Plantlike Protists

1. Plantlike Protists • Commonly called Algae • One characteristic they all share is they are autotrophs (make their own food) • Live on trees, in soil, in fresh and salt water

2. The Diversity of Algae • Some are unicellular and live alone. Others are unicellular and live in colonies. When unicellular organisms live in a colony, they may become specialized to perform certain functions. • Others are multicellular. • Come in a wide variety of colors-depends on the pigments-chemicals that produce color.

3. Euglenoids • Green, unicellular organism found in freshwater • Unique characteristic-autotrophic when sun is out, heterotrophic when sunlight is not available. • Has a flagellum to move • Has light-sensitive pigments in eyespot Eyespot Euglena

4. Dinoflagellates • Unicellular algae covered with stiff plates • Vary in color from red to green and other colors • 2 flagella that are held in grooves between the plates • Many glow in the dark

5. Diatoms • Unicellular algae with glasslike cell walls • Move by oozing chemicals out of cell wall • They are an important food source for heterotrophs that live in the water • When they die, their cell walls collect on the bottoms of oceans and lakes. Over time, they form diatomaceous earth-used in filters of pool filters, for polishing things, and even toothpaste!

6. Green Algae • All contain green pigments • Most are unicellular, some form colonies, others are multicellular • Most live in either freshwater or saltwater, some are found on trees or moist soil. Ulva-sea lettuce Volvox releasing daughter colonies

7. Red and Brown Algae • Almost all are multicellular and found in oceans • Brown-have many plant-like structures such as a blade-like a leaf and holdfast-like roots • Brown algae have bladders-air filled sacs that help the algae to float upright in the water Brown Algae Red Algae

8. Why are these all Autotrophs??! • Because they all have pigment that help absorb sunlight. This sunlight is used to produce food by photosynthesis. • Example-Euglena has chlorophyll contained inside an organelle called a chloroplast.

9. Funguslike Protists • Like fungus, funguslike protists are heterotrophs, have cell walls and use spores to reproduce. • Unlike fungus, all funguslike protists can move at some point in their life • There are three types of funguslike protists: • Water molds • Downy mildews • Slime molds A water mold

10. Water Molds and Downy Mildews • Live in wet or moist places • Attack animals and crops • Water mold caused the Irish Potato Famine of 1845-1846 which resulted in over a million Irish people dying • Grow as tiny threads that look like a fuzzy covering Water Mold Spots of Downy Mildew on Spinach Leaf

11. Slug on Scrambled Egg Slime Mold Slime Molds • Live in moist soil and on decaying plants and trees • Often they are beautifully colored • Feed on bacteria and other microorganisms • When their food source runs low, they grow stalks that produce spores Spore Stalks Pink Slime Mold on Tree Bark

12. Protist Reproduction • Animal-like • Can reproduce sexually through Conjugation- when two join together and exchange genetic material • Can also reproduce asexually through Binary Fission- when an organism splits into two new organisms • Funguslike and Plantlike-most use spores to reproduce Conjunction in Paramecium Amoeba going through Binary Fission It’s splitting here!

13. Unique Structures • Contractile Vacuole- a structure that collects extra water and expels it from the cell. Almost all water living protists have them. If they did not have this, extra water may build up and the protist would pop! The Contractile Vacuole of a Paramecium