group them into 3 different categories: THINK! – What characteristics do you think all animal-like protists share? All are heterotrophs and can move from one place to another THINK! – What characteristic do you think all plant-like protists share? Animal-like Protists Plant-like Protists Fungus-like Protists All are autotrophs THINK! – What characteristics do you think all fungus-like protists share? All are heterotrophs, have cell walls, and reproduce by spores Animal-like Protists Amoebas Cell Structure: These are unicellular organisms. Movement: They move with a pseudopod, meaning “false foot.” This is when the cell membrane fills with cytoplasm and pushes forward. They are known as shape shifters as they constantly change their shape by cytoplasmic streaming. Nutrition: They eat bacteria and other small protists using pseudopods to surround, or engulf, the food into a new food vacuole. Excess water is controlled and expelled from an amoeba through a contractile vacuole. • THINK! - Are they heterotrophic or autotrophic? Reproduction: Amoebas reproduce by binary fission. Take a Look at an Amoeba’s Structure! United Streaming Clip on Amoebas! Monsters Inside Me – Brain Eating Amoeba http://animal.discovery.com/videos/monsters-inside-me-the-braineating-amoeba.html Animal-like Protists Paramecium Cell Structure: These are unicellular organisms that have an outer pellicle. Movement: They move with tiny hairlike projections called cilia that cover the entire cell. Think of cilia as “tiny oars” that help to propel the cell forward. Nutrition: Cilia sweep food such as bacteria and other small protists into the cell. Food is stored and digested in food vacuoles. • THINK! – Are paramecia heterotrophic or autotrophic? Reproduction: Paramecia usually reproduce by binary fission but occasionally use conjugation to mix up the genes and increase genetic diversity. Let’s Take a look at a Paramecium! United Streaming Clip on Paramecium! Paramecium Eating Pigmented Yeast http://www.youtube.com/watch?v=l9ymaSzcsdY&feature=related Paramecium in HD http://www.youtube.com/watch?v=a4aZE5FQ284&feature=fvwrel Plant-like Protists Euglenoids Cell Structure: These are unicellular organisms. Movement: They move by using a flagellum. Nutrition: They contain chloroplasts which capture sunlight and turn it into food. However, sometimes when there is no light, they must seek out their food. An eyespot senses light. • THINK! - Are they heterotrophic or autotrophic? Reproduction: Euglenas reproduce by binary fission Let’s look at the Structure of A Euglena United Streaming Clip on Euglena! Euglena Movement - http://www.youtube.com/watch?v=fI7nEWUjk3A Euglena Under Microscope http://www.youtube.com/watch?feature=endscreen&v=4MlR3dKfXmc&NR= 1 Plant-like Protists Diatoms Cell Structure: These are unicellular with beautifull glass-like cell walls. Their shells are used in toothpaste, silver polish, pool filters etc. Movement: They move by oozing chemicals out of their cell walls and then gliding gracefully over the slime on the surface of fresh or salty water. Nutrition: They make their own food by capturing sunlight. • THINK! - Are they heterotrophic or autotrophic? Reproduction: Diatoms reproduce by binary fission Let’s take a look at Diatoms! United Streaming Clip on Diatoms! Plant-like protists Algae (Green, Red, and Brown) Cell Structure: Most green algae is unicellular. However, some green algae such as seaweed are multicellular. Red and brown algae are multicellular. Movement: Most algae are anchored to rocks or are floating in fresh or salty water. Nutrition: They make their own food by capturing sunlight. Green algae have a green pigment, red algae have a red pigment, and brown algae have a brown pigment. • THINK! - Are they heterotrophic or autotrophic? Reproduction: Most reproduce sexually. Let’s take a look at Simple Green Algae! Refer to the diagrams on page 88! United Streaming Clip on Simple, Unicellular Green Algae! Let’s take a look at Simple Green Algae! Refer to the diagrams in textbook! Video Clip -Importance of Algae in the Environment Fungus-like Protists Water Molds Cell Structure: Water molds grow as tiny threads that look like fuzzy coverings. Movement: They are able to move at some point in their life. Nutrition: Many feed off of crops such as potatoes, cabbages, corn, and grapes. Water molds led to the great Irish potato famine in 1845 that lead to over 1 million deaths of Irish people. • THINK! - Are they heterotrophic or autotrophic? Reproduction: Most reproduce by spores. Spores are tiny cells that have the potential to develop into an entirely new organism. Fungus-like Protists Slime-Molds Cell Structure: Slime molds are multicellular mass when they are clumped together as seen above. They are beautifully colored with many being a bright yellow. Movement: They move in an amoeba-like way using pseudopods and oozing along the surfaces. Nutrition: They feed on bacteria and decaying material. • THINK! - Are they heterotrophic or autotrophic? Reproduction: Most reproduce by spores. BEAUTY AND THE BLOB http://www.nytimes.com/slideshow/2011/10/04/science/20111004SLIME.html Movies of Slime Mold (Princeton Univ) http://www.youtube.com/watch?v=bkVhLJLG7ug