Kingdom Kingdom ProtoctistaProtoctista

Kingdom ProtoctistaKingdom Protoctista

• Includes Protozoa and Algae• Some are microscopic, but some can be observed by

the unaided eye• Some are unicellular organisms, but some are

multicellular (i.e. made up of many cells) with a simple body structure

• They DO have a nucleus and organelles• They are very abundant, free living in water or damp

environment, or as parasites in other organisms

ProtozoaProtozoa(Singular: Protozoan)(Singular: Protozoan)

ProtozoaProtozoa

• “Animal-like” protoctist

• Found in wide range of habitats such as fresh water, sea water, soil and inside bodies of plants and animals, where moisture is available

• Usually unicellular

• Larger in size than bacteria

• Do not have cell wall

ProtozoaProtozoa

• Lack chlorophyll – why is this significant?

Cannot carry out photosynthesis!

• Feed on smaller organisms and small food particles

• Motile – some of them possess flagella (singular: flagellum) or cilia (singular: cilium)

Flagella

Cilia

ProtozoaProtozoa

Examples of Protozoa:• Amoeba

• Paramecium

AmoebaAmoeba

AmoebaAmoeba

Acanthamoeba are free-living amoeba commonly found in tap water. It can cause damages to the cornea. Always use sterile solution to clean contact lenses!

ParameciumParamecium

AlgaeAlgae(Singular: Alga)(Singular: Alga)

AlgaeAlgae

• “Plant-like” protoctist

• Found in sea water and fresh water

• Can be either unicellular or simple multicellular

• Each cell is surrounded by a cell wall

• Possess chloroplasts which contain chlorophyll and other photosynthetic pigments for making their own food by photosynthesis

Some different types of algae

AlgaeAlgae

Examples of Algae:• Spirogyra

• Seaweeds

SpirogyraSpirogyra

SeaweedsSeaweeds

EuglenaEuglena

Euglena is a protoctist that shows a mixture of features of protozoa and algae. It contains chlorophyll and carries out photosynthesis, but it also feeds on smaller organisms. It has a flagellum and is able to move about in water.

ChallengeChallenge

What is the main difference between

prokaryotes and protoctists?

The presence of a distinct nucleus in protoctists!!!