WARM-UP:

What molecule is split during the light reaction of photosynthesis?

KINGDOM PROTISTA• Eukaryotic - most unicellular; complicated internal structure.• Divided by mode of nutrient acquisition

•plant-like: autotrophic; algae (including seaweed), diatoms•animal-like (aka protozoa) – heterotrophic; internal digestion. Some parasitic (malaria) • Further classified by motility.• Flagellated (Giardia), Euglena has characteristics of plant & animal • Ciliated (Paramecia, Euplotes) • Amoeboid (amoeba species) – use pseudopods or “false feet”

• fungus-like (slime molds, etc.) – heterotrophic with absorptive (external) digestion. Includes many common plant pathogens such as Phythophthora, cause of the Irish Potato famine

ANIMAL-LIKE PROTISTS: PROTOZOA COMMON EXAMPLES INCLUDE PARAMECIA AND AMOEBA

ANIMAL-LIKE PROTISTS:

Most are free-living. These are classified by movement: amoeba-like, ciliated, or flagellated.

Zoomastigina - flagella Ciliophora - cilia Sarcodina - pseudopods Sporozoa - Non-motile

Some are parasitic. Ex: Plasmodium which

causes malaria. See life cycle page 503 in textbook.

AMOEBAS IN ACTION

ANIMAL-LIKE PROTISTS: CILIATED

Cilia beat in a synchronized pattern to cause movement. Example: Paramecium

Paramecium is a typical ciliate. It has a gullet to swallow food, and a contractile vacuole to get rid of excess water.

Genetics: the DNA used for sexual reproduction is stored in the small micronucleus. A copy of this information is used to run the cell.

ANIMAL-LIKE PROTISTS: FLAGELLATED

Flagellates with long whiplike hairs that propel the cell.

Some nasty parasites are flagellates, including –

*Giardia lamblia, which causes diarrhea and is found in most surface waters of the US.

*Trypanosoma brucei, which causes sleeping sickness in Africa.

*Trichimonas vaginalis, an STD

ANIMAL-LIKE PROTISTS: SPOROZOANS

Non-motile animal-like protists

Live part of their life cycle inside the cells of hosts; ie, parasitic

Ex: Plasmodium which causes malaria which kills 1-2 million people each year.

Mosquitoes are the vector.

Plasmodium reproduces sexually in mosquito gut and asexually inside the human red blood cells, destroying them as they leave.

PLANT-LIKE PROTISTS

Commonly called ALGAE. Many different pigments affect

color. Rhodophyta is red, chrysophyta is gold.

Green algae are haploid most of their life cycle, with only a very short diploid phase. Called “alternation of generations:

Autotrophs. Most of the oxygen we breathe came from algal photosynthesis.

Very important commercial uses. Thickener (algin) Most are single-celled, but a few form

large multicellular seaweed species. Some used in food preparation (sushi, agar)

Some (like diatoms)have calcium carbonate (chalk) or silica shells.

Important applications for gardeners

What is an “algal

bloom” and why does

it kill fish?

MULTICELLULAR ALGAE commonly called seaweed can be classified as red, brown,

and green algae. All have chloroplasts, but the pigments in the chloroplasts vary, giving the different colors.

Some, like kelp, are very large and contain several different types of cells and tissue. These include leaves for photosynthesis, gas-filled bladders for buoyancy, the root-like holdfast, and tubes to transport nutrients throughout the body.

Algae contain the polysaccharide “agar”, which is tasteless and is used to thicken foods such as soft ice cream.

EUGLENA: THE MISSING LINK??

Has features of a plant … chloroplasts Allows it to make its

own food Has features of an

animal … “eyespot” to detect

light vs dark “flagellum” allows it

to move

FUNGUS-LIKE PROTISTS

Include water molds and slime molds Heterotrophic; many are

decomposers of dead organisms. Unlike fungi, the fungus-like protists

produce motile (moving) cells during part of their life cycle. Also, these protists surround and engulf bacteria as food.

Slime molds live as separate cells most of their lives, feeding on bacteria. When conditions get harsh, they aggregate into a multicellular slug, which migrates to a new location. The slug then forms a fruiting body that generates spores. The spores from the fruiting body are very hardy.

Multinucleate plasmodium. Resemblesanimals in that it is motile andengulfs its food.

PHYSARUM POLYCEPHALUM (SLIME MOLD)

FUNGUS-LIKE PROTISTS Include some of the worst

plant diseases (downy mildew, etc.)

Phytphthora infestans causes rot in plants. In the 1840’s, Phytophthora caused the potato blight in Ireland.

Caused crop failures over several years, resulting in famine, death and emigration.