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Science 8
Biology Unit
Chapter 1 – Cells
KEY
Pages 4 – 39
Section 1.1 – Characteristics of Living Things
1. List the 6 characteristics of living things. Refer to Table 1 on page 5.
a)
b)
c)
d)
e)
f)
Are composed of cells and all cells are similar
Respond to the environment.
Have a life span.
Reproduce, grow and repair themselves.
Require energy.
Produce waste.
2. Define organism: an individual living thing
3. What are the two main ideas of the cell theory?
 All living things are composed of one or more cells.
 All new cells arise only from cells that already exist.
Section 1.2 – The Microscope (refer to pages 396 – 398)
1. Describe the method you would use to prepare a dry mount.
a) Place the object that you wish to observe in the centre a
microscope slide.
b) Hold a cover slip between your thumb and forefinger. Place the
edge of the cover slip to one side of the object and gently lower the
cover slip onto the slid so that it covers the object.
2. What is the difference between a dry mount and a wet mount? How do you put
the cover slip over an object when doing a wet mount? The difference between
a dry mount and wet mount is that a dry mount does not use water. You
will place 2 drops of water on the object then holding the cover slip with
your thumb and forefinger, touch the edge of the surface of the slide at a
45 degree angle and gently lower the cover slip, allowing air to escape.
3. What power setting should your microscope be on when placing a slide onto
the stage of a microscope? Low-power setting
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4. You first bring an image into focus using the coarse-adjustment knob. Why do you
not want the lens to touch the cover slip? You may move the cover slip and
therefore your object; you may smudge the lens; you make break the
lens; you make break the microscope lens.
5. Why do you place the object on the microscope slide facing the “wrong” way and
upside down? What happens when you move the object away from your body
while looking through the eyepiece? You place an object facing the “wrong”
direction and upside down so that it appears the “right” way and upright
when you look through the eyepiece. When you move the object away
from your body, it appears to be move towards you.
6. Define field of view: The circle of light you see when you look through the
eyepiece of a microscope. You will see your object within the field of
view.
7. How do you get an object to appear larger when using a microscope? What
adjustment knob would you use to bring the letter into focus? Rotate the
nosepiece to the medium-power or high-power objective lens. Use the
fine adjustment knob.
8. What steps do you use when storing a microscope?
a. Rotate the nosepiece to the low-power objective lens.
b. Remove the slide and the cover slip.
c. Clean the slide and cover slip, then return them to their appropriate
location.
d. Return the microscope to the storage area.
9. What is a stereo microscope or dissecting microscope? When would you use
this microscope? A microscope used to observe small 3-D objects. You use
this microscope when you cannot look at a sample on a slide. Ex. Live
specimens.
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Section 1.3 – Plant and Animal Cells
1. State the difference between eukaryotic and prokaryotic cells. Eukaryotic cells
are cells that have a nuclear membrane and prokaryotic cells are one-celled
organisms that where the nucleus is not surrounded by a membrane.
2. Animal Cell Structures – give the description and function for the following
cell structures as seen through a compound light microscope:
Cell Structure
Nucleus

Chromosomes

Cell Membrane


Cytoplasm

Description
Surrounded by a
membrane
Found inside nucleus
Surrounds the cell
Double layer of fat
molecules
Watery fluid that
contains everything
inside the cell.
Vacuole

Filled with fluid
Flagellum




Whip-like tail
Not found on all cells
Tiny hairs
Not found on all cells
Cilia
3. Draw Figure 2, page 11 in the space below.
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





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Function
Control centre
Directs all of the cell’s activities
Contains genetic information
(DNA); genetic info duplicated
and passed on to other
identical cells
Holds contents of cell in.
Controls movement of nutrients
in and wastes out.
Chemical activities occurs here
Allows materials to be
transported quickly in the cell
Stores wastes
Stores water and nutrients
Stores waste and excess water
Helps cells to move
Helps move a cell
Helps move fluid surrounding
the cell
4. Plant Cell Structures - give the description and function for the following cell
structures as seen through a compound light microscope:
Cell Structures
Vacuole

Cell Wall

Description
Same as animal cell,
except that it is much
larger
Thick outer wall
Chloroplasts

Contain chlorophyll

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Function
Stores water and nutrients
Stores wastes
Provides protection, extra
support, and strength.
Food factories
Chlorophyll allows plants to
make their own food using the
sun, CO2 and water.
5. List the similarities and differences between plant and animal cell structures.
Similarities – both have a nucleus, chromosomes, cell membrane,
cytoplasm and vacuole.
Differences – only some animal cells have flagellum and cilia, while plant
cells have much larger vacuoles, a cell wall, and chloroplasts.
6. Where in the cell do you find genetic information? Chromosomes contain
genetic information and are found in the nucleus.
7. Predict what might happen to a cell if the cell membrane was replaced by a plastic
covering that prevented molecules from entering or leaving the cell. The cell will
die because no nutrients can come in and there would be a build up of
waste products inside the cell (becomes toxic to the cell).
8. Cilia also function to remove dirt and debris. Where in the human body might you
find cells with cilia? Explain your answer. In your throat and lungs.
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Section 1.5 – Technological Advances of the Microscope
1. Complete the following chart on the different types of microscopes.
Type of Microscope
Single-Lens
Microscope
Compound Light
Microscope
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Transmission
Electron
Microscope
Scanning Electron
Microscope
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Capabilities
Was able to magnify
objects 10 X.
Able to see tiny organisms
2nd lens added; 2000X
magnification
Some organelles can be
seen
2, 000, 000 X
magnification
Uses beam of electrons
Can make a 3D image of
the specimen from
reflecting electrons
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Limitations
Can only magnify 10 X
so can’t see the details
of an organism
Lenses are made with
glass; as the lens gets
thicker, the image
becomes blurred.
Specimens with many
layers cannot be
examined
Can only view dead
cells (because you
must make thin
sections of the cell)
Only the outside of the
specimen can be seen
Cannot magnify as
much as TEM
2. Give one advantage of a scanning electron microscope over a transmission
electron microscope. The scanning electron produces a 3D image from
the reflection of electrons off a specimen; therefore, the thickness of the
specimen does not matter (as it did in the transmission e- microscope).
3. Describe the differences in appearance of algae cells when viewed with each of
the different types of microscopes. As you go from the single-lens
microscope to the transmission electron microscope, more detail of
organelles can be seen. The scanning electron microscope can give a 3D
image of the algae, instead of a 2D, flat image.
4. Which microscope would you recommend for viewing each of the following?
Give reasons for your choice.
a) the detailed structure of a cell’s nucleus: If you wanted to keep
the specimen alive, I would use a compound light
microscope, but for the most detail, then the transmission
electron microscope (it’s magnification is 2,000,000X).
b) the outside of a single cell: I would use the scanning electron
microscope to get a 3D image of a single cell and it wouldn’t
matter what thickness the specimen was.
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Section 1.6 – Parts of a Cell Seen with an Electron Microscope
1. Define organelles: Tiny structures within a cell. The parts of a cell that
each of specific functions.
2. What contains the organelles of the cell? Cytoplasm
3. Which organelle is generally the largest of the cytoplasmic organelles?
Mitochondria
4. Complete the following chart on organelles found in both plant and animal cells
when using a transmission electron microscope.
Cell Structures
Mitochondria

Ribosomes

Very small (fuzzy dots
when use TEM
Endoplasmic
Reticulum

Series of folded
membranes
“Rough” ER – where
ribosomes attach
“Smooth” – no
ribosomes attached
Looks like stack of
flattened balloons

Contain special proteins
that breakdown larger
molecules into many
smaller molecules (which
can be reused)
Formed by the Golgi
apparatus
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Golgi
Apparatus
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Lysosomes
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Description
Circular or rod-shaped
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Function
Energy production
“Power plants”
Produce proteins
Proteins needed for cell growth,
repair, and reproduction
Carry materials through
cytoplasm
SER – fats (lipids) produced
here
Stores proteins; puts into
packages called vesicles to
carry to outside of cell
Destroy harmful substances
and invading bacteria
Break large molecules into
small molecules which can then
be reused as building blocks
5. What is the singular word for mitochondria? mitochondrion
6. Write the word equation for cellular respiration in the box below. Where is the
energy produced using cellular respiration used? In almost every other function
of the cell
Sugar (carbohydrates) + oxygen  Carbon dioxide + water + energy
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7. What is the difference between “rough” endoplasmic reticulum and “smooth”
endoplasmic reticulum? RER has ribosomes attached to it, while SER does
not.
8. Cells lining the stomach release enzymes that aid digestion. Digestive enzymes are
protein molecules. Explain why many Golgi apparatuses are found in stomach cells.
The Golgi apparatus stores proteins; therefore, when digestive enzymes
are being made, they need protein. Digestion occurs in the stomach so it
makes sense for proteins to be stored there.
Section 1.7 – Cells in Their Environment
1. What is the difference between the words permeable and impermeable?
Permeable means to allow all materials in and out and impermeable
means that no materials enter or leave.
2. Why are cells membranes called selectively permeable? What is another name
for selectively permeable? Cell membranes allow certain materials to enter
or leave, but not others. Semi-permeable.
3. Define diffusion: the movement of molecules from an area of high
concentration to an area of lower concentration.
4. Diffusion continues until the concentration of the substance is the same inside
and outside the cell.
5. Draw the movement of oxygen and carbon dioxide into and out of a cell using
the process of diffusion. Use the letter O to represent oxygen and CO2 to
represent carbon dioxide.
Oxygen
Carbon Dioxide
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6. Do you think cells could survive without diffusion? Explain why or why not.
No, cells would not survive because there would be no movement of
nutrients into the cell and no movement of wastes out of the cells.
7. Speculate on what would happen if cell membranes were permeable instead of
selectively permeable. All sorts of molecules could enter the cell, including
molecules that might be harmful to the cells.
8. Describe two situations in your everyday experience where substances are spread
around by diffusion. Smelling perfume; smelling dinner; smelling an air
freshner
Section 1.8 – Osmosis
1. Define osmosis: The diffusion of water. Water will diffuse from an area of
high concentration of water to an area of lower concentration of water.
2. What does “concentration” mean? The amount of particles that are the
same (ie. Perfume molecules/particles in a bottle will have a high
concentration since there are more of them in the bottle then in the air)
The amount of a specified substance in a unit amount of another substance.
3. Define solute and name two common solutes found in cells: Solute is a
substance that is dissolved in another substance. Two common solutes are
salts and sugars
4. Define solvent: The substance that dissolves the solute. Common solvent
is water.
5. Refer to Figure 2 on page 25 to answer the following questions:
a) In Figure 2(a), the small blue circles indicate which molecule, water
or protein? water
b) In Figure 2(a), the concentration of water is greater on which side,
X or Y? X
c) In Figure 2(a), what way will water diffuse and why? Water will
diffuse from X to Y (left to right) because there is a higher
concentration of water molecules in X than in Y.
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6. Refer to Figure 3 on page 26 to answer the following questions:
a) In Figure 3(a), the movement of water into and out of the cell is
balanced. The size and shape of the cell will remain the same.
b) In Figure 3(b), the concentration of solutes outside the cell is less
than inside the cell. Water will move into the cell. The size of the cell
will increase.
c) In Figure 3(c), the concentration of solutes inside the cell is less than
outside the cell. Water will move out of the cell. The size of the cell will
decrease.
7. What determines the direction of water movement into or out of cells? Water
moves from an area of high concentration to an area of low concentration.
8. Explain why animal cells are more likely than plant cells to burst when placed in
distilled water. Plant cells have the added protection of a cell wall, while
animal cells do not; therefore, animal cells may burst if too much water
enters.
9. What happens if too much water leaves a cell? The cell will die (water is
needed for chemical reactions to occur).
10. Describe turgor pressure: pressure created inside a plant cell when water
enters by osmosis. Water fills the vacuoles and cytoplasm, causing them
to swell up and push against the cell wall.
11. How are osmosis and diffusion different? How are they the same? Osmosis and
diffusion are different because osmosis is the movement of water while
diffusion is the movement of molecules. They are the same because the
movement is from high concentration to low concentration.
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