Transcript Chapter 8 - Maria Regina School

Chapter 8
Protists and Fungi
Protists
• Protist- one or many celled organism that lives
in moist/wet surroundings.
– Eukaryotic cells
– Asexual reproduction by cell division or sexual
reproduction with meiosis
Plant-like Protists
• Algae- plant like and contain chlorophyll
• Diatoms- found in fresh or salt water
• Dinoflagellates- have 2 flagellum, or long whip like
structures for movement
• Euglenoids- have characteristics of plants and animals
• Red algae- contain chlorophyll but produce red
pigment and can live 200m deep in ocean
• Green algae- contain large amounts of chlorophyll
• Brown algae- chlorophyll and brown pigment. Found in
cool, saltwater environments. Important food for fish
– Ex: kelp
Animal-like Protists
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Protozoans- one celled, animal like protists
Ciliates- have cilia to move around.
Flagellates- whip long flagella to move
Pseudopods- move and feed using temporary
extensions of cytoplasm
Diseases
• Protozoans that cause disease can be
transmitted by flies or biting insects or found
in contaminated water
Importance of Algae
• Produce oxygen during photosynthesis
• Are a food source for many organisms
Slime Molds
• Fungi-like protist that forms delicate, weblike
structures on the surface of their food supply
– Usually found on decaying logs
– Often brightly colored
Water Molds and Downy Mildews
• Fungi-like protists that lives in water or moist
places
• Grow as mass of threads over plant or animal;
• Some are parasites, decomposers
Importance of Fungi-like Protists
• Break down dead organisms
• Cause diseases in animals/plants
– Lesions in fish
• Caused the Irish Potato Famine during the
1840s
Fungi
• Many celled
• Hyphae- when body of fungus is mass of many
celled, thread like tubes
• Saprophytes- organisms that obtain food by
absorbing dead or decaying tissues of other
organisms
• Grow best in warm, humid areas
Fungi Reproduction
• Asexual and sexual reproduction use
production of spores
• Spore- waterproof reproductive cell that can
grow into new organism
Classification
• Classified into 3 groups
– Club fungi spores
produced in club-shaped
structure called basidium
– Sac fungi yeast, molds,
morels, truffles. Spores
produced in a little, sac like
structure called ascus
– Zygote fungi produce
spores in a round spore
case called sporangium on
tips of upright hyphae
Lichens
• An organism made of a fungus and either a
green algae or cyanobacterium
– Relationship where both benefits
• Cyanobacterium or algae get moist, protected place to
live
• Fungus gets food made by green algae or
cyanobacterium
– Important food source for animals like caribou and
musk oxen
– Help weather rock to create soil
Fungi and Plants
• Fungi interact with plant roots to form
network of hyphae and roots called
mycorrhizae
– Fungus helps plants absorb more of certain
nutrients from soil, while plant provides food and
nutrients to fungi
Importance of Fungi
• Food source (but can be poisonous!)
• Used to make cheese
• Yeast creates bread, alcohol (remember
fermentation!)
• Can cause disease that destroys crops or affects
humans (athlete's foot, ringworm)
• Can produce antibiotics like pencillin
• Decompose organic materials and return
nutrients to soil.