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
http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/amoeba/index.html
More animal-like protists …
• ciliates – move/eat by cilia, has oral
groove and anal pore
example: paramecium
http://micro.magnet.fsu.edu/movieg
allery/pondscum/protozoa/parameci
um/index.html
Still more animal-like protists …
• sporozoans – parasitic, reproduces by
spores
example: Plasmodium (malaria)
Can be …
2. plant-like (algae) – contain chlorophyll
and are photosynthetic
* Euglena – can make and consume
food
http://micro.magnet.fsu.edu/moviegallery/pondscum/pro
tozoa/euglena/rostrifera/index.html
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
Can be …
3. fungus-like – cell walls, absorb nutrients,
reproduce by spores
* slime molds
More fungus-like protists …
* water molds – ex. Phytophthora infestans
– cause of Irish potato famine (1845 –
1852)