Learning Targets

• Students will conduct an investigation to determine what other things have cells.

Success Criteria

• I have observed and described yogurt viewed under the microscope.
• I can list several things that have cells.

Questions to Ponder

• Do you think there are cells in other places besides your body and plants?
• If you looked at pond water like Leeuwenhoek did, what do you think you would see?
• Do you think there are cells in your food?
• What do you know about yogurt? What is yogurt made of?

Yogurt Lab

• We will observe and describe yogurt viewed under the microscope.

Materials

• For Each Group
  • (2) slides
  • (1) cover slip
  • (1) plain yogurt sample
  • (1) toothpick (for spreading sample on slide)

Procedures

1. Get the necessary materials for this activity from your teacher.
2. Make sure that your slide and cover slip are clean and that there are no fingerprints on them.
3. Place a drop of yogurt on your slide and spread it into a thin layer using either the eyedropper or a toothpick.
4. Place the edge of the cover slip on the slide, and gently lower it over the yogurt. Be careful not to get fingerprints on the slide.
5. Place the slide on the microscope. Adjust the amount of light coming in through the diaphragm of the microscope. It is sometimes easier to see details of the sample in lower light. Add more light if you are having difficulty seeing the sample.
6. Begin with the lowest power on your microscope and then increase the magnification.
7. Describe what you see when looking at the yogurt under high power.
8. Diagram - Make a diagram for each of the powers of magnification you used to look at the yogurt sample. Be sure to write down what power of magnification you used.

Team Talk

• Based on your observations, do you think what you saw in the yogurt were cells? Why?

Whole Group

• Do you think what you saw were cells, or were they something else?
• Do you think they were living? Why?
• What happens to the bacteria if we eat yogurt? What happens to us?

Learning Targets

• Students will conduct an investigation to determine what other things have cells.

Success Criteria

• I have predicted where bacteria might be found
• I have attempted to collect samples and culture them in a petri dish
• I can list several things that have cells.

Bacteria Culturing Lab

Background

• Bacteria are a fascinating type of microorganism that play a large role in our lives whether we like it or not. Will will be attempting to grow our own sample of bacteria while monitoring how it reproduces in a short amount of time. Throughout the growth process compare your sample with others and get proof that bacteria are very different and truly can be found EVERYWHERE.

Materials

• Petri dish
• agar
• sterile cotton swab
• bacteria

PREDICTION

• Where do you think you can find the most bacteria in the school and why?

PROCEDURE:

1. Cut piece of computer paper into 10 cm by 10 cm square
2. Wipe down scale with slightly wet paper towel
3. Place paper square on scale
4. Zero Scale
5. Measure out .75 grams of agar
6. Gently pour agar into hot water
7. Bring water to a boil
8. Allow water to cool
9. Determine Location where you will collect bacteria sample
10. Label petri dish with name of you and partner
11. Label petri dish with specific location as to where sample will be collected
12. Pour agar solution into petri dish
13. Take a walk to collect sample. (ANY STUDENT ACTING IRRESPONSIBLY WILL TAKE A ZERO ON LAB AND WILL NOT GET TO GROW BACTERIA)
14. Take sterile cotton swab out of container
15. Gently rub cotton swab on surface of where you want to collect bacteria sample
16. BE SURE NOT TO CROSS CONTAMINATE SAMPLE ONCE COLLECTED (don’t touch anything with swab)
17. Return to room
18. Rub cotton swab in zig-zag pattern onto cooled agar in petri dish
19. Close petri dish
20. Flip upside down and place in incubator at 37 degree celsius

ANALYSIS AND CONCLUSION

1. Which location has the most different looking bacteria? Why do you think that it has the most?
2. Based on your evidence, what does bacteria need to grow?
3. Using the graph below, describe the trend in the population of bacteria cells from day 1 to day 13.
4. Using the graph below and your knowledge of living things, explain why the population decreases after day 13.

Pond Water Lab

Learning Targets

• Students will conduct an investigation to determine what other things have cells.

Success Criteria

• I have observed and described pond water viewed under the microscope.
• I can list several things that have cells.

Are There Cells in a Drop of Water?

• Are There Cells in a Drop of Water?

Materials

• For Each Group
  • (1) microscope
  • (1) concavity (well) slide
  • (1) cover slip

Procedures

1. Gather the materials for this activity from your teacher.
2. Make sure your slide and cover slip are clean. Be sure there are no fingerprints on either of them.
3. Your teacher will give you directions for getting a sample of the water for your slide. Place a cover slip over the sample. This will keep water from getting on the lens if you lower the microscope too far.
4. Place the sample on the stage of your microscope. Use the lowest power on your microscope. Be sure to check the amount of light coming into your microscope. Begin with a low level of light. It is harder to see objects if there is too much light coming in.
5. In your notebook, describe what you observe.
   • Make a diagram for each of the powers of magnification you used to look at the water sample. Be sure to write down what power of magnification you used.

Team Talk

1. Did you see cells in the water? How do you know?
2. Compare the cheek cells that you saw in Lesson 1 to what you saw in the yogurt and water.
3. Create a T-chart to help organize your answer. Use the chart to describe how they are Similar and Different.
4. Do you think all of the things you saw were cells? Why?

Whole Group

• How did the amoebae compare to the bacteria in the yogurt?
• Did you see any structures inside the amoebae?
• Is there evidence that amoebae are living things?

Gizmo

Enrolling at ExploreLearning.com

Follow these simple steps to enroll in your teacher’s class:

1. Go to https://www.explorelearning.com
2. Click on the “Enroll in a Class” button in the upper right hand corner of the web page.
3. Type in your teacher’s class code: Click “Continue” and follow the directions on the site to complete your enrollment.
4. Write down your username and password and put this sheet in your class notebook.

Congratulations! Now that you’re enrolled, you can login anytime using just your username and password (no class code required).

Cell Structure Gizmo

Complete the Cell Structure Gizmo and then answer the following in your Science Notebook

1. List all the organelles in Animal Cells and summarize their function. (you may use a diagram as part of your summary)
2. List all the organelles In Plant Cells and summarize their function. (you may use a diagram as part of your summary)
3. What are the similarities and differences between Animal Cells and Plant Cells?