Chapter 8

Protists & Fungi

Ch 8.1 - Protists

A. Protists – eukaryotic one or many-celled organism that live in a moist or wet environment

1. Protists are difficult to classify; they are usually grouped based on characteristics shared with plants, animals and fungi

B. Plant-like Protists are called Algae

1. They contain chlorophyll and make their own food

2. Examples:

a) Diatoms – found in fresh and salt water; make glasslike boxes

b) Dinoflagellates – use flagella (sing.flagellum) long, thin, whip-like tails to move in their environment

c) Euglenoids – have characteristics of both plants and animals (produce food & move)

d) Red, Green and Brown Algae – AKA seaweeds, are usually many-celled organisms that live at various depths in the ocean and contain chlorophyll or other colored pigments to make food

Green Algae

Brown Algae

Red Algae

3. Uses of algae: food, cosmetics, lotions, tires

C. Animal-like protists are called protozoans, and are classified by how they move

1. Ciliates – use threadlike structures called cilia that extend all around their cell memb.

Ex: Paramecium

2. Flagellates – move by whipping their long flagella

Ex: Euglena

3. Some move and eat using “false feet” called pseudopods, which are temporary extensions of the cytoplasm

Ex: Amoeba

4. Many protozoans are important sources of food for small animals but some are pathogens that can cause disease in humans

Ex: Giardia

D. Fungus-like protists

1. Like fungi they get energy as decomposers and reproduce with spores

2. Unlike fungi they have they are mobile

3. Some are good b/c they break down dead organisms but others can cause disease in plants and animals

4. Examples:

a) Slime Molds – found on decaying vegetation in moist, cool areas

b) Water Molds – live in wet places and can attack fish or feed on dead ones

c) Downy Mildews – can weaken or kill plants; this was responsible for the Irish potato famine of the 1840’s

Ch 8.2 - FungiA. Fungi can be food sources, can grow on

spoiling food or damp places or can cause infections

Ex: mushrooms, mold, mildew, ring worm, athlete's foot

1. Scientists are not sure how fungi are related to other organisms in evolutionary history

a) Some cause disease but others produce medicines

b) Many are important decomposers b/c they are saprophytes that feed on dead material

c) Most grow anchored to the soil like plants but cannot make their own food

d) Fungi can reproduce both sexually and asexually

B. Lichens are organisms composed of a fungus and either a green algae or cyanobacterium

1. They live together in symbiosis where each benefits from living with the other

a) The fungus gets food made by the algae and the algae has a protected place to live in the fungus

2. They can appear crusty or leafy and grow upright

3. Lichens can be an important food source for animals

4. Lichens help weather or break down rock to form soil

5. Lichens are very sensitive, so they can help scientists monitor pollution levels