MSP Science Lesson – 5.3 Cells
GPS Standard:
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.
Essential Question:
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What do all eukaryotic cells have in common?
How do plant and animal cells differ?
What are the functions of the cellular organelles?
Engagement: (Find out what teachers already know)
Venn diagram (compare/contrast)
Plant Cells
Animals Cells
All Cells
Another idea could be to begin a concept map. I like to do this as an engagement activity with students in
groups. As students progress through an activity they add information using sticky notes (“parking lot”).
As a culminating assessment, each group does a final concept map. See addendum to this activity.
Exploration I:
http://www.southerncompany.com/learningpower/pdf/Lifedrops_A%20Pond%20Water%20Study.pdf
Materials (per group):
Microscopes, slides, cover slips, water, dropper, iodine and/or methylene blue stain, onions, Elodea
(available at pet stores, aquarium section), pond water or hay infusion liquid, flat tooth picks, other
assorted samples for viewing or prepared slides that might include some non-living samples like sand, salt
crystals, etc.
Note: For teachers without microscopes, slides 1 – 6 of PPT show may be used.
Directions
Teacher should demonstrate how to make wet mount and dry mount slides. A wet mount slide includes
the following: a slide, a cover slip, a specimen, a drop of stain or water. When preparing a slide, hold the
cover slip at an angle and let it drop onto the slide slowly trapping the specimen between the two pieces
of glass. A piece of onion skin is easy to use in this first activity. Soak onion sections the night before in
water.
Get into groups of 4. Read through the different wet mounts that you need to make and decide
who will prepare each one. Each person in the group will take a turn preparing a wet mount and
sharing it with everyone else in the group. Carefully follow the instructions for each sample.
Everyone in the group will draw what each sample looks like on their own piece of paper and
give a brief description of the unique characteristics that they see in that sample (i.e. color,
movement, size, thickness, etc.). Also, decide as a group, if the specimen is animal or plant.
Elodea Leaf: Prepare a wet mount of an Elodea leaf by tearing a single leaf from the stem and
placing it on a slide with a drop of water and a cover slip. Observe the leave under low and high
power.
Onion epidermis: With tweezers or finger tips, remove the inner surface of a section of an
onion. (It will look very thin, like saran wrap.) Make a wet mount of the onion skin and observe
it under low and high power. Try adding a drop of iodine stain to the slide and re-examine the
cells.
Cheek: Scrape GENTLY the inside of your cheek with the flat end of a toothpick (DO NOT
DRAW BLOOD!) and rub the toothpick onto a slide. Go to a sink and add one drop of
methylene blue to the slide and cover with a cover slip. Caution! Methylene blue stains so don't
get any on you! Using an eyedropper, rinse the excess methylene blue into the sink. You
should see tiny blue specks on the slide. These are your cheek cells. Dry the bottom of the
slide. Examine under low and high power.
Pond Water: Place one drop of pond water on a slide and put a cover slip over it. Turn the light
down on your microscope and search for living organisms. How do you know that what you are
looking at is living?
Cell Comparison Lab
Student Observations
Procedure:
* Draw the cells you see from your microscope field in the circles below.
* Label on the first line whether it is a Plant or an Animal cells.
* Explain what distinguishing characteristic(s) makes them a plant or an animal cell.
Summarize: Describe briefly what was similar about all of the cells you viewed. Describe what was different.
Alike –
Different –
Explanation I: (Interpret the observations)
1. Plant cells have a cell wall, but animal cells do not.
2. Plant cells have chloroplasts, but animal cells do not.
3. Plant cells generally have a more rectangular shape because the cell wall is more rigid. Animal
cells have a round or irregular shape because they do not have a cell wall.
4. Plants cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles,
if any are present.
Animal Cell
Plant Cell
An organelle is a small structure within the cell (organelle literally means 'tiny structure'). Some
examples of cell organelles are the cell wall, cell membrane, and nucleus. The following are the
major functions of organelles:
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barrier between cell and its environment
protection/support
building and repairing of cell parts
transport of materials
storage and release of energy
disposal of waste materials
reproduction (increase in number)
Exploration II – Organelles
Using PowerPoint slides 11 (or go straight to Cells Alive interactive site for comparing plant and animal
cells) and 12 (table of organelles), students can investigate function of cellular organelles and continue
comparison of plant versus animal cells. This can be a whole class activity (1 computer classroom), done
in small groups (several computers), or as an individual activity (computer lab).
Explanation II – http://www.usoe.k12.ut.us/curr/science/sciber00/7th/cells/sciber/orgtable.htm
For completed table of cellular organelles
Extension:
If you’re into technology and microorganisms – A virtual pond dip
http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/ponddip/index.html
If you’d like to set up an in-class investigation of microorganisms:
http://www.bottlebiology.org/
If you’ve already used duckweed in your investigation, here are several activities, most related to ecology,
you might try:
http://www.mobot.org/jwcross/duckweed/education.htm
Everyday Applications
 Beneficial (waste water treatment; oil spill clean-up) and harmful bacteria (infections, disease) –
tie in to standard S5L4
 Genetics – tie in to standard S5L2
 Environmental science applications using a familiar organism http://www.mobot.org/jwcross/duckweed/education.htm
Cross Curriculum Connections
 History/technology:
Students will research historical events leading to the development of the cell theory.
o Research should include contributions made by the following people/scientists -Robert
Hooke, Hans and Zacharias Janssen, Anton van Leeuwenhoek, Matthias Schleiden,
Theodor Schwann, Rudolph Virchow, etc. and dates of their contributions.
2. Students will report on their findings by constructing a timeline showing the chronology of the
1.
Resources
What to do if you don’t have microscopes:
http://comm.nsdl.org/download.php/915/NSDL_WS7_Microscopes.pdf
Everything you need for a cell comparison study:
http://waynesword.palomar.edu/lmexer1a.htm
Cell photographs:
http://www.usoe.k12.ut.us/curr/science/sciber00/7th/cells/sciber/cellphot.htm
Great cell unit:
http://www.usoe.k12.ut.us/curr/science/sciber00/7th/cells/sciber/intro.htm
Cell organelles – table w/ functions:
http://www.usoe.k12.ut.us/curr/science/sciber00/7th/cells/sciber/orgtable.htm
Tons of cell sites:
http://classroom.jc-schools.net/sci-units/cells.htm
Interactive plant and animal cells; illustrations to download
http://www.cellsalive.com/
Cell website with good basic cell facts and slides:
http://library.advanced.org/3564/
Amazing microscopy from England:
http://www.microscopy-uk.org.uk/micropolitan/index.html
Cell facts; quizzes:
http://www.biology4kids.com/files/cell_main.html
Free registration; excellent science resources:
http://www.teachersdomain.org/tdhome.html
Evaluation:
Participants …
 Mini quiz (PPT slides 7 – 10
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http://www.usoe.k12.ut.us/curr/science/sciber00/7th/cells/sciber/intro.htm)
Build a cell (PPT slide 13 (http://www.bioscope.org/taste/builda.htm)
Complete Venn diagram or concept map
Complete compare and contrast chart of organelles
Culminating activity – Cells on the Ceiling
http://www.accessexcellence.org/AE/AEC/AEF/1994/hopkins_cells.html