WARM-UP: What molecule is split during the light reaction of photosynthesis?

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. I ncludes many common plant pathogens such as Phythophthora, cause of the Irish Potato famine

 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.

 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.

 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

 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.

 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?

 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.

 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

 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. Resembles animals in that it is motile and engulfs its food.

 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. famine