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ANSWERS
Ws 1.3 Plant and Animal Cells
p. 10
1)
Summarize paragraph 1 p. 10
Many cells share common organelles.
2)
Describe 3 things that are easy to do with a microscope.
Can tell apart plant cells from animal cells; which animal cell came from which animal; what the cell does and in what part
it is found.
3)
Define nucleus
Control center (directs all the cell's activities)
4)
What is the nucleus surrounded by?
Nuclear membrane
5)
Define eukaryotic cell.
Cells with a nuclear membrane surrounding the nucleus
6)
Give an example of a 1 celled organism.
Bacteria
7)
Define prokaryotic cell.
Cells without a nuclear membrane surrounding the nucleus
8)
Where are chromosomes located?
Inside the nucleus
9)
What do chromosomes contain?
Deoxyribose Acid
10)
Give 2 functions of the chromosomes.
It holds the construction plans for all the pieces of the cell. It duplicates the genetic information and is then passed on to
off-springs
11)
What is the function of the cell membrane?
Regulates what may enter into the cell and out of the cell
12)
What is it made of?
It consists of a double layer of fat molecules
13)
Define cytoplasm.
A watery fluid that contains organelles inside the cell membrane, and outside of the nucleus
14)
Give 2 functions of the cytoplasm.
Many chemical reactions take place. It also allows materials to be transported quickly between the organelles
15)
Give 2 functions of a vacuole.
Stores water and nutrients; stores and moves waste and excess water out of cell
16)
Fg 1. List the parts of an animal cell that can be seen with a light microscope.
Nucleus; Nuclear Membrane; Chromosomes; Cell Membrane; Cytoplasm; Vacuole
17)
Fg 2. List the 2 structures and state their purpose.
Cilia: tiny hairs that work together to move the cell
Flagellum: one long hair that moves the cell
18)
What is the difference between the cilia and flagellum?
Cilia contain many tiny hairs while a flagellum contains only one long hair.
19)
Are plant cells the same as animal cells?
No, plant cells have: cell wall; chloroplast; a larger vacuole
20)
What is the main difference between a plant and animal vacuole?
Plant vacuoles are much larger than a vacuole in an animal cell.
21)
Fg. 3. List the plant structures that can be seen with a light microscope.
Nucleus; Chromosomes; Cell Membrane; Cytoplasm; Vacuoles; Cell Wall; Chloroplast
22)
What is the function of the cell wall?
Protects and keeps the plant erect.
23)
How are cell walls different?
Some have a single cell wall while others have two for extra support and strength.
24)
What can pass through the cell walls?
Gases, water and some minerals
25)
Define chloroplast.
Chloroplasts are food factories of the plant cell.
26)
What molecule do they contain?
Pigments called chlorophyll
27)
Describe how food is made using the molecule chlorophyll.
Chloroplast creates chlorophyll which allows the plant cells to make their own food using sunlight, carbon dioxide, and
water.
28)
What can animals not do?
Not able to produce their own food.
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Ws 1-5
Technological Advances of the Microscope p. 17
Summarize paragraph 1.
Powerful microscopes allow biologists to see more detail and develop a deeper understanding of the functions of the cells
Who and when was the microscope invented?
In the 1660's by Anton van Leeuwenhoek
Fg 1a. shows?
Leeuwenhoek's microscope
The first microscopes had what magnification?
10 or more times
What does X mean?
Times an object is magnified
Fg 1b. shows?
Single celled plant Algae cellsmagnified by 10X
What was wrong with a single lens?
Not enough details could be seen to understand how cells work
How is the magnification of a 2 lens microscope calculated?
Example: 10X by the first lens and 10X by second lens = 100X
ocular x objective lenses
What is a major problem with microscopes that use glass lenses?
There is a limit: Thicker lenses are needed to magnify the image, but the thicker the lens the more blurry the image
becomes.
What is the maximum magnification of a light microscope?
2000X
Fg 2a shows?
Light microscope
Fg 2b shows?
Algae cells seen under light microscope
What is the maximum magnification of a transmission electron microscope?
2 000 000X
How is this microscope different from a light microscope?
Uses beams of electrons, not light that pass through the specimen of cells or tissues
Why must the specimens be cut into very thin slices?
Electrons are easily deflected or absorbed by thick specimens
The second major limitation to this type of microscope is….
Preparing cells for viewing kills them
Fg 4a shows?
Scanning electron microscope
How is the scanning electron microscope different from the transmission electron microscope?
Scanning electron microscope provides a 3-D image of the object. Only the outside of the object can be seen
Fg 4b shows?
Algae cells seen through a scanning electron microscope
What is one major advantage with this microscope?
The thickness of the specimen does not matter, it can be thick.
What is one major limitation with this microscope?
Only the outside of the specimen can be seen. Also cannot magnify as much as the transmission electron microscope.
ANSWER KEY
Ws 1.6
Parts of a Cell Seen with an Electron Microscope p. 19
1. What does the cytoplasm contain?
Tiny structures called organelles
2. Define organelle.
Tiny structures inside the cell
3. Fg.1 shows?
Animal cell
4. What is a mitochondrion often called?
Power plant for cells
5. What is its function?
provide energy for the cell by undergoing cellular respiration
6. Define cellular respiration.
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Mitochondria release energy by combining sugar molecules with oxygen molecules to form carbon dioxide and
water.
Fg. 2 shows?
Mitochondria
How large are ribosomes?
So small they appear as small fuzzy dots
What do ribosomes do?
Produces proteins
What are proteins needed for?
Cell growth, repair and reproduction
What is an endoplasmic reticulum?
Series of folded membranes
What is a rough endoplasmic reticulum?
Ribosomes are attached to the E.R.
What is a smooth endoplasmic reticulum?
No ribosomes attached
Give the function of the smooth endoplasmic reticulum.
Is the structure where lipids are made
What is the common function of both the smooth and rough endoplasmic reticulum?
Carry materials through the cytoplasm
Fg3a shows?
Rough ER
Fg 3b shows?
Smooth ER
What does the Golgi apparatus look like?
Stacks of flattened balloons
What is this organelles main function?
Stores proteins and puts them into packages
Define vesicle.
Packages / bags that carry protein molecules
Fg 4. What is occurring?
Vesicles containing packages of protein are being released to the outside of the cell
What makes lysosomes?
Special enzymes
What do they do?
Job is to break down large molecules into many smaller molecules that can be used by the cell
Fg 5 shows?
Lysosomes destroying damaged and worn-out cells
Why are lysosomes called the “cell’s recyclers”?
It recycles damaged or worn-out cells
In humans and other animals, what role do lysosomes play?
It destroys harmful substances and invading bacteria that enter the cell
ANSWER KEY
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Ws 1-7 Cells in Their Environment
p. 22
List 5 reasons why you could not live in a sealed bag.
Need: oxygen, water, and food and can't remove waste such as carbon dioxide and urine
What organelle is similar to a sealed bag?
Cell membrane
List 5 things in fg 1.
Protein, cytoplasm, cell surface, pores and lipids (fats)
Explain the terms permeable and impermeable regarding a cell.
Permeable: can pass through
Impermeable: can't pass through
Generalize the relationship between molecule size and the cell membrane.
Cell membranes are semi-permeable. Only certain molecules can go through the pores. Larger molecules need help from
the cell to go through.
Define selectively permeable with regards to a cell.
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Cell membrane allows certain substances to enter and leave the cell
Fg. 3 shows.
Diffusion of ink spreading out in the water
Why do the molecules of ink spread out (KMT)?
The ink molecules are constantly moving and colliding with the other ink molecules and with the water molecules. When
they collide, it bounces off of each other, causing the molecules that are concentrated in one area to spread.
Define diffusion.
Movement of molecules from a greater concentration area to an area of a lower concentration
Why is diffusion important for cells?
One way for substances to move in and out of the cell
Give an example of diffusion inside a cell.
Oxygen is low inside the cell; more oxygen outside the cell. Oxygen molecules diffuse through the cell membrane into the
cell. This is continued until there is an equal amount inside and outside of the cell.
How long does diffusion occur for?
Until the concentration of the substance is the same inside and outside of the cell
Describe the concentration of the waste product carbon dioxide.
Is more concentrated inside the cell than the outside because of cellular respiration occurring in the mitochondria
Cyu 1.7 # 4.
Pores are different sizes to allow only certain substances to enter. The cell wouldn't want anything harmful to enter.
Cyu # 6.
The cell would die because the cell membrane won't allow anything to enter or leave the cell. Waste won't be able to leave,
and the cell won't be able to receive any food, water or oxygen.
Cyu # 7a
Because of diffusion, the lemonade will spread out until it is equally distributed in the pool. Normally, you wouldn't be able
to detect the lemonade because the pool is too large compared to the cup of lemonade.
Cyu # 7b
People would be ingesting the diluted chemicals little by little without knowing it
Cyu # 8
-putting on perfume or cologne
-making tea or coffee
ANSWER KEY Ws 1.8 Osmosis pg25
1. What occurs when celery loses water?
It wilts
2. What is the term used to describe it becoming crisp again?
Osmosis
3. How can water molecules move across a cell membrane?
Diffusion of water through a semi-permeable membrane
4. Define osmosis.
Osmosis is the diffusion of water from an area of greater concentration to an area of lower concentration.
5. What determines the direction that water will flow across a cell membrane?
Area of high concentration to an area of lower concentration
6. Fg. 2, explain how the cell membrane is selectively permeable.
Water molecules can pass through because they are small enough but protein molecules cannot pass through due to
being too large.
7. How can a 100% concentration of water lowered?
When materials are dissolved in pure water
8. Fg 2a. Which side has the greater concentration of water?
Side X
9. Which direction does the water want to move?
Why?
To the right because there is less water molecules there
10. Which side has more protein molecules?
Side Y
11. Which direction does the protein want to move?
Why?
To the left because there is less protein molecules there
12. Why do the protein molecules not switch sides?
Too large to fit through the pores of the membrane
13. Why do the water molecules move sides?
Because of the imbalances in concentration
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14. When will the water molecules stop moving from one side to another?
When the concentration of water on sides X and Y are equal
15. Define solute.
The substance that is dissolved
16. Define solvent.
The substance that dissolves the solute
17. Give an example of each inside cells.
Salts and sugar; water
18. In fg 3a, why is the movement of water into and out of the cell balanced?
It is isotonic. The concentration of solute molecules outside the cell is equal to the concentration of solute molecules
inside the cell.
19. If the solute concentration outside the cell is less than inside the cell, what is the concentration of water outside the
cell compared to inside the cell?
Concentration of water molecules is greater outside the cell than the inside of the cell.
20. Which direction will the water move?
Inside the cell (hypotonic)
21. In fg 3b, why is water moving into the cell?
The concentration of water molecules outside the cell is greater than the concentration inside the cell
22. Why can animal cells burst but not plant cells?
Plant cells have cell walls to protect it from bursting
23. In fg 3c, why is water moving out of the cell?
The solute outside the cell is greater than that found inside the cell.
24. What will happen to this cell?
Cell will shrivel up
25. What happens if the concentration of water is greater outside the cell compared to inside the cell?
Water will move into the cell
26. Fg. 4, why is the produce sprayed with water?
To keep it from wilting
27. Define turgor pressure.
The pressure created inside a plant cell when water molecules enter the cell by osmosis; the water fills the vacuoles
and cytoplasm, causing them to swell up and push against the cell wall.
28. What does turgor pressure do for a plant?
Supports the plant, causing their leave and stems to stay rigid
29. Fg 5, explain.
When plant cells lose their turgor pressure, the plant begins to wilt.
30. Why does the grass salted in the winter wilt in the spring?
The concentration of salt outside is much higher than the concentration of salt in the cell. Water will leave the cell
by osmosis,causing the grass to wilt.
31. Why do plants wilt?
Water creates a turgor pressure, keeping the plant from wilting
Section 1.3: Plant and Animal Cells
Structure
Nucleus
Chromosomes
Cell Membrane
Function
-control center
-directs cell activities
-found inside the nucleus
-contains DNA or genetic info, which holds the construction plans
for all the pieces of the cell
-consists of a double layer of fat molecules
-hold the contents of the cell in place
-acts like a gatekeeper, controlling the movement of materials like
nutrients and water in and out of the cell
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Plant Cell
Animal Cell
yes
yes
yes
yes
yes
yes
Cytoplasm
-a watery fluid that contains everything inside the cell membrane
and outside the nucleus
-where chemical reactions occur
-allows material to be transported quickly between the structures in
the cell
-store waste until they can be disposed of
Vacuole
Cell Wall
Chloroplast
yes
yes
-filled with fluid
-stores water and nutrients such as sugar and minerals
yes
yes
-protects and supports the plant cell
-some cells may have 2 cell walls
-have large pores for materials to pass through
yes
-are food factories of the plant cell
-contains many green chemical called chlorophyll
-chlorophyll allows plant cells to make their own food, using
sunlight, carbon dioxide and water
Flagellum
Cilia
yes
-a whip-like tail
-helps cell to move
-NOT found in all cell
yes (some)
-tiny hair-like structure
-helps cell to move or move the fluid surrounding the cell
-NOT found in all cell
yes (some)
Section 1.6: Part of a Cell Seen with an Electron Microscope (pg.19-21)
Structure
Function
Description
Mitochondria
-provide cell with energy through a
process called cellular respiration
-circular rod shaped organelles
-referred to as power plant
Ribosomes
-produce proteins needed for growth,
repair and reproduction
-use info from nucleus and molecules
from the cytoplasm to produce proteins
-very small organelles
-appear as small fuzzy dots even viewed
with a transmission electron microscope
Endoplasmic Reticulum
-produce fat and proteins
-rough ER produces proteins
-smooth ER produces fat
-carry materials through the cytoplasm
-stores proteins and puts them into
packages called vesicles
-proteins in the vesicles vary, depending
on their function
-a series of olded membranes
-two types: rough has ribosomes
embedded while smooth has no
ribosomes attached
-looks like a stack of flattened balloons
-patrol and clean the cytoplasm
-contain special proteins that used to
break down large molecules into smaller
molecules to be used or reused by the cell
-in humans and animals, lysoosomes play
an important role in destroying harmful
substances and invading bacteria that
enter the cell
-round structure
-formed by Golgi Apparatus
-contain special proteins
Golgi Apparatus
Lysosomes
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CHAPTER 1
CYU 1.1 p.6
1. No, volcanoes are not living things. Although they appear to possess some of the characteristics of living things,
such as growth and breathing out waste gases, they do not possess all the characteristics. For example, volcanoes
are not made of cells.
2. Many answers are possible. A sample answer is provided below.
Characteristic of living things
Non-living things
Living things require energy.
Light bulbs require electricity to work.
Living things respond to the environment.
The wind moves clothes on a clothesline.
Living things reproduce, grow, and repair
A volcano appears to grow.
themselves.
Living things have a lifespan.
Rocks erode and seem to disappear.
Living things produce wastes.
Wastes are produced during the extraction of gold
from ore.
Living things are composed of cells.
Only living things have cells.
3. A living thing is composed of a cell or a number of cells, it requires energy, it responds to environmental stimuli, it
can reproduce, it produces wastes, and it has a finite lifespan. Non-living things may have one or more of these
characteristics. Something is not considered to be a living thing, however, unless it shows all the characteristics.
4. (a) The plant responds to an environmental stimulus, the light.
(b) Living things produce offspring like themselves. Eventually, the tadpole matures into a frog. Also, living things have
a lifespan. The tadpole is one of the life stages of the frog.
(c) Living things produce wastes. Carbon dioxide is a waste that is expelled from the body.
(d) Living things require energy. The seed provides chemical energy for the blue jay.
(e) Living things produce offspring like themselves.
CYU 1.3 p.13HECK YOUR UNDERSTANDING—SUGGESTED ANSWERS
1.
Structure
Function
nucleus
is control centre of cell; directs cell activities
Animal cell
Plant cell
✓
✓
chromosome
contains genetic material
✓
✓
cell membrane
controls movement of materials into and out of cell
✓
✓
cytoplasm
✓
✓
vacuole
allows materials to be transported between cell structures; stores
wastes before disposal
stores water and nutrients
✓
✓
cell wall
protects and supports a plant cell
✓
chloroplast
produces food using light from the Sun
✓
flagellum
allows movement
✓
cilia
cilia allows movement of liquid or other substances around the cell
✓
2.
Similarities between plant and animal cell structures:
• Both plant and animal cells have a cell membrane.
• Both have a nucleus that contains chromosomes.
• Both contain cytoplasm.
• Both contain organelles.
Differences between plant and animal cell structures:
• Plants contain chloroplasts.
• Plants have a cell wall.
• The vacuole is proportionately larger in plant cells.
• Some animal cells have cilia or a flagellum.
3. The genetic material is found in the chromosomes of the nucleus.
4. Accept a wide variety of conclusions, such as the following:
• The cell has mutated.
• The cell is dividing.
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• This type of cell has two nuclei. (Some cells, such as cardiac muscle cells and moulds, are multinucleated.)
5. The cell would not be able to receive any nutrients and would not be able to eliminate wastes. The cell would die.
6. The cells lining the trachea (windpipe) might have cilia. Cilia would prevent dust and debris from entering the lungs and
clogging the alveoli (small sacs), where oxygen is absorbed.
CYU 1.5 p. 18
1. Two lenses permit greater magnification without reducing clarity. Remind students that thicker lenses distort light more
than thinner lenses. By using two lenses, magnification is increased by multiplying the ocular lens by the object lens.
2. Living objects can be viewed using the scanning electron microscope. This microscope has a wider field of view, and
objects do not have to be encased in plastic.
3. A single-lens microscope shows the arrangement of the cells. A light microscope shows some internal structures of the
algae cells. A transmission electron microscope shows the internal structures in greater detail. A scanning electron
microscope shows the three-dimensional structure of the algae cells.
4. Students’ answers may vary. Examples are provided.
(a) Transmission electron microscope—the nucleus is small, and a TEM provides the greatest magnification.
(b) Light microscope—slide preparation is quick and easy, and does not kill the cell.
CYU 1.6 p.21
1. Organelles are specialized structures that are found in the cytoplasm of a cell.
2. Students’ concept maps will vary. Accept all connections that students can reasonably explain. Check that students have
included most of the following terms: cell membrane, cell wall, control, chloroplasts, cytoplasm, endoplasmic reticulum,
energy, food production, Golgi apparatus, lysosomes, material storage, material transport, mitochondria, nuclear membrane,
nucleus, protein manufacturing, protein storage, protection, ribosomes, recycling, rough, surrounds, vacuole.
3. No energy would be available to the cell. Any cell function that requires energy would be impaired. The cell would die.
4. Stomach cells make protein. You would expect cells that secrete enzymes (proteins) to have many Golgi apparatuses,
because protein is stored inside the Golgi apparatus.
CYU 1.7 p.24
1. Diffusion can be explained as the movement of molecules from an area of higher concentration to an area of lower
concentration.
2. Impermeable materials do not allow any substances through. Selectively permeable membranes allow some substances
through, but not others. Permeable membranes allow all substances in contact with them to move through.
3. Cells have a selectively permeable membrane. The cell membrane permits some substances to enter, but keeps other
substances out.
4. Pores of different sizes allow different-sized molecules through the membrane.
Smaller molecules move through smaller pores.
5. Cells could not survive without diffusion because diffusion allows nutrients to enter the cell and waste materials to leave
the cell—both essential processes for keeping cells alive.
6. If a cell membrane were permeable instead of selectively permeable, then all sorts of molecules could enter the cell,
including molecules of substances that might be harmful to the cell.
7. (a) When a glass of lemonade is spilled in a swimming pool, the molecules of lemonade gradually diffuse throughout the
pool. The concentration of lemonade molecules in the pool is so low that you would not be able to detect the lemonade.
(b) If poisonous chemicals were dumped into a lake from which a town draws its water supply, the chemicals would spread
throughout the lake by diffusion and by wind and currents mixing the water. Eventually these chemicals would make their way
into the homes of the town through the town’s water supply system. This might pose a health risk, depending on the amount
(concentration) of the poisonous chemicals in the lake.
8. Two situations where substances are spread around by diffusion are the aroma of cooking or baking at home and smoke
or pollution in the atmosphere (also spread by wind or air currents).
CYU 1.8 p.28
1. Osmosis is the movement of water through a selectively permeable membrane. Diffusion involves the movement of solutes
and does not require a selectively permeable membrane.
2. Water moves from an area of high concentration to an area of low concentration.
3. The cell wall prevents a plant cell from bursting when it is full of water.
4. Plant cells have a supportive structure, the cell wall, but animal cells do not.
5. Turgor pressure is the water pressure exerted on a cell wall.
6. The higher concentration on the outside causes water to move into the plant cells, increasing turgor pressure and thereby
making the plant firmer.
CHAPTER 1 REVIEW ANSWERS p.38
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1. The two main ideas in the cell theory are that all things are composed of one or more cells and that all cells arise only from
cells that already exist.
2. No, large animals do not necessarily have larger cells than small animals. Large animals do have more cells than small
animals, however. Most animals are multicellular; their cells are specialized to perform specific functions.
3. Students’ diagrams should show that the plant cell has shrunk, and the cell membrane has pulled away from the cell wall.
The animal cell will also shrink, but there is no cell wall. The cell appears to shrivel
because water is lost from the cytoplasm.
4. (a) T
(b) F: The light microscope allows scientists to see cells.
(c) F: It is easy to tell animal cells from plant cells, because all plant cells have a cell
wall and many plant cells have chloroplasts.
(d) F: All plant cells are surrounded by a cell wall.
(e) T (f) T
(g) F: Diffusion occurs when molecules move from an area of high
concentration to an area of low concentration.
(h) T
5. Water enters the red blood cell by osmosis. The cell bursts when too much water has entered it.
6. (a) animal
(b) plant
(c) plant
(d) plant
(e) animal
(f) animal
7. The cell membrane must be permeable to sugar. It takes time for the sugar concentration to reach equilibrium (equal
concentration inside and outside the cell). The cell uses sugar.
8. In hemodialysis, the patient’s bloodstream is connected to a machine. The blood is circulated through the machine, and
wastes diffuse out of the blood. In peritoneal dialysis, 2 L of dialysis solution is poured inside the patient’s abdominal cavity,
and wastes diffuse out of the cells of the cavity membranes into the solution. After a while, the solution with the wastes is
drained from the abdominal cavity. Hemodialysis may be more efficient because the wastes are removed directly from the
blood. The patient has to go to a hospital or clinic, however, and be connected to the machine for 3 or 4 h, two or three times
a week. Peritoneal dialysis can be done at home, but it has to be done daily. As peritoneal dialysis is occurring, the patient
can continue with less strenuous activities.
9. To keep the organism within the field of view, the slide should be moved toward D.
10. (a) If athletes drink pure water after exercise, their red blood cells swell because the pure water creates a solution in
which the concentration of solute molecules outside the cells is less than the concentration of solute molecules inside the
cells. Water moves into the red blood cells by osmosis, and the red blood cells swell.
(b) Immerse red blood cells in solutions of varying solute concentrations. Observe the cells after a period of time. Those that
do not change in shape (i.e., do not shrink or expand) are in the most suitable concentration of solutes.
11. Students’ answers will vary. For example, a microscope that could see inside cells without killing the cells would benefit
society. Such a microscope could look inside the cells of a living organism without harming the cells or the organism. This
would be helpful for diagnosing diseases such as cancer.
12. Muscles work by contracting. The long thin shape of the cell in diagram C is better suited for contraction.
13. (a) The student was attempting to answer a question such as “How does temperature affect the rate of fluid movement in
plants?”
(b) If fluids are at higher temperatures, then the rate of fluid movement in plants increases.
(c) The independent variable is the temperature of the fluid. The dependent variable is the rate of fluid movement.
(d) The rates of diffusion are indicated by the rates at which the dye moves up the celery stalks.
(e) The celery stalk in the 40 ºC solution would have the greatest movement of dye. Molecules move faster at higher
temperatures.
(f) Errors could be made in the measurement of the distance the dye moves. The experimental design could be improved by
having celery stalks that are the same size and the same health.
14. Scientists would need to consider whether it displays all the characteristics of living things before they could classify it as
an organism.
15. Students’ answers will vary. Students should mention the importance of controlling all variables (other than the
independent variable) that might possibly have an effect on the outcome. This would enable them to draw more valid
conclusions, since these variables would be eliminated as a possible explanation of the results. Students should also mention
the importance of making accurate observations and measurements. As well, students may indicate that repeating an
investigation will produce more accurate or reliable results.
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