Chapter 6 – Protists and Fungi
Section 1 – Protists
Key Terms
o
o
o
o
o
o
o
o
o
o
Protist – a eukaryotic organism that cannot be classified as an animal, plant, or fungus
Protozoan – animal-like protist
Pseudopod – temporary bulge of the cell used for movement
Contractile Vacuole – the cell structure that collects extra water from the cytoplasm and
then expels it from the cell
Cilia – tiny hair like extensions that move together in a sweeping motion
Symbiosis – a close relationship between two organisms in which at least one of the
organisms benefits
Mutualism – a type of symbiosis in which both partners benefit from living together
Algae – plantlike protist
Pigment – a chemical that produces color
Spore – a tiny cell that is able to grow into a new organism
 What are the characteristics of animal-like, plant-like, and funguslike protists?
Describe diatoms.
Beautiful, delicate structures: unicellular: live in fresh and saltwater: “Jewels of the Sea”:
food sources for many marine organisms
1. What is a Protist?
a. Protists are eukaryotes that cannot be classified as animals, plants, or fungi.
b. Why can you think of protists as the “odds and ends” kingdom?
They are different and do not fit completely in any other classification
c. What do all protists have in common? They all live in moist surroundings: all
eukaryotes
d. What word best describes protists? Diversity or diverse
What does that word mean? Many unique characteristics
 Most protists are unicellular, but some are multicellular
 Some are heterotrophs, some are autotrophs, and others both heterotrophs and
autotrophs
 Some protists cannot move, while others zoom around in their moist
surroundings
e. What are the three ways scientists classify protists? Animal-like, plant-like, and
fungi-like
 In what kind of environment do all protists live?
Moist surroundings
2. Animal-like Protist
a. How are animal-like protists like animals? Heterotrophs: most are able to move from
place to place to obtain food
b. What is an animal-like protist called? protozoans
c. Protozoans are unicellular
d. Protozoans are classified by the way they move and live
A. Protozoans with Pseudopods
 An amoeba belongs to the group of protozoans called sarcodines.
 Sarcodines move and feed by forming pseudopod
 Pseudopod means false foot.
 Amoebas use pseudopod to move away from bright light and to feed
 Sarcodines use pseudopod to trap food
 What problem do protozoans that live in freshwater have?
Small particles (water) pass easily trough their cell membrane into the cytoplasm
which could cause them to burst.
 How does an amoeba keep itself from bursting in water?
It contains a contractile vacuole that collects extra water and then expels it from
the cell
B. Protozoans with Cilia
 Ciliates have structures called cilia.
 Ciliates use their cilia to move with a wave-like motion.
 Cilia act like tiny oars to move the ciliate.
 An example of a ciliate is paramecium.
 A paramecium has two contractile vacuoles that expel water.
 It also has more than one nucleus, a large one for controlling everyday tasks and a
small one for reproduction.
 How do paramecia usually reproduce? Binary fission
 Sometimes they can reproduce by conjugation.
 What are cilia?
Hair like projections from cells that move with a wave like
motion
C. Protozoans with Flagella




Flagellates use flagella to move.
Some flagellates live inside the bodies of other organisms
Symbiosis is a close relationship in which at least one of the species benefits.
When both partners benefit from living together, the relationship is a type of
symbiosis called mutualism.
 Sometimes a protozoan harms its host. Giardia is a parasite in humans.
 Describe how a human might contract giardia.
Wild animals deposit giardia in freshwater streams, ponds, or lakes. When a
person drinks the water containing giardia, it attaches to the person’s intestines,
where they feed and reproduce. This causes serious intestinal conditions.
D. Protozoans That Are Parasites
 Parasitic protozoans are characterized by the way they live
 They feed on the cells and body fluids of their host
 They move in a variety of ways:
 Some have flagella
 Some depend on hosts for transport
 One even produces a layer of slime that allows it to slide from place to
place
 Plasmodium is a protozoan that causes malaria.
 Symptoms of malaria: high fever: severe chills
 What is symbiosis?
A close relationship between two organisms in which at
least one of the organisms benefits
3. Plantlike Protists
 Often called algae and are extremely diverse. Like plants, they are autotrophs.
Most use the sun’s energy to make their own food.
 Some are unicellular, while others are multicellular
 Still others are groups of unicellular organisms that live together in colonies
 Algae exist in a variety of colors because they contain many types of pigments
 Depending on the pigment, they may be green, yellow, red, brown, orange, or
even black
A. Diatoms
 Diatoms are unicellular protists with beautiful glasslike cell walls.
 Some float near the surface of lakes or oceans.
 Others attach to objects, such as rocks in shallow water.
 They are a food source for heterotrophs in the water.
 Many can move by oozing chemicals out of slits in their cell wall.
 When diatoms die, their cell walls collect at the bottom of oceans and lakes.
 This can be used as a pesticide or a polishing agent diatomaceous earth.
B. Dinoflagellates
 Unicellular algae surrounded by stiff plates that look like a suit of armor.
 All have two flagella held in grooves between their plates.
 Many glow in the dark.
C. Euglenoids
 Green, unicellular algae found mostly in fresh water.
 They have one animal-like characteristic - they can be heterotrophs under certain
conditions.
 When sunlight is available, most are autotrophs but when sunlight is not
available, they will act like heterotrophs by obtaining their food from their
environment.
 Euglenoids have a flagellum and an eye spot that helps them find sunlight.
D. Red Algae
 Contains red pigment.
 Most are multicellular seaweeds.
 Carrageenan and agar, are used in products such as ice cream and hair
conditioners
 In Asian cultures, it is a nutrient-rich food that is eaten fresh, dried, or toasted.
E. Green Algae
 Contains green pigments
 Most are unicellular
 Some form colonies
 And a few are multicellular
 Most live in either fresh or saltwater
 The few that live on land are found on rocks, in the crevices of tree bark, or in
moist soil
 They are very closely related to plants
F. Brown Algae
 Many of the seaweeds are brown algae
 They may contain these colors of pigments brown, green, yellow, and orange
 It has many plant-like characteristics
 holdfasts anchor the alga to rocks
 stalks support the blades
 blades are leaf-like structures
 bladders help the algae to float upright in water
 Some people eat brown algae. It can also be used as a thickening agent in pudding
and other foods
4. Funguslike Protists
 Funguslike protists are heterotrophs, have a cell wall, and use spores to
reproduce
A. Slime Mold
 Live on forest floors and other moist, shady places
 The ooze along the surfaces of decaying materials, feeding on bacteria and other
microorganisms.
 Some are so small that you need a microscope to see them and others may cover
an area of several meters.
 Slime molds begin their life as tiny, individual amoeba-like cells using pseudopod
to move around searching for food.
 After growing bigger, they join together to form a giant, jelly-like mass.
 When conditions become harsh, spore-producing structures grow out of the mass
and release spores
B. Water Molds and Downy Molds
 Most live in water or moist places.
 The often grow as tiny threads that look like fuzz.
 They attack many food crops, such as potatoes, corn, and grapes.
 More than one million people in Ireland died when a water mold attacked and
destroyed potato crops.

In what environment are water molds found?
in water or moist places
Section 2 – Algae Blooms
Key Terms
o Algae bloom – the rapid growth of a population of algae
o Red Tide – an algal bloom that occurs in saltwater
o Eutrophication – the build up over time of nutrients in freshwater lakes and ponds
that leads to an increase in the growth of algae
 What are the causes and effects of saltwater and freshwater algal
blooms?
 Algae blooms occur in both saltwater and freshwater.
 They occur when nutrients increase in the water
1. Saltwater blooms
 Salt water algal blooms are called red tides because the algae often contain red
pigments.
 They are not always red. Some are brown, green, and even colorless depending on the
species of algae that blooms.
 Dinoflagellates and diatoms frequently bloom in red tides.
A. Causes of Red Tides
 Red tides most often occur when there is an increase in nutrients in the water.
 Some occur regularly in certain seasons such as when the cold bottom layers of the
ocean that contain a lot of nutrients rise to the surface.
B. Effects of Red Tides
 Red tides are dangerous when the toxins that the algae produce become concentrated
in the bodies of organisms that consume the algae.
 Is it ok to eat fish or shellfish from a red tide? No Why or why not? The buildup of the
toxins in the fish or shellfish could lead to severe illness or even death

What determines the color of saltwater blooms?
The species of the algae that are in “bloom”
2. Freshwater Blooms
 A green layer on the surface of a pond is a sign of eutrophication.
 Eutrophication us a process in which nutrients, such as nitrogen and phosphorous build
up in a lake or pond over time, causing an increase in algae growth.
A. Causes of Eutrophication
 How can farmers or homeowners cause eutrophication? When farmers and
homeowners spread fertilizers on fields and lawns, some of the nutrients can run off
into nearby lakes and ponds.
 Sewage treatment plants can leak wastewater into the soil which could make it into
lakes and ponds.
B. Effects of Eutrophication
 List the serious consequences of eutrophication.
First, the layer of algae prevents sunlight from reaching plants and other algae beneath
the surface. Those organisms die and sink to the bottom.
Then, decomposers, such as bacteria, which break down the bodies of dead organisms,
increase in number.
Soon, the bacteria use up the oxygen in the water.
Without oxygen, fishes and other organisms in the water die. The only thing that will
survive is the algae.

What natural process of change occurs over time in a pond
or a lake?
eutrophication
Section 3 – Fungi
Key Terms
o Fungi – eukaryotic organisms that have cell walls, uses spores to reproduce, and is a
heterotroph that feeds by absorbing its food
o Hyphae – the branching, threadlike tubes that make up the bodies of multicellular fungi
o Fruiting Body – the reproductive structure of a fungus that contains many hyphae and
produces spores
o Budding – a form of asexual reproduction of yeast in which a new cell grows out of the
body of a parent
o Lichen – the combination of a fungus and either an alga or an autotrophic bacterium
that live together in a mutualistic relationship
 What characteristics do fungi share?
1. What Are Fungi?
 Fungi are eukaryotes that have cell walls, are heterotrophs that feed by absorbing their
food, and use spores to reproduce.
 The largest known organism on Earth is an underground fungus that covers an area as
large as a thousand football fields.




A. Cell Structure
The cells of all fungi are surrounded by cell walls.
Except for yeast, the cells of fungi are called hyphae.
The hyphae of some fungi are continuous threads of cytoplasm containing many nuclei.
Some hyphae are loosely tangled and some are tightly packed.
 Underground a mushroom’s hyphae form a loose, threadlike maze in the soil.

What do the bodies of multicellular fungi consist of?
Hyphae
B. Obtaining Food
 Describe how fungi obtain food. They absorb food through hyphae that grow into the
food source. The digestive chemicals ooze into the food and break down the food into
smaller substances that can be absorbed through the hyphae.
 Some fungi feed on dead organisms while others are parasites that break down the
chemicals in living organisms.
2. Reproduction in Fungi
 Fungi usually reproduce by making spores. Spores are produced in reproductive
structures called fruiting body.
A. Asexual Reproduction
 Most fungi reproduce asexually and sexually.
 When there is adequate moisture and food, they make spores asexually. Cells at the tip
of the hyphae divide to form spores. These spores grow into fungi that are genetically
identical to that of the parent.
 Unicellular cells undergo a form of asexual reproduction called budding, in which no
spores are produced. Instead, a small yeast cell grows from the body of the parent cell.
The new cell is genetically identical to the parent cell.
B. Sexual Reproduction
 Most fungi can also reproduce sexually when growing under unfavorable conditions.
 The hyphae of two fungi grow together and genetic material is exchanged. A new
reproductive structure grows from the joined hyphae and spores develop that will grow
into offspring that are genetically different from the parents.
C. Classification of Fungi
 Fungi are classified into three groups: club fungi, sac fungi, and zygote fungi.
 Sac Fungi – produce spores in structures that look like sacs. It is the largest group
including yeasts, morels, truffles, and some fungi that cause plant diseases.
 Club Fungi – produce spores in microscopic structures that look like clubs. It includes
mushrooms, bracket fungi, and rusts. It also includes puffballs. Club fungi are the most
poisonous.
 Zygote fungi – produces spores that can survive harsh environmental conditions. It
includes fruit and bread molds.

What is budding?
A form of asexual reproduction; it does not produce spores
3. The Role of Fungi in Nature
 Fungi play important roles as decomposers and recyclers on Earth. Many fungi provide
foods for people. Some fungi cause diseases while others fight disease. Still others live
in symbiosis with other organisms.
A. Environmental Recycling
 Many fungi are decomposers which break down the chemicals in dead organisms and
return them to the soil. Without fungi and bacteria, Earth would be buried under dead
plants and animals.
B. Food and Fungi
 Yeast is a fungus that is used in making bread and wine.
 Molds are used in the production of cheese. Some mushrooms are extremely poisonous,
so you should never pick or eat wild mushrooms.
C. Disease-Fighting Fungi
 Penicillium is a mold that prevents bacterial growth.
D. Disease-Causing Fungi
 Many fungi are parasites that cause serious diseases to plants. Dutch elm, corn smut,
and wheat rust are three such fungi.
 Some fungi cause diseases in humans. Athlete’s foot fungus causes an itchy irritation in
the damp places between your toes. Ringworm is another fungal disease, causing an
itchy, circular rash on the skin. Because the fungus produces spores at the site of the
infection, it can easily spread from person to person. Both diseases can be treated with
antifungal medications.

What is one way fungi help fight disease?
Fungi produce antibiotics that can kill bacteria.
E. Fungus-Plant Root Association
 How can a fungus help a plant grow larger and healthier? The hyphae of some
fungi grow into or on the plant roots and help the plant absorb water and
nutrients from the soil.

How do fungi help plants grow?
The hyphae of some fungi grow into or on the plant roots and help the
plant absorb water and nutrients from the soil.
F. Lichens
 A lichen consists of a fungus and either algae or autotrophic bacteria that live
together in a mutualistic relationship. How is this relationship “mutualistic”? The
fungus benefits from the food produced by the algae or bacteria and the algae or
bacteria obtain shelter, water, and minerals from the fungus.
 Why are lichens often called “pioneer” organisms?
They are the first organism to appear after a volcanic eruptions, fire, or rock slide.
 How are lichens useful as indicators of air pollution?
Many species of lichens are very sensitive to pollutants and die when pollutions
levels rise.

What two organisms make up lichen?
Fungus and either an alga or a bacterium