Download Cell structure and function File

While doing this assignment have the “Intro to Cells” assignment as a reference
(particularly the labeled key that tells you the function of different organelles).
To answer these questions use your brain first, then discuss with your lab
partners. As a last resort use the internet to find clues.
Cell structure and function:
Cells will look differently and behave differently based on the jobs that they do in your
body. We would say that the cell’s structure (what it looks like) is determined by it’s
function (the job they do). Although almost every cell in your body has the basic
organelles you just studied, they would have them in different amounts depending on
the function of the cell.
Blood Cells:
Figure 1: Diagram showing the structures of the varying types of blood cells found in blood tissue
Blood cells take on several different forms. Red blood cells are responsible for
absorbing oxygen in the lungs and delivering oxygen to body tissues while phagocytic
white blood cells are responsible for absorbing and destroying invaders (like bacteria)
in your body.
1. Take a look at red blood cells under the microscope here:
http://www.exploratorium.edu/imaging_station/gal_media/human/humanredbc/humanredbc_
800.jpg
2. Take a look at red and white blood cells together under the microscope and note their different
shapes and movement:
http://www.exploratorium.edu/imaging_station/hbvideo.php?Asset=Human%20white%20bloo
d%20cells&Width=720&Height=530&Location=gal_media/human/neutrophil/neutrophil_hb.swf
3. Take a look at a white blood cell absorbing and destroying a bacteria here:
0cell%20%20phagocytosis&Width=720&Height=530&Location=gal_media/human/phagocytosis/phagocy
tosis_hb.swf
Questions:
1.
What is the function of red blood cells?
2. What is the function of white blood cells?
3. Compare the shape of red blood cells to white blood cells. How are their shapes different?
a. Why do you think red blood cells have the shape that they do?
4. Red blood cells do not have a nucleus; any guess as to why red blood cells do not have a
nucleus?
a. Are red blood cells capable of reproduction? Explain.
5. Compare the movement of red blood cells to white blood cells. Which one seems more active?
a. Which blood cell do you think would have more mitochondria? Explain your reasoning.
6. Which blood cell would have more lysosomes? Explain your reasoning.
Comparing a nerve cell to a sperm cell
Nerve cells and sperm cells have very different functions. A nerve cell (or neuron)
is responsible for transmitting signals through your body. These signals relay
information to and from the brain. The brain collects information from your body
through signals that run through your neurons then directs your body’s actions
through similar signals that run through neurons. Neurons connect every part of
your body to the brain and spinal cord like power lines connect houses, businesses
and cities to power stations.
7.
Figure 2: A nerve cell (or neuron) with internal organelles revealed
Figure 3: Nerve cells with basic structures labeled. This image also displays nerve cells alignment with each other.
A sperm cell’s sole job is to deliver it’s DNA to an egg cell during fertilization to
create a new human. A sperm competes with millions of other sperm. T he first
sperm to the egg is the only sperm that fertilizes it. The fastest sperm is the one
that get’s to pass it’s DNA on to the next generation.
Figure 4: Sperm cell with basic structures labeled
8. What do you think the function of the tail is in the sperm cell?
9. What do you think the function of the long extension (the axon) is in the nerve cell?
10. Do you think the sperm cell or nerve cell has more mitochondria? Why?
11. Google the function of dendrites that are found on nerve cells. Why do you think a nerve cell
has so many of these structures?
Comparing Plant Cells
Plants also have specialized cells that perform specific jobs in the plant. The root
cells are found in the roots of plants. Those cells found on the outer surface of
the root have an unusual shape with an extension called a root hair. The funct ion
of the guard cells found in the leaves of a plant is to control the opening and
closing of the stomata. Stomata are the tiny holes where water is transpired,
oxygen exits the plant and carbon dioxide enters the plant. When the guard cell’s
vacuole is swollen with water if forces the cell into a curved shape that opens the
stomata. When the guard cell’s vacuole is drained of water, the cells shrink
closing the stomata.
Figure 6: Gaurd cells with internal structures labelled in
both a open and closed position.
Figure 5: Structure of a root with an inset of a root cell
with root hair.
12. What do you think the function of the root hair is in the root cell?
13. Why do you think the root hair has the shape that it does?
14. Do you think a root cell has chloroplasts? Why or why not?
15. What’s the purpose of having the guard cells seal the stoma closed when their vacuoles start
losing water? (Think about the outside environment and the overall health of the plant).
16. Why do you think the cell wall on the interior of the guard cell (the wall that is lining the
stomata) is thicker than the cell wall on the outside of the stomata? (See figure 6)