Protists

Characteristics live in water eukaryotic most are unicellular, some are multicellular (algae) some are autotrophic (can make own food); some are heterotrophic (cannot make own food)

Characteristics (cont.) all can reproduce asexually (by mitosis or binary fission); some are capable of sexual reproduction (by conjugation)

Characteristics (cont.) -some have cells with contractile vacuoles that help maintain homeostasis (can hold and expel fluid)

Can be … 1.animal-like (protozoa) – absorb or gather/capture food *flagellates – move by flagella examples: ones that live in termite’s intestine, ones that cause African sleeping sickness

More animal-like protists … sarcodines – uses pseudopods to move and capture prey example: amoeba

More animal-like protists … ciliates – move/eat by cilia, has oral groove and anal pore example: paramecium allery/pondscum/protozoa/parameci um/index.html

Still more animal-like protists … sporozoans – parasitic, reproduces by spores example: Plasmodium (malaria)

2. plant-like (algae) – contain chlorophyll and are photosynthetic *Euglena – can make and consume food tozoa/euglena/rostrifera/index.html Can be …

More plant-like protists … diatoms – various shapes, cell walls of silicon are used in toothpaste and scouring products

More plant-like protists … *dinoflagellates – have flagella; one example causes red tide

Still more plant-like protists … *multicellular algae – green, brown, red

3. fungus-like – cell walls, absorb nutrients, reproduce by spores *slime molds Can be …

More fungus-like protists … *water molds – ex. Phytophthora infestans – cause of Irish potato famine (1845 – 1852)