Protists are eukaryotic, primarily unicellular organisms that are not classified as plants, animals, fungi, or bacteria. They contain membrane-bound organelles and can be photoautotrophs like plants, saprotrophs like fungi, or heterotrophs like animals. Protists are classified based on their method of obtaining nutrition, and include protozoans, algae, and fungus-like protists. While some protists are harmful parasites or can cause harmful algal blooms, many are beneficial as they recycle nutrients, are a food source for other organisms, produce oxygen, and make contributions such as agar and food products.

1. By Mr Biswanath prusty

2. 1. Any organism not classified as a—plant, animal,
fungus, or bacteria (prokaryote).
2. Protists are eukaryotic having a distinct nucleus
and organelles.
3. Most protists are unicellular (one-celled) but
some are multicellular.

3. 4. This kingdom is connecting link between
kingdom monera and other three kingdom.
5. The cell possess all membrane bound cell
organelles like mitochondria, chloroplast,
endoplasmic reticulum, lysosome etc.
6. Organism are photoautotrophs like plants,
saprotrophs and decomposer like fungi and
heterotrophs and holozoic like animal.

4. • This kingdom Protista include following five
phylums.
phylum: protozoa(include unicellular and
holozoic organism)
Phylum: myxomycota (include saprotrophs and
decomposer)
phylum: Chrysophyta
phylum: donotlagellata
phylum: Euglenophyta (slime moulds)

5. Key point

7. 4. Protists are primarily classified according to
how they obtain nutrition:
a. Animal-like—heterotrophs
(eat other organisms)
b. Plant-like—autotrophs
They contain chloroplasts
and make their own food
(photosynthesis).
a. Fungus-like—
Decomposers/Heterotrophs
Didinium
Paramecium
eating
Green like plants!
Water mold

8. Animal-like Protists (Protozoans)
1. Method of Movement:
a. Cilia—hair-like projections used for movement and
feeding
b. Cytoplasmic streaming—pseudopod (false foot) extends
and cytoplasm streams into it.

9. 2. Paramecium:
Nucleus
Cilia
Cell Membrane
Contractile Vacuole
Collects and removes excess H2O
(Maintains homeostasis)
Oral Groove
Used to collect food

10. 3. Amoeba:
Nucleus
Contractile Vacuole
Pseudopod
(False foot)

11. 4. Importance of Animal-like
Protists:
a. Harmful
i. Disease-causing parasites spread
by insect bites
1. Malaria—Plasmodium spread
by mosquito
2. African Sleeping Sickness—
Trypmosoma
spread by Tsetse fly

12. b. Beneficial
i. Recycles nutrients by breaking down dead matter
ii. Food source—for other organisms
iii. Mutualism—both organisms benefit
Example: Trichonympha—makes it
possible for termites to eat
wood. Termites do not have the
enzymes to digest wood.

13. Plant-like Protists
1. Method of Movement:
a. Flagellum—whip-like structure used for movement
2. Euglena:
Nucleus
Contractile Vacuole
Chloroplasts
Flagella
Eyespot For photosynthesis
(light)

14. 3. Unicellular Algae:
a. Phytoplankton provides a source of nourishment for
other organisms
b. Protists recycle sewage and waste materials.

15. C. Algal blooms are harmful when overgrown—deplete water of
nutrients consequently killing fish.
Algal blooms called Red Tides cause illness, paralysis, and
death of fish and even humans.

16. 4. Multicellular Algae:
a. Examples---
i. Red Algae
ii. Green Algae
iii. Brown Algae

17. 5. Uses of Algae:
a. Algae is a good food source for life in
the oceans.
b. Algae produces much of Earth’s oxygen
through photosynthesis.
c. Algae is used to make sushi, ice cream,
salad dressing, plastics, paint, agar.

18. Fungus-like Protists:
1. Examples—
a. Slime molds
b. Water molds

19. 2. Importance of Fungus-like Protists:
a. Beneficial—
Recycles dead organic material. Results
in rich, topsoil providing nutrients for
plants.

20. b. Harmful—
P. Infestans (water mold) caused
Great Potato Famine in Ireland.
This lead to the mass starvation of
1 million Irish people.