Chapter 28 Notes

Protists

Protists

Protists exhibit more structural and functional diversity than any other group of organisms.- all are eukaryotic- most are unicellular, but some are colonial or multicellular

Protists

Protists

Protists are divided into 3 categories:

- Animal-like are heterotrophs which consume other organisms.

- Plant-like make their own food through photosynthesis just as plants do.

- Fungus-like acquire their nutrients by decomposing dead organisms.

Protists

The large diversity in protists is a result of endosymbiosis- early eukaryotes were the result of acquiring mitochondria- a second acquiring of photosynthetic cyanobacteria which evolved into a plastid; led to photosynthetic algae

Protists

Protists

Protists can move in different ways: - by using a tail-like structure

called a flagella - through the use of cilia, which

are short, hair-like structures that cover the cell surface

- by using a fake foot, or pseudopod

Protists

Animal-like protists are often referred to as protozoa. - some animal-like protists are parasitic and cause diseases such as malaria and African sleeping sickness.

Protists

Protists

Plantlike protists -can be one-cell or multicellular - can live in soil, on trees, and in both fresh water and salt water. - do not have roots, stems, leaves

Protists

Protists

Euglenoids- single-celled organisms that swim

using flagellaDinoflagellates -single-celled protists that are

primarily marine plankton

Protists

Diatoms-single-celled algae that releases into

the environment approximately half of the oxygen that we breathe.

Algae- green algae are multicellular, and

contain chlorophyll, but they are not considered plants because they don’t have roots, stems, or leaves.

Protists

Protists

Funguslike Protists- Oomycetes- have hyphae but cell walls are made of cellulose, not chitin- usually have flagella - do not carry out photosynthesis; instead are parasites or decomposers

Protists