Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
7-3 : Characteristics of Protists
Engage: What do you know about protists?
Objectives:
1. Describe the characteristics of animal-like
protists, plant-like protists, fungus-like protists,
and examples of each.
7-3 : Protists
A. Characteristics
1.
2.
3.
4.
5.
6.
7.
8.
9.
Unicellular
Nucleus – Eukaryotes
“Odds and Ends “ Kingdom.
Definition: Single-celled organism that
contains a nucleus.
Examples: Diatoms, foraminifera, Amebas
Live:
Most
H2O environments.
Some
Moist soil.
Some
Parasites.
Individual & Colonies
1.5 billion years ago.
Autotrophs & Heterotrophs
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Viruses, Bacteria, Protists, and Fungi
10. Animal-like Protists
Plant-like Protists
Fungus-like Protists
B. Animal-like Protists
1. Protozoan -- “first animals”
a. Nucleus
b. No cell wall
like
c. Heterotroph
animals
d. Move
2. 4 Main Groups
a. Sarcodines
b. Ciliates
c. Zoo Flagellates
d. Sporozoans
C. Sarcodines
1. Sarcodines -- Have extensions of cell
membrane and cytoplasm known as
pseudopods.
2. Pseudopods -- “false foot”
function
Capture and engulf food
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Viruses, Bacteria, Protists, and Fungi
Movement
3. Shells -- Support & Protect
Example:
foraminiferans -- coins
Radiolarians -- look like
Christmas ornaments.
4. Ameba -- “blob-like”
a. Use psuedopods to move and to
obtain food.
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Chapter 7
Viruses, Bacteria, Protists, and Fungi
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Chapter 7
Viruses, Bacteria, Protists, and Fungi
b. Structure
 Cell Membrane -- Controls movement





c.
of particles -H2O, O2 , CO2 & wastes
Nucleus
Contractile Vacuole -- keeps the right
amount of H2O in its cell.
Food Vacuole – Digestion Waste elimination by vacuole joins
with membrane.
Cytoplasm
Psuedopod -- Movement and gathering
food.
Reproduction -- Cell Division.
Mitosis.
Ameba
Ameba
Ameba
d. Respond to stimulus -- Light,
chemicals.
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Chapter 7
Viruses, Bacteria, Protists, and Fungi
D. Ciliates
1. Ciliates -- Have small hair-like projections
called cilia on the outside of their cells.
2. Cilia –
 Act like tiny oars to move organisms
 Sweep food toward them
 Act as sensors.
3. Paramecium -- slipper-shaped.
a. Structure
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
Contractile Vacuole -- Controls H2O.
Micronucleus -- Small - conjugation.
Macronucleus -- Big - controls life function.
Oral Groove -- Indentation notch on side
(Mouth).
Gullet -- Funnel-like (Throat).
Anal Pore-- Empties waste
Trichocyst--Sharp spines - protection
Food Vacuole -- Digests food.
Pellicle -- Cell membrane - shape.
Cilia -- Hair-like projections.
b. Conjugation -- 2 ciliates temporarily
joined together -exchange part of their DNA.
c. Reproduction -- Splitting in half
crosswise. (See figure 6-11).
E. Zoo Flagellates
1. Zoo Flagellates -- Move by means of
flagellum.
2. Flagellum -- Long, whip-like structure that
propels a cell (moves).
3. Animal-like, plant-like or fungus-like.
Animal-like -- Zooflagellates.
Usually 1-8 flagella.
Sometimes 1000’s.
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
4. Live
a. Inside organisms -- symbiotic.
Example: termites -- intestines to
digest wood.
Parasitic
Example: Humans -- African sleeping
sickness -- tsetse fly.
5. Diseases
Trichomonas -- Infection female
reproduction system.
Giardia – Parasite in humans – attach to
intestines – Beavers – “Hikers disease”.
E. Sporozoans
1. Sporozoans -- Parasites that feed on
the cells and body fluid of their host
animal.
2. Spores -- Enable sporozoans to pass
from one host to another.
Spore Source -- Food, tick, mosquito.
3. Malaria -- “Plasmodium”
2 hosts -- Humans & mosquito.
Need both to complete the life cycle.
(Results -- high fever for 6-8 hours
every 48 hours for several weeks).
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
Plant-like Protists
A. Introduction
1. Most Unicellular
2. Algae
* 3. Autotrophs
a. Starts a lot of food chains
b. O2 production (70%)
4. Most are flagellates -- Move with
flagella.
5. Phytoflagellates
phyto = plant
6. 6 Groups
a. Diatoms
b. Dinoflagellates
c. Euglenoids
d. Red Algae
e. Green Algae
f. Brown Algae
B. Euglenoids
1. Green unicellular algae
2. Can be Heterotrophs & Autotrophs
2. Euglena
a. Pouch -- holds (2) flagella.
b. Eyespot -- red -- sensitive to light.
Why important?
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c.
Chapter 7
Viruses, Bacteria, Protists, and Fungi
Chloroplasts/grass-green structures for
food making.
C. Diatoms
1. In toothpaste
2. 10,000 species
3. Water-dwelling
4. Beautiful glasslike cell walls
5. Die – cell walls remain -- form deposits
(diatomaceous earth)
polishing agent -- scouring cleansers
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
D. Dinoflagellates - unicellular algae
1. Red Tides -- Dinoflagellates reproduce
so rapidly that the water becomes
colored by them (yellow-green) to
(orange-brown).
Dangerous -- Produce toxins that
can injure or kill living things.
2. Glow at night
3. Elaborate armored cell walls
4. Spin like a top - caused by 2 flagella
E. Red Algae
1. Multicellular seaweed
2. Several meters long -- not as big as
brown algae.
3. Attached to rocks on the ocean floor.
4.
260m
5. Accessory pigments able to absorb small
amount of light
transfer
chlorophyll
6. Uses
a. Food – Asian cultures
b. Fertilizer
c. Chemicals -- Manufacture certain foods
(ice cream) “Carrageenan” & “Agar”
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Viruses, Bacteria, Protists, and Fungi
F. Green Algae
1. Most unicellular
2. Fresh & Salt water or moist areas on land.
3. Green algae evolved into land plants.
G. Brown Algae
1. Seaweed
2. Sargassum -- Brown algae floats on
the ocean’s surface -- air bladders
keep them afloat.
“Sargasso Sea”
Home for many organisms.
3. Giant Kelp – Attach to sea floor.
4. Rockweed – Atlantic coast
5. Food -- People & livestock.
6. Chemicals from Brown Algae.
Algins or Alginates -- added to salad
dressing & other foods. Make them
smooth & prevent their ingredients
from separating.
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
Fungus-like Protists
1. Characteristics
a. Fungi – “sort of like” kingdom
b. Heterotrophs
c. Cell wall
d. Spores – for reproduction
2. 3 types
 Slime Mold
a. Life cycle -- moist, flat, shapeless
blobs that ooze slowly over dead
trees . . . “slime”
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
 Water Molds & Downy Mildews
a. Live in water or moist places.
b. Great Potato Famine in Ireland
1845-1846 (killed 1,000,000 people)
c. Can attack -- potatoes, cabbages,
corn and grapes.
d. Animals -- get diseases
(i.e., white spots of fins & mouth
of aquarium fish).
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
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Exploring Life Science
Chapter 7
Viruses, Bacteria, Protists, and Fungi
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