Protists Protists are a range of organisms that have many different features. This makes them really hard to classify.

Protists While protists range significantly they do share common characteristics: Most are unicellular May be autotrophic or heterotrophic Cells are eukaryotic and have membrane bound nucleus, vacuoles, and mitochondria Cells reproduce asexually by binary fission (some through sexual reproduction) Cells thrive in moist environments (such as fresh water, salt water, animal fluids)

Protists Examples Top left: Volvox Bottom left: Amoeba Top right: Paramecium Middle: Chlamydomonas Bottom right: Trypanosoma (african sleeping sickness)

Organizing Protists 3 Categories: Animal-like Protists Fungus-like Protists Plant-like Protists

1. Animal-like Protists (a.k.a. Protozoa) Examples amoeba, paramecium, malaria 1. Animal-like Protists (a.k.a. Protozoa) Are all heterotrophic Capable of moving in order to feed Uses pseudopod to grab food and move Various methods of locomotion Cilia Flagella Pseudopod * Parasitic

E.g. 1 Amoeba (Phylum: Cercozoa) Surface is a cell membrane (flexible) Use temporary extensions known as pseudopodia (false feet) to feed and move Live in moist environments Intestinal parasite amoebas can be contracted through contaminated water

E.g. 2 Paramecium (Phylum: Ciliophora) Contain many cilia (for feeding and locomotion) Food in brought in through the oral groove

E.g. 3 Trypanosoma (Phylum: Zoomastigina) This phylum has one or more flagella Causes the sleeping sickness

E.g. 4 Plasmodium (Phylum: Sporozoa) Plasmodium is the bacteria that causes malaria in humans Infects both humans and mosquitos When a human is infected with malaria, a mosquito that bites that human will also carry malaria. When the malaria carrying mosquito bites another human, the human is now infected.

2. Fungus-like Protists Known as slime moulds or water moulds They like cool, shady, moist places Are heterotrophic decomposers Have cell walls Can move at one point in their life

3. Plant-like Protists They contain chlorophyll (used in photosynthesis) They are autotrophic when light is present (in darkness they are heterotrophic). E.g. Euglena Contains an eyespot (for detecting light) and a flagellum (for propelling through water) Has a pellicle instead of a cell wall (is more flexible for movement)

3. Plant-like Protists Other examples include: Dinoflagellate Green Algae Red Algae Brown Algae

3. Plant-like Protists Why are algae important? They are primary producers (they make sugar and oxygen essential for aquatic organisms) Without them all fish would die Algae also produce oil and are used as fertilizer Algae can also cause harm: Too much algae can block sunlight from water, and “sufficate” the lake.

Homework Read pages 72-78. #19-21, 23 (p.76) #2-4, 7-8, 10, 12 (p.78)