Cells
and
Microorganisms
1
Do You Know the
Differences Between a
Plant and an Animal Cell?
Discuss this with a neighbor and be prepared to
share your answers with the class.
Georgia Performance Standards
• S5L3. Students will diagram and label parts of various cells
(plant, animal, single-celled, multi-celled).
• a. Use magnifiers such as microscopes or hand lenses to
observe cells and their structure.
• b. Identify parts of a plant cell (membrane, wall, cytoplasm,
nucleus, chloroplasts) and of an animal cell (membrane,
cytoplasm, and nucleus) and determine the function of the
parts.
• c. Explain how cells in multi-celled organisms are similar and
different in structure and function to single-celled organisms.
• S5L4. Students will relate how microorganisms benefit or
harm larger organisms.
• a. Identify beneficial microorganisms and explain why they are
beneficial.
• b. Identify harmful microorganisms and explain why they are
harmful.
Did you know that you and oak trees are both made of
cells? A cell is a tiny part of a living thing.
•Are we like plants? How are plant cells and animal cells
alike?
• Plant cells have more parts than an animal cells
• BUT- both kinds of cells take in nutrients and get rid of
wastes.
•Reading Connection: What kind of text structure would
best represent the information?
Let’s look at a plant cell up close!
Cell Form and Function
https://app.discoveryeducation.com/learn/videos/F4413B9F517B-4A36-9E81-2D89AB5667DE?hasLocalHost=false
Plant Cell
•The plant cell is surrounded by a cell wall.
This stiff wall protects the cell.
•Why do you think plants need stiff walls?
•Just inside the cell wall is the cell membrane
• This thin membrane allows water and
nutrients to pass into the cell.
• It allows wastes, including oxygen, to pass
out of the cell.
•The cell membrane stops some materials from
entering the cell and injuring it.
•Look at the next slide for an illustration.
Plant Cell
Vacuole
Nucleus
The nucleus
controls the
cell’s growth.
The plant’s
genes are
stored here.
Cell membrane
Cell wall
Cytoplasm
The rest of the
plant cell is filled
with cytoplasm,
which is much
like jelly. Much
of the cell’s
work takes
place here.
Chloroplast
Green chloroplasts produce food for the plant.
The chloroplasts combine sunlight, water, and
carbon dioxide from the air to produce sugars,
which give the plant energy to grow and bloom.
Plant Cells
Plant Cell- Can you
identify the parts?
???:
Located near
the center of
the cell – the
plant’s genes
are located
here
???:
Stores food, water, or
wastes
???:
Jelly-like
substance that
fills cell
???:
Produces food
for the plant
???:
Thin membrane
allows water and
nutrients to pass
into the cell and
allows wastes,
including oxygen, to
pass out of the cell
???:
Protects and supports
the plant
2
Animal Cell
Do plant and animal cells have the same parts?
• Cell membrane – has same job in both cells
• Also protects the cell from harmful
substances.
• The nucleus controls the cell’s growth and
contains genes.
• The nucleus is surrounded by cytoplasm
• What is cytoplasm?
• See next slide for an illustration
Animal Cell
Cytoplasm:
Jellylike
substance
that fills the
cell
Nucleus:
Controls the
cell’s growth
and contains
its genes
Cell membrane:
Allows materials to move
in and out of the cell and
protects cell from harmful
substances
•Why don’t animal
cells have cell walls?
•With no cell walls,
animal cells can take
different shapes and
can develop in
different ways
• Animal cells can
become nerve cells,
muscle cells, blood
cells, and so on.
Having different kinds
of cells has allowed
animals to develop
muscles, bones, and
nerves have given
animals the ability to
move from place to
place.
Animals Cells
Animal Cell- CAN YOU
IDENTIFY THE PARTS?
Muscle cells
Bone cells
???:
Jellylike
substance that
fills the cell
Liver cells
???:
Controls the
cell’s growth
and contains
its genes
???:
Allows materials to
move in and out of
the cell and
protects cell from
harmful substances
Cells
cell structure
Reading connection: What clue words let
you know that the author is showing you
a contrast (differences) in the two cells?
The illustrations below show some of the shapes that animal cells
can take. On the other hand, most plant cells have square
shapes. Their stiff cell walls prevent that shape from
changing. However, the cell walls do serve as the plant’s
“skeleton”. They support the plant.
bone cells
Liver cells
muscle cells
fat cells
•Animal cells do not have chloroplasts. Animals cannot produce their own
food, so they don’t need them! They must get their energy by eating plants,
other animals, or both. Animals must depend on plants and animals that they
eat to survive.
•Animal cells tend to be smaller than plant cells. However, you will need a
microscope to see either one. The largest plant cell is only about 100
micrometers wide. A micrometer is 1/1,000,000 meter (1/25,000 inch). That’s
tiny!
Let’s summarize:
Animal Cell - Functions
Nucleus
control center of the cell –
stores information for cell
functions
Cytoplasm
jelly-like substance where
cell activities take place
Cell membrane
thin, controls the
substances that enter or
exit the cells
Let’s summarize:
Plant Cell - Functions
Nucleus
control center of the cell – stores
information for cell functions
Chloroplasts
contain green pigment chlorophyll,
needed in photosynthesis
Cytoplasm
jelly-like, where cell activities take
place
Cell membrane
thin, controls the substances that
enter or exit the cells
Cell wall
stiff wall which gives plant cells their
shape
What are the Differences
Between Plant Cells and Animal
Cells? Tell your neighbor.
Plant Cell
Animal Cell
•Plant cells contain
chloroplasts to make
food from solar energy
during photosynthesis.
•Animal cells DO NOT
contain chloroplasts.
•Plant cells contain cell
walls.
Animal cells DO NOT
have cell walls.
Review Question 1
Which of these is NOT made of cells?
A. a rock
B. an ant
C. moss
D. a stick
A.
Review Question 2
Which part is NOT found in an animal cell?
A. cytoplasm
B. Cell wall
C. Cell membrane
D. nucleus
B.
Review Question 3
Which statement is true?
A. The nucleus gives the cell its shape.
B. Plant cells are filled with jelly-like
chloroplasts.
C. An animal cell can become a bone cell.
D. A plant cell can become a nerve cell.
C.
Review Question 4
Which statement is true?
A. The cell wall allows materials to pass in and out of
cells.
B. Both plant and animal cells have a cell membrane.
C. The genes for plant cells are in the cytoplasm.
D. A plant cell produces food in its nucleus.
B.
Lesson 2: Single Celled and Multi-Celled Organisms
•Both plants and animals-made of one cell or millions of
cells like you.
•One-celled organisms are different…
•Some one-celled creatures have a nucleus; some don’t.
Some single-celled plants have chloroplasts, but do not
have stiff cell walls.
•All single-celled organisms eat, get rid of wastes, and
reproduce.
Single Celled and Multi-Celled Organisms
Single Celled and Multi-Celled Organisms
Fox News Video
Clip Brain Eating
Amoeba Causes
Death
Amoebas
Amoebas
are singleCheck out these
amoebas eating!
celled or
one-celled
organisms.
Cytoplasm
Amoebas are a kind of animal. They live just about
anywhere! You can find them in pond water, saltwater, moist
soil, and in animals… including you!!!!!!!!!!!!!! Notice that
their cell structure is a lot like yours.
• The amoeba “breathes” when oxygen passes through the
cell membrane into the cytoplasm.
Single Celled and Multi-Celled Organisms
Algae
•Algae are like plants.
• They live in the water and other moist places. Some algae have only
one cell.
•That includes the billions of algae that float on the surface of the
ocean.
•Seaweed is a form of algae that has many cells. Some seaweed
Single Celled and Multi-Celled Organisms
Algae
•They have a cell membrane, cytoplasm, and a nucleus.
•They are not surrounded by a stiff cell wall, but they do
contain chloroplasts to make food for themselves.
•Algae produces much of the oxygen in the air you
breathe.
• In fact, algae produces more oxygen than all the other
plants combined.
Single Celled and Multi-Celled Organisms
Bacteria
• Bacteria are one-celled organisms.
•We did not even realize that they exist until
the microscope was invented in the 1600s.
•There are more bacteria than any other kind of
living thing.
•A handful of soil can contain billions of
bacteria.
•Bacteria have NO nucleus.
•The material that is in the nucleus of other
cells is spread throughout the cytoplasm in
bacteria.
Bacteria
•They are the oldest form of life on Earth.
• They live EVERYWHERE on Earth from
the Arctic to the bottom of the ocean.
• Some bacteria are helpful and some are
harmful.
• You’ll learn more about the different types
of bacteria in the next slides.
Bacteria
Review Question 1
Which part does an amoeba NOT have?
A. chloroplasts
B. cell membrane
C. cytoplasm
D. nucleus
A
Review Question 2
Which of these produces most of the oxygen on
Earth?
A. amoebas
B. bacteria
C. Algae
C
D. Multi-celled plants
Review Question 3
How are single-celled algae different from multicelled plants?
A. These algae do not have stiff cell wall.
B. These algae have no chloroplasts.
C. These algae have a nucleus.
D. These algae have a cell membrane.
A
Review Question 4
How do you know that bacteria can reproduce
easily?
A. They have no nucleus.
B. They number in the billions.
C. We need a microscope to see them.
D. They come in many shapes and sizes.
B
What are cells?
Plant vs. Animal
Single-Celled and Multi-Celled Organisms
Discuss these with a neighbor.
Are there more single-celled (or one-celled)
organisms or multi-celled organisms? What
are we???
Discuss types of single-celled organisms we
have learned about.
Lesson 3: Helpful and Harmful Microorganisms
A microorganism is a living thing that is too small to see without a
microscope.
What else is too small to be seen without a microscope?
Microorganisms include amoebas, algae, bacteria, and other tiny
organisms. Do you remember the importance of bacteria and algae
and why they are known for?
Some microorganisms help, while others can make animals and plants
sick.
Can you figure out why???
Helpful and Harmful Microorganisms
Harmful Microorganisms
Salmonella
E. coli
Staph
•Some harmful bacteria, such as Salmonella and E. coli, can make you
very sick.
• These bacteria are found on raw chicken and other meat, raw eggs,
and other foods. If foods with bacteria on them touch other foods,
such as lettuce, the bacteria can spread to the lettuce.
•Cooking kills these bacteria.
• However, if cooked food is left out of the refrigerator for 2 hours or
longer, harmful bacteria will start to grow on it.
Helpful and Harmful Microorganisms
Harmful Microorganisms
Salmonella
E. coli
Staph
•You probably have staph bacteria on your skin right now!
• It can cause serious infections of the blood, bones, and
lungs.
•Have you ever had Strep throat?
•It was caused by strep bacteria and can lead to serious
diseases.
Helpful and Harmful Microorganisms
Harmful Microorganisms
Vomiting
Virus
Cold
Virus
•A virus is another
microorganism that causes
diseases.
•Even smaller than bacteria
• It must use a living cell
to grow and reproduce.
•Viruses cause many
diseases, from colds to
AIDS.
• Viruses often change as
they reproduce.
• A medicine that killed
the first virus often cannot
kill the changed virus.
AIDS
Virus
Helpful and Harmful Microorganisms
Harmful Microorganisms
Bakers yeast
•A fungus is a microorganism (the plural of fungus is fungi)
•Like plants, fungi cannot move around
•Like animals, fungi cannot make their own food
• They get their energy by eating other living or dead
organisms.
Helpful and Harmful Microorganisms
Harmful Microorganisms
Bakers yeast
•Kinds of fungi include molds, yeasts, and mushrooms.
• Some kinds of fungi, such as yeast, contain only one cell.
Others, such as mushrooms, are multi-celled.
•You have probably seen mold growing on food.
•Each bit of mold is very small, but when mold grows in large
groups, you can see it.
Helpful and Harmful Microorganisms
Harmful Microorganisms
•Harmful mold and other fungi can spread through crops
and kill them.
•They can also rot food and wood.
• Fungi cause several skin diseases-including athlete’s foot
and ring worm (which is not really caused by a worm).
10
Helpful and Harmful Microorganisms
Harmful Microorganisms
•What does algae give us, and why is it important?
•Even algae can be harmful. “Red tide” in a lake or ocean is
caused by a kind of algae that grows very fast (has nothing to
do with tides, though)
10
Harmful Microorganisms
Helpful and Harmful Microorganisms
Helpful Microorganisms
•We CANNOT LIVE
without
microorganisms.
• Without the algae and
other tiny plants floating
in the ocean, we would
not have enough oxygen
to stay alive.
Tell your neighbor
why…
11
Helpful and Harmful Microorganisms
Helpful Microorganisms
•Algae and other plankton
(microscopic plants and
animals) float on the surface of
the ocean.
• Tiny fish eat the plankton.
Then larger fish eat the tiny
fish.
•In time, people eat the larger
fish. So… an important food
source- fish – depends on
microorganisms! Get it?
•Review some helpful
microorganisms with your
neighbor.
How can you use
context clues to
help you with an
unfamiliar word on
this slide?
12
Helpful and Harmful Microorganisms
Helpful Microorganisms
•Microorganisms also help plants grow on land.
•Certain fungi help plants take up nutrients from the soil.
•Without these nutrients, the plants would not grow as well.
• That would mean less food for us and other animals.
•HOW?
13
Helpful and Harmful Microorganisms
Helpful Microorganisms
More Than Just Dirt!
There are over four billion
microorganisms in a teaspoon of healthy
soil.
13
Helpful and Harmful Microorganisms
Helpful Microorganisms
•Microorganisms help
provide us with other
kinds of food.
• Bacteria turn milk into
yogurt.
• In fact, one gram of
yogurt can contain up to
1 billion bacteria. (It’s
supposed to!)
•Bacteria also help
produce certain kinds of
cheese. Yeast makes
bread, rolls, and cakes
rise.
14
Helpful and Harmful Microorganisms
Helpful Microorganisms
Certain bacteria
in our bodies
helps digest our
food.
Drug companies
began producing
penicillin in 1943,
but only four years
later, bacteria
appeared that could
resist it (fight it off).
New bacteria that
can resist penicillin
are still appearing.
Scary, huh?
Some medicines such
as penicillin (which is
made from mold) and
Streptomycin (which
is made from bacteria),
help treat or cure many
diseases.
Helpful and Harmful Microorganisms
Helpful Microorganisms
•Microorganisms make
dead things decay.
•Without them, the Earth
would be covered with a
very thick layer of dead
plants and animals. YUK!
Rotting wood
•Without microorganisms, we would have trouble eating any
food.
•Certain bacteria in our bodies help digest food.
• Our survival depends on the helpful microorganisms in and
around us!
•Discuss the many ways that we depend on helpful
microorganisms with a neighbor.
Helpful Microorganisms
•Some microorganisms
help remove harmful
wastes from sewage at
water treatment plants.
•Others help clean up oil
spills.
Review Question 1
How can mold be helpful?
A. It grows on bread and other food.
B. It helps dead plants decay.
C. It is a kind of fungus.
D. It grows on wheat plants.
B
Review Question 2
Which statement is true?
A. Microorganisms cause disease.
B. Microorganisms cure disease.
C. Some microorganisms are eaten.
D. Microorganisms are rare.
A
Review Question 3
Why are bacteria grouped with microorganisms?
A. Both cause diseases.
B. Both cure diseases.
C. Both are single-celled.
D. Both are harmful.
A
Review Question 4
How can you avoid touching microorganism?
A. Make sure your meat is well cooked.
B. Wash your hands thoroughly many times a day.
C. Do not touch any soil.
D. You can’t avoid touching microorganisms.
D