Protists are a diverse group of eukaryotic organisms that are not plants, animals, or fungi. They include algae, protozoans, and fungus-like protists. Protists can be unicellular or multicellular, autotrophic or heterotrophic, and live in water or moist environments. They reproduce asexually through cell division, sexually, or both. Protists show diversity in locomotion, metabolism, and structure.
2. Protists
• Protists are a very large, diverse group of
organisms, including the plant-like
protists (algae), fungi-like protists, and
the animal-like protists (protozoans).
• Animal-like Protists – also called
protozoa (means “first animal”) –
heterotrophs
Plant-like Protists – also called algae –
autotrophs
Fungus-like Protists – heterotrophs,
decomposers, external digestion
3. Definition
Protists are eukaryotic organisms that aren’t
plants, animals or fungi, which mainly live in
water.
Differences between plant-like and
animal-like protists
Plant-like Animal-like
can photosynthesise Do not
maybe unicellular or
*multicellular
unicellular
Feed on the sun Must feed on other living
organisms
*The multicellular types have no real roots, stems, or
leaves, just a simple body called a thallus
4. Characteristics of Protists
• mostly unicellular, some are multicellular
(algae)
• can be heterotrophic or autotrophic
• most live in water (though some live in
moist soil or even the human body)
• ALL are eukaryotic (have a nucleus)
• No tissue
6. Locomotion
• Cilia - Microscopic hair like
projections extending from the surface
of a cell or unicellular organism.
Capable of rhythmical motion, they
act in unison to bring about the
movement of the cell or of the
surrounding medium
Paramecium
7. • Flagella - A long, threadlike
appendage, especially a whip like
extension of certain cells or
unicellular organisms, found
singly or in pairs.
Euglena
Locomotion
8. • Pseudopodia - A temporary
projection of the cytoplasm of certain
cells, such as phagocytes, or of certain
unicellular organisms, especially
amoebas.
Amoeba
Locomotion
9. Metabolism
• There are two major groups;
Phototrophic Organotrophic
Make their own food; Does not make their
generally from the sun own food; eat food to
get energy
Kelp
Euglena
Dinoflagellate
plasmodium
Amoeba
11. Diversity
•
Paramecium –
cilia around the
outside
Volvox-
Large colony of
cells with a smaller
colony inside it
kelp
Diatoms – converting
silicon into glass at low
temperature