Protists and Fungi

Chapter 21 & 22

•Most diverse organisms

•Eukaryotic

• Mostly Unicellular Some multicellular

•Mostly Microscopic

•Asexual & Sexual Reproduction

•Heterotrophic (must eat) or

autotrophic (produce own food)

•Animal like - protozoans

•Plant like – algae – produce a large amount of worlds oxygen

Kingdom Protista – Chapter 21

Structures• Ectoplasm – thick cytoplasm• Pellicle – hard outer covering• Macronucleus and micronucleus• Contractile vacuole for

osmoregulation• Trichocyst – for protection• Gullet – food entry• Eyespot – sensitive to light• Chloroplast - photosynthesis

Besides a chloroplast, what protozoan

structure would be necessary for a

photosynthetic protist (also called algae)?

eyespot

Protozoan Diversity•Most species live in water•Grouped by method of movement

–Pseudopods – false feet; cytoplasmic extensions (amoebas)

–Flagella – whip-like tail (Flagellates)

–Cilia – small hairs (Ciliates)•Reproduction methods – look over

pgs. 462 & 463–Asexual & Sexual

What common function do pseudopodia, cilia, and flagella share in

protozoa?

movement

How do multicellular

algae differ from plants?

they do not have roots, stems, or

leaves

Amoebas - pseudopod

s

Paramecium - cilia

Trypanosomes - flagellates

Plasmodiumspore formers

Algae: Green, Red & BrownPhotosynthetic

Diatomsunicellular, photosynthetic unique double

shells made of silica, move by gliding

Stentor

Vorticella- cilia

amoeba

euglena

paramecium

Protozoan Diseases

Amoebic dysentery– Warm climates,

poor sanitation– Live in and destroy

intestines– Extreme diarrhea

filled with pus and blood, liver and brain lesions

• Plasmodium vivax– Malaria– In the saliva of the female

anopheles mosquito– Shaking, chills, fever, jaundice

(yellow skin), liver destruction, vomiting, seizures, blood in urine

Based on: Scientific American, June 1978

Adult Female Mosquito

Feeds on blood for protein to make eggs

Distribution of Malaria

Based on: U.S. News & World Report, January 1997

Risk of Malaria: 1946, 1966 & 1994

Historic Efforts to Defeat Malaria

• Drained wetlands to reduce habitat for mosquito reproduction– But we lost important wetlands

• Control of mosquitoes using pesticides– But mosquitoes developed

resistance• Drugs (chloroquine) to protect

humans against infection by Plasmodium– But Plasmodium developed

resistance

• Leishmania – Carried by sand flies, rodent

reservoirs– Tropical disease– Severe skin lesions

• Trypanosoma brucei– African Sleeping Sickness– Tse-tse fly, wild animal reservoirs– Necrosis (tissue death) of lymph

tissue, nervous disorder

Overview of Kingdom Protista– Diversity – Most Diverse of all organisms– Live in moist or aquatic environments either free-living or

parasitic– Mostly unicellular, but some like kelp are multicellular– Some are photosynthetic others heterotrophic– Asexual and Sexual Reproduction– Grouped by methods of locomotion– Can be fungi-like, plant-like or animal-like (protozoans)– 1st eukaryotic cells – these characteristics, which are found

in many eukaryotes, first evolved in protist– Include: Algae, Amoebas, Diatoms, Dinoflagellates,

Euglenas, Paramecium, Sporozoans

Fungus – Chapter 22

• Eukaryotic• Spores• External digestion• Live in or on the host• Warm moist climates• Functions: decomposition, food

production, drug and antibiotic synthesis

• Oral or topical anti-fungals inhibit chitin formation

• Mostly a problem for immunocompromised

Fungal Structures• Thallas – body• Cell wall – made

up of chitin• Hyphae –

separated by septa

• Mycelium - mass of hyphae

• Fragmentation – breaking off part

Fungal Digestion

• Use hyphae• Release digestive enzymes• Food is dissolved outside of

fungi• Absorbed by mycelium

Fungal Diseases• Candida

– Yeast infections– Normal flora,

hospital pathogen– Head, hands,

genitals and mouth (thrush)

– White patches, itching, irritation, slimy layer, bread smell

They have a cell wall, which some antibiotics destroy.

Why would antibiotics

sometimes work on fungal

infections?

• Aspergillosis– Causes allergic reaction in body– Coughing up blood, weezing, weight

loss– Affects immunocompromised– Fungal balls in the lungs, surgical

removal– Dead leaves, compost piles

• Tinea– Cutaneous mycosis– Ringworm, athletes foot– Red ring like rash, itching,

peeling– Topical cream for most cases

Overview of Kingdom Fungi• Eukaryotic & Heterotrophic• Contain chitin• Obtain nutrients by secreting digestive enzymes and absorbing the

decomposed nutrients from their environment• Important resource recycler• Most reproduce by releasing spores that are produced asexually

and sexually• Exhibit nuclear mitosis – nuclear envelop remains through mitosis• Mostly multicellular,a few unicellular (yeast)• Filamentous bodies• Classified by reproductive structures• Some are harmful• Mutualistic relationships: Mycorrhiza – fungi & plant roots

Lichens- fungus & photosynthetic partner• Include: Mushrooms, Molds, Yeast