Kingdom Protista

Marine forms

have silica shells on their surface.

protozoans

All are heterotrophs and live as predators or parasites.

Protists

reproduce asexually and sexually by a process involving cell fusion and zygote formation.

diverse organisms

It includes that have an infectious spore- like stage in their life cycle.

eukaryotes

Being , the protistan cell body contains a well defined nucleus and other membrane- bound organelles.

primitive relatives of animals

They are believed to be .

cell wall

Instead of a(n) , they have a protein rich layer called pellicle which makes their body flexible.

pigments of euglenoids

The are identical to those present in higher plants.

cell walls

The form two thin overlapping shells, which fit together as in a soap box.

cell wall

The has stiff cellulose plates on the outer surface.

Characteristics of members of Kingdom Protista

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Examples

Diatoms and Golden Algae (Desmids)

Most of them have two flagella

one lies longitudinally and the other transversely in a furrow between the wall plates

Example

Gonyaulax (red dinoflagellate)