1. They include all single celled eukaryotes.
2. They contain membrane bound cell organelles.
3. They possess well defined nucleus.
4. They have a cellular level of body organization.
5. They reproduce sexually and asexually.
6. Their mode of nutrition is autotrophic and heterotrophic.
7. They move across the environment using
8. Flagella, cilia, pseudopodia, or propulsion by contraction of the body and mucilage are the most significant forms of locomotory organelles present in them.
Fallowing are the members of the kingdom Protista
1. Chrysophytes(Planktons)
a) Includes diatoms and golden algae(desmids).
b) Found in fresh water as well as marine environments.
c) Microscopic; float passively in water currents.
d) Mostly photosynthetic.
e) cell wall forms two thin overlapping shells.
f) Walls embedded with silica, and thus, indestructible.
g)Fossilized remains of diatoms are referred to as 'diatomaceous earth'.
h)They are the chief producer of the ocean.
2. Dinoflagellates
a) Mostly marine and photosynthetic.
b) Appear yellow, green, brown, blue or red, depending on pigments present in their cells.
c) Cell wall has stiff cellulosic plates on the outer surface.
d) Most of these have two flagella-one lies longitudinally and the other transversely, in furrow between the wall plates.
e) Red dinoflagellates rapidly multiply and make the sea appear red(red tides).
f) Toxins released by these organisms may kill other marine animals.
3. Euglenoids
a) Majority are fresh-water organisms.
b) Found in stagnant water.
c) Have protein rich layer called pellicle, instead of cell wall, while makes their body flexible.
d) In the presence of sunlight, they behave like autotrophs; in the absence of sunlight, they have behave like heterotrophs, predating on smaller organisms.
e) Pigments are similar to those present in higher plants.
4. Slime Moulds
a) Saprophytic protists.
b) Move along decaying twigs and leaves.
c) Under suitable conditions, they form an aggregation called plasmodium, which grows and spreads.
d) Under unfavorable conditions, plasmodia differentiate to form fruiting bodies bearing spores at their tips.
e) Spores possess extremely resistant true walls, which make them capable for surviving for a long time under adverse conditions.
f) Spores disperse by air currents.
5. Protozoans
a) All are heterotrophs.
b) Live as predators or parasites.
c) Believed to be the primitive relatives of animals.
i) Amoeboid Protozoans
a) Live in fresh water, sea water or in moist soil.
b) Move and capture their prey by putting out pseudopodia(false foot); Example: Amoeba.
c) Marine forms have silica shells on their surface.
d) Some of them, such as Entamoeba, are parasites.
ii) Flagellated Protozoans
a) Either free-living or parasitic.
b) Bear flagella.
c) The parasitic forms cause diseases such as sleeping sickness; Example: Trypanosoma
iii) Ciliated Protozoans
a) Aquatic and actively moving.
b) Show presence of thousands of cilia.
c) Have a cavity(gullet) which opens on the outside.
d) Movement of cilia causes food-laden water to enter the gullet. Example: Paramecium
iv) Sporozoans
a) Include diverse organisms with spore like infectious stage in their life cycle. Example: Plasmodium, which causes Malaria.