HOW%20TO%20TEACH%20A%20LESSON%20ABOUT%20CELLS

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HOW TO TEACH A LESSON ABOUT CELLS

• By Karen Hughes

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Planning

• Develop a description of lesson
• State goals
• Form objectives
• Educational resources
• Reference materials
• Plan activity
• Describe method of learning
• Prepare assessment

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Lesson Plan Information

• Comparing Cells
• Subject Science
• Category Biology
• Grade Level Ninth
• Duration 60 minutes

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Description

• Students will review various cells using a
  microscope and complete questions based on their
  conclusions.

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Objectives

• To examine similarities and differences in the
  structure of plant and animal cells.

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Educational Resources

• Microscopes Droppers
• Pencils Salt water
• Prepared slides
• Slides and cover slips
• Tooth picks
• Tweezers
• Dishes
• Water

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Reference Materials

• Pictures of cells to be viewed
• Websites

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Activity Plan

• Prep 1. Make sure that microscopes are plugged
  in and set at wide field power (4x objective).
  The shortest of the objective lenses.

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Activity Plan

• Prep 2. Start by obtaining one of the slides.
  You can start with any slide you wish. Follow
  these steps for prepared slides- Frog blood,
  dicot, Amoeba, and Volvox.

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Observation of Prepared Slides

• Step 1. Obtain one of the prepared slides. Make
  sure the slide and lenses are clean.
• Step 2. Focus on cells under wide field power
  using the large, coarse focus knob.
• Step 3. Switch the objective to low power (10x)
  and adjust the same way.

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• Step 4. Finally, have the teacher switch the
  objective to high power (40x) lens.
• Step 5. Adjust using small, fine focus knob
  only. Note adjust light intensity.
• Step 6. Answer questions for each of the cells
  based on your observations and then sketch what
  you see on each slide. See attached sheets.

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• Step 7. Repeat steps 1-6 until you have looked at
  all slides.
• Step 8. Return prepared slides to supply area.
• Step 9. Reset objective lens to lowest power.

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Elodea Leaf and Human Cheek Cells

• Follow these steps for wet mount slides- Elodea
  leaf and Human cheek cell.
• Step 1. Obtain and clean a blank glass slide and
  cover slip.
• Step 2. Obtain a small sample of wither Elodea or
  cheek cells. Elodea leaf- Tear small piece using
  tweezers. Cheek cells- With a tooth pick, gently
  scrape some cells from the inside of your mouth.

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• Step 3. Place a drop of water onto your slide and
  add sample.
• Step 4. Cover the sample with your cover slip.
• Step 5. Focus on cells under wide field power
  using the large, coarse focus knob.

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• Step 6. Switch the objective to low power (10x)
  and adjust the same way.
• Step 7. Finally, have the teacher switch the
  objective to high power (40x) lens.
• Step 8. Adjust using small fine focus only. Note
  adjust light intensity.
• Step 9. Answer questions for each of the cells
  based on your observations and sketch what you
  see on each slide.

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• Step 10. Go to step 1 until you have looked at
  all slides.
• Step 11. Place a drop of salt water solution on
  elodea leaf and note changes. Draw a picture.
• Step 12. Rinse and clean each slide and cover
  slip and return to supply area.
• Step 13. Reset objective lens to lowest power.

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Method of Learning

• Scientific method

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Assessment Questions

• What are some visible differences between the
  cheek and elodea cells? Note structural
  differences.
• When salt water was added to the Elodea what
  changes did you notice in the cell?

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• When looking at elodea under high power what did
  you notice about the boundary between the cell
  membrane and the cell? Once you noted your
  observations then read in your text to further
  explain your answer.
• Compare and contrast the Volvox with the Elodea.

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Websites

• http//waynesword.palomar.edu/lmexer1.htmelodea
• http//www.scarsdaleschools.k12.ny.us/hs/sci1e/fro
  g.html
• http//homemanhattan.edu/frances.carillo/plants/a
  natomy/dicota.html
• http//www.microscopy-uk.org.uk/mag/indexmag.html?
  http//www.microscopy-uk.org.uk/mag/artsep01/amoep
  a.html
• http//dept.kent.edu/projects/cell/f99/if99.htm