Protista• Simple eukaryotes• Diverse

– Unicellular

– Colonial habit– Simple multicelluar cells

• Aquatic• Algae � photosynthesizers• Others� eat bacterial or other small cells

Protista

• The first eukaryotic cells are thought to have been protists

• Aerobic organisms evolution

• endosymbiotic Theory.

Protista

• Nucleus� multiple DNA• Endomembrane systems• Organelles• Movement � flagella • Sensory Organelles � cilia• Reproduction sexual & asexual• Respiration � aerobic

The Kingdom Protista

• is divided into four major groups• Lifestyle

– the protozoans,– the slime moulds,

– the unicellular algae, – the multicellular algae

Some Major Groups

• The Chromobionts � brown algae and golden-brown algae

• The Chlorobionts are the green algae • The Rhodophytes ����Red algae• Rhizopod sarcodines � amoebae• The Ciliates• The slime moulds

Rhodophytes Red algae

• Photosynthetic

• Phycobilin, a pigment � redness.

• Coralline algae

Porhyra spp.

Corallina spp.

Alternation of generation

Green algae

• Chloroplasts

• Unicellular/colonial/multicellular

• Multicellular �Alternation of generation

Ulva � sea lettuce

Chromobionts

• brown, golden-brown, and yellow-green algae

• Photosynthetic components

• Cell walls containing silica• Life cycle� alternation of

generationsDiatoms, unicellular brownalgae encrusted with silica

Rhizopoda Sarcodina: The amoeba

• Rhrizopods � superclass– Eg Amoeba– Pseudopodia � temporary

extensions of the cytoplasm used in

locomotion and digestion

Ciliates

Paramecium

Cellular Slime Moulds

•Cellular Slime Moulds: Arasiomycota

•Exists a majority of its

life cycle as an amoeba

•In times of stress these amoebas unite to form a

Pseudoplasmodium,

which crawls to another location (slug form), and

forms a fruiting body

Lamproderma sp

Plasmodial slime moulds. • Myxomycota

• Not fungi• 1000 known species• Pigmented

• Can protect themselves

• Feed off organic matter

• Pseudopodia

• 2 stage life cycle

Fuligo septica

Fungi• Fungi are a kingdom of organisms which share the following

characteristics:

• Their main body is in the form of thin (one cell thick!) strands called mycelium

• They cannot manufacture their own food through photosynthesis; rather, the mycelium secretes enzymes which digest part of their surroundings (a log, for example) and this is then absorbed by the mycelium.

• Their cell walls are made mostly of chitin and similar compounds, not cellulose.

• They reproduce by means of spores.

Also: Water moulds oomycotaFungi imperfecti deuteromycota

Chytridomycota• Diverse• are mainly aquatic (sea,

rivers)• parasites/decomposers

• and have flagellated gametes

• have chitin, which strengthens the cell walls.

Club Fungi (Basidiomycota)

PorciniChanterelle

The Sac Fungi (Ascomycota)

• Poorly known• Yeasts• Edible morels• truffles

Morel

Conjugation Fungi (Zygomycota)

RhizopusSporangia of bread mould showing asexual reproduction

Conjugation Fungi (Zygomycota)

gametangial fusion

zygospores

Unispored sporangia

Multispored sporangia

Lichens (Mycophycophyta)

Deuteromycetes

• Imperfect fungi

• Not all disease causing

• P. roquefortii and P.camembertii

Oomycota

• Downy mildew

• Late potato blight• Egg fungi

• Not all harmful• Some � parasitic

and affect aquatic plants and organisms

Phytophthorainfestans