Kingdom Protista

Protista

A kingdom of diverse eukaryotic organisms, mostly unicellular, that are not fungi, plants, or animals.

Chrysophytes

A group of protists including diatoms and golden algae, characterized by silica cell walls and being major producers in aquatic environments.

Diatomaceous Earth

Accumulated deposits of silica cell walls of diatoms, used in polishing, filtration, and insulation.

Dinoflagellates

A group of marine, photosynthetic protists with stiff cellulose plates on their outer surface and two flagella, some causing red tides.

Red Tides

Rapid multiplication of certain red dinoflagellates (e.g., *Gonyaulax*) causing the sea to appear red and releasing toxins harmful to marine life.

Euglenoids

A group of freshwater protists lacking a cell wall, possessing a flexible pellicle, two flagella, and exhibiting mixotrophic nutrition.

Pellicle

A protein-rich, flexible layer found in Euglenoids that provides structural support instead of a cell wall.

Slime Moulds

Saprophytic protists that form a plasmodium under favourable conditions and resistant spores under unfavourable conditions.

Plasmodium

A large, multinucleate, naked protoplasmic mass formed by slime moulds under favourable conditions.

Protozoans

A diverse group of heterotrophic protists that are considered primitive relatives of animals, categorized by their mode of locomotion.

Pseudopodia

Temporary protoplasmic extensions used by amoeboid protozoans for movement and capturing food ('false feet').

Mixotrophic

A mode of nutrition where an organism can obtain nutrients by both photosynthesis (autotrophy) and consuming other organisms (heterotrophy), as seen in Euglenoids.