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Cell Types Gizmo Worksheet
University of Northern Iowa
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Name: Date:
Student Exploration: Cell Types
Vocabulary: ATP, bacteria, carbon dioxide (CO 2 ), cell, cellular respiration, compound light microscope, eukaryote, multicellular, muscle cell, neuron, organelle, photosynthesis, prokaryote, protist, red blood cell, root hair cell, tissue, unicellular, white blood cell
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
- How do you know if something is alive? Describe some of the characteristics of living things.
Uses growth energy and development, eats, drinks, reproduces
- Humans, plants and mushrooms are all alive. What do these organisms have in common?
same thing as question number 1
Gizmo Warm-up In the Cell Types Gizmo, you will use a light microscope to compare and contrast different samples. On the LANDSCAPE tab, click on the Elodea leaf. (Turn on Show all samples if you can’t find it.) Switch to the MICROSCOPE tab to observe the sample as it would appear under the microscope. By default, this microscope is using 40x magnification.
- Drag the Coarse focus slider until the sample is focused as well as possible. Then, improve
the focus with the Fine focus slider. What do you see? I see a lot of cells grouped together.
- Select the 400x magnification. If necessary, adjust the fine focus. Now, what do you see? I see one cell and I can also see green things in and on it.
The individual chambers you see are cells, the smallest functional unit of an organism.
Activity A:
Observing cells
Get the Gizmo ready: On the LANDSCAPE tab, click on the woman’s right arm to choose the Human skin sample. Select the MICROSCOPE tab.
Introduction: Complex organisms are made up of smaller units, called cells. Most cells are too small to be seen by the naked eye. Microscopes are used to magnify small objects, so here you will use a compound light microscope to observe the cells of different organisms.
Question: What are similarities and differences between cells from different organisms?
- Match : Read about each microscope part. Match the description to the part on the diagram.
F Stage : Platform where a slide is placed.
A Eye piece : Lens at the top of the microscope that the user looks though. This lens most commonly magnifies a sample by 10x.
C Coarse focus knob : Large knob that moves the stage up and down to focus the sample.
D Fine focus knob : Small knob that moves the stage over a short distance to refine the focus.
E Objective lens : A second lens that further magnifies the sample. Microscopes usually have several objective lenses with different magnifications. The total magnification is the product of the eyepiece magnification and the objective lens magnification.
B Slide : A rectangular piece of glass upon which a sample is mounted for viewing under a microscope.
- Manipulate : With 40x selected, use the Coarse and Fine focus sliders to focus on the sample. Then, choose 400x and focus on the sample using the Fine focus slider.
A. Which focus knob is easier to use at 40x? Coarse 400x? Coarse
B. Turn on Show labels. What structures can you see in human skin cells? Nucleus, Cytoplasm, and membrane C. Turn off Show labels and turn on Show scale bars. The scale bar has a width of 20 micrometers, or 20 μm. (There are 1,000 micrometers in a millimeter.)
Using the scale bar, about how wide is a human skin cell? About 33 um
(Activity A continued on next page) Activity A (continued from previous page)
Question: How do a cell’s specialized structures relate to its function?
- Collect data : Use the microscope to observe the samples listed in the t able below. For each sample, estimate the cell size and check off the organelles that are present. If there is no column for an organelle, list it in the Special structure(s) column.
Sample Estimatedsize (μm) Nucleus membraneCell Cytoplasm structure(s)Special
Human neuron 20 um yes yes yes Axon, dendrite Human skin 20 um yes yes yes axon Human muscle 20 um yes yes yes straiation
Human blood 20 um yes yes yes White and red blood cells
- Observe : Select the human neuron sample Observe: Select the human skin sample. On the MICROSCOPE tab, choose the 400x magnification, focus on the sample, and turn on Show labels. Click on the Nucleus label. If necessary, adjust the Stage sliders to see the full description.
A. What is the function of the nucleus? It controls the cell by allowing it to turn the genes on and off. B. What is the function of the cytoplasm? Holds the organelles in place. C. What is the function of the cell membrane? It’s a layer that surroundes and protects the cell
3.. Focus the cells at 400x. Turn on Show labels.
A. Click on the axon label to read the description. What is its function? It carries signals away from the body. B. What is the function of a dendrite? It’s a extention of a nerve cell that lets implueses to get transmitted to the cell body.
Neurons transmit messages in the form of electrical and chemical signals, through axons and dendrites, from one part of the body to another.
(Activity B continued on next page)
Activity B (continued from previous page)
- Compare : Select to the human muscle sample. Observe the sample at 400x.
A. What do muscle cells have that other cell types do not? striation
B. What is a striation and how does it help muscle cells function? They use chemical energy
- Compare : Select the human blood sample. Observe at 400x. Look u nder Show information on the right-hand side of the Gizmo.
A. What is the function of red blood cells? They carry oxygen to our lungs to the rest of our body. B. What is the function of white blood cells? They protect from getting sick C. What organelle is missing from the red blood cells? nucleus
- Compare : Compare the human and animal samples (human and mo use skin; human and worm neurons; human and fly muscle; human and frog blood).
A. In general, are there any major differences that you can see? Explain.
B. What organelle do frog RBCs have that human RBCs do not? nucleus
Most mammalian red blood cells have no nucleus. This allows the red blood cell to use all of its volume to transport oxygen.
- Extend your thinking : Many types of cells, such as the ones in this activity, li ve together in groups, called tissues. A tissue is a group of similar cells that together carry out a specific function. Describe how the skin cells, neurons, muscle cells, and blood cells you have observed relate to the functions of skin, nerve, muscle, and blood tissue.
You can write your answer on another sheet of paper.
Activity C (continued from previous page)
- Observe : Switch to the Protist sample. Protists are unicellular organisms common in ponds On the MICROSCOPE tab, select the 100x radio button and focus the image.
A. Watch the motion of the protists at 100X and 400X. What structures allow each protist to move?
Amoeba: pseudopodium Euglena : flagellum Paramecium : cillium
B. In the table below, draw the structures that allow the protists to move on their images on the left and describe the structures in the spaces on the right:
Amoeba
it has small dots on them and there circles that are different colours
Euglena It looks like a leaf that has pills in it
Parameciu m It looks like a container with rocks in it
C. Which protist is photosynthetic? How do you know?euglena, only one with
chloroplast.
- Compare: On the LANDSCAPE tab, click on the cow to switch to the E. coli sample. On the MICROSCOPE tab, select 2500x , focus the image and turn on Show labels.
A. Find two structures that help E. coli move and describe them below:
Name: Description:
Name: Description:
B. Do protists (amoeba, Euglena , Paramecium ) use similar structures to move? yes
Explain. They all use either the flagellum or pilus to move around and attach to other cells.
Activity D (continued from previous page)
- Collect data : Using the table below, select the sample on the LAND SCAPE tab. Perform the experiment in the light on the TEST FOR LIFE tab. Turn off the light by clicking on the light switch and perform the experiment again in the dark. Record the results below.
Sample Light - ATP Light Respiration Dark - ATP Dark - Respiration E. coli yes yes yes yes
Fungus yes yes yes yes
Human skin yes yes yes yes
Maple leaf yes no yes yes
Root hair yes yes yes yes
Protists yes yes yes yes
Sand/silt no no no no
- Discuss : Based on the results of the experiment, which samples f rom the table above are
likely to undergo photosynthesis? Maple leafs
How do you know? Light doesn’t pass through
- Analyze : Small particles of silt are about the same size and shap e as a cell.
A. Is silt alive? no
B. How do you know? They don’t have energy or respiration
Cell Types Gizmo Worksheet
Course: Textile Science (TEXDSGN 1002)
University: University of Northern Iowa
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