protists protists are a range of organisms that have many different features. this makes them really...
TRANSCRIPT
ProtistsProtists are a range of organisms that
have many different features. This makes them really hard to classify.
ProtistsWhile protists range significantly they do share common
characteristics:
1. Most are unicellular
2. May be autotrophic or heterotrophic
3. Cells are eukaryotic and have membrane bound nucleus, vacuoles, and mitochondria
4. Cells reproduce asexually by binary fission (some through sexual reproduction)
5. Cells thrive in moist environments (such as fresh water, salt water, animal fluids)
Protists Examples
Organizing Protists
3 Categories:
1. Animal-like Protists
2. Fungus-like Protists
3. Plant-like Protists
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
1. Cilia2. Flagella3. Pseudopod* Parasitic
Examples amoeba, paramecium,
malaria
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 ProtistsKnown 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 ProtistsWhy 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)