2.18.11

Yunsu Y.

↑Parmecium ↑

Protists:

• Most protists are single celled, but there are still some that are multicellular.


• They are eukaryotes and more complex than prokaryotes.


• 2 Theories of how eukaryotic cells evolved :

1. All organelles evolved from inward folds of the plasma membrane or endocytosis. ----except mitochondria and chloroplast, because they have their own DNA.


2. Endosymbiosis

• developed by Lynn Margulis


• chloroplast and mitochondria evolved from small prokaryotes that established residenc within other, larger host prokaryotes.----the host cell may have injested theses for food and if remained alive, continued to perform respiration within cell.

• Like before, most are unicellular, but some are colonial or mulitcellular. (those two are different.)

1. 4 categories of protists:

• protozoans


• slime molds


• unicellular algae


• seaweeds

1. Protozoans

• Ingest food and have to live in the water, wet soil or watery enviornment inside animals.


• They have flagellates: one or more to move. Free living but some are parasitic


• Amoeboas: move by pseudopodia-extensions of cytoplasm.


• Forams: move with pseudopodia and components of limestone.


• Apicomlexans: all parasitic and named for an apparatus at their apex.


• Ciliates: use cilia to move and feed.

2. Slime molds:

• may look like fungi but not closely related.


• decomposers

3. Unicellular Algae:

• have chloroplast


• components of plankton-communities of organism, microscopic and drift or swim near surface of ponds and oceans.


• planktonic algae=phytoplankton


• 3 groups:

-Dinoflagellates: 2 flagella, blooms cause red tide.

-Diatoms: glassy cells walls with silica-used to make glass.

-Green algae: mostly in freshwater lakes and ponds. Most closely related to true plants but still towards the protists. Volvox is a colony of flagellated cells.

4. Seaweeds

• multicellular marine algae


• slimy rubbery substances that cushion bodies against waves


• Different colors like: green, red, brown


• Used fro food: found commonly in Asian food, soups, wraps, sushi.

-some have polysaccharides, humans cannot digest.

• Also used for thickeners: pudding, ice cream, salad dressing, and Gel agar in petri dishes.

After notes we worked on U.P pg 27-31, whatever that was not finished was homework.

HW: pre-lab U.P pg 39-43, be prepared on Monday, know what we are doing. Nature Due 3/4

Next Scribe: Davin L.