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A Handbook of Biology

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They have 2 flagella, a short and a long one.

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They are photosynthetic in the presence of sunlight. In the absence

of sunlight, they behave like heterotrophs by predating on smaller

organisms.

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The pigments are identical to those in higher plants.

E.g. Euglena (connecting link between plants and animals)

SLÏMË MØÜLDS (MÝXØMÝÇËTËS)

The

body

moves

along decaying twigs

and leaves engulfing

organic material

They are saprophytic

protists, without cell

wall.

1

2

Under suitable conditions, they form

an aggregation called plasmodium.

It may spread over several feet.

3

Under unfavourable conditions, plasmodium differentiates and forms

fruiting bodies bearing spores at their tips. Spores have true walls. They

are highly resistant and survive for many years. Spores are dispersed by air

currents.

PRØTØZØÅÑS

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They are heterotrophs (predators or parasites).

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They are the primitive relatives of animals.

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There are 4 major groups of protozoans:

They live in fresh water, sea water or moist soil. They

move and capture prey by putting out pseudopodia

(false feet), e.g., Amoeba. Marine forms have silica

shells on their surface. Some of them are parasites, e.g.,

Entamoeba.

ÅMØËBØÏD PRØTØZØÅÑS