STEM Brine Shrimp Lab- Day 2

Today you are going to design an experiment to test a variable of your choice relating to brine shrimp.

Suggestions for variables  (or come up with your own area) that affect the hatching rate of brine shrimp eggs:
     - Temperature
     - Salinity (salt content) of the water
     - Size of container
     - Type of container
     - Ratio of eggs to water

If you are working with salinity, a heaping spoonful of salt in a liter of spring water will give you a salt concentration of 25 parts per thousand.   You can vary the amount of salt to change the concentration.

In your composition notebook you should already have a this lab titled and a 10 sentence section titled 'Background.'

Working with your group members you job today is to come up with your:

Problem- (Stated as a question)

Hypothesis- (What you are predicting what will happen in your experiment)

Materials- (A list of the materials you will need for your experiment)

Procedure- (A DETAILED NUMBERED list of the steps of your experiment)

On the index card Mrs. Keller provides, write a list of materials your group will need for Thursday.  Be complete and specific as possible. Turn this in to Mrs. Keller. 

STEM Brine Shrimp Lab- Introduction and Research

After Keystone testing is over, we will do our final project of the year, Brine Shrimp.

You may have seen brine shrimp marketed as "Sea Monkeys" or even had some when you were a kid!

Today you will need to do some background research with brine shrimp so that you have a depth of understanding necessary to do your lab work.

Title this section of your composition notebook, "Brine Shrimp Lab."

Underneath the this, title the first section, "Background."   Then visit the following links to learn more about brine shrimp.  Write a 10-sentence paragraph summarizing what you learned about brine shrimp.

Brine Shrimp from Learn Genetics

Brine Shrimp from the Great Salt Lake Ecosystem Project

Brine Shrimp in the Great Salt Lake of Utah

Brine Shrimp from Wikipedia


After you are done with your research, think about who you would like to work with in your group (groups of 3 to 4 are good), and in what area your might like to conduct your research.  You might research one of the following areas (or come up with your own area) that affect the hatching rate of brine shrimp eggs:
     - Temperature
     - Salinity (salt content) of the water
     - Size of container
     - Type of container
     - Ratio of eggs to water

After the Keystones you will come together in your group, formulate a hypothesis, and design and complete an experiment to test your hypothesis.

 

Popcorn Energy Flow STEM Lab

Introduction:

In this lab you will create a model of energy flow through FOUR TROPHIC LEVELS of an ecological system.  You will use popcorn and various containers to represent energy flow through each trophic level. (There are  is NOT just one correct way model this.)  You will need paper and a calculator. You will practice using the metric system and calculating percentages.  You will then design a Google Slides presentation  and conclude the lab by teaching your class about energy flow in ecosystems.

Materials:

·                         One bag of popcorn per group.  All of this popcorn must be included on the bottom of your                    energy pyramid (1st Trophic Level)

·                        A variety of containers to represent trophic levels 

                One large plastic bag

               A piece of manilla tagboard to be used as a scoop/funnel

·                         Electronic balances and triple beam balances to calculate the amount of energy proceeding from one level to the next. (Remember, you need to mass only the energy and not the container you have on the balance, so subtract the mass of the container.)

·                          Broom and dustpan

·                          Chlorox Wipes (the waste energy gets all over the lab tables and leaves a greasy residue)

Directions:

1. Work in groups of about 4.

2. Read the section on page 77 of your textbook titled, "Pyramids of Energy."

3. Obtain 1 bag of popcorn from the Energy Supply area. Be sure to note special information on the bag (i.e. mass or volume).  This information may prove useful when you need to perform calculations. DO NOT THROW THE BAG AWAY!

4. Select containers from the materials at the Trophic Level Building Supply Store. You will use these to build a model of energy flow. 

5. Work to create a model of energy flow using your materials. You will write up your procedure such that another scientist could replicate your model. This means each step needs to be justified and explained thoroughly.

6. Special hint---remember only 10% of energy that enters a system makes it to the next trophic level. You need to be able to quantify the amount of energy that leaves a system as waste and the amount that makes it to the next trophic level. This is where the balance and calculator come in.  Include these calculations in your presentation.

7. When you are satisfied with your model, you will show create a 6 to 7 slide Google Slides presentation showing your procedure and results. Take photos with your phone to use in your presentation.   These photos should document your procedure.  Share your presentation with a few group members and nkeller@penncrest.org.

8. Each group will give their presentation on Friday.  You will explain your model to the class as you click through the presentation. 

9. While you are giving your presentation, include the following information:

               In the model, energy is represented by ____ and trophic levels are represented by ____.

               Describe the steps you used to represent energy flow.

              Identify the  types of organisms found at each level of the Pyramid of Energy

              Explain how you calculated the amount of energy lost between trophic levels.  Show your calculations of the amount of energy you began with, as well as the amount lost at each level and passed on at each level. 

              Explain where the missing energy goes.

              Explain why there are very rarely more than 4 levels in an Energy Pyramid.

              Explain why you think you had to do this lab. 

10. Eat your popcorn or throw it away! 

Adapted from a lab by Dr. A Scott, Athens Academy, Athens, GA

How Does Acid Rain Affect Seed Germination? STEM Lab

Background:  One of the problems created by burning fossil fuels is acid rain.  It affects organisms and ecosystems on many different levels.   How does acid rain affect the germination of seeds?

Germination- the process by which a plant begins to grow from a seed

In this lab you will design your own experiment to determine the effects of acid rain on seed germination.  We will allow the seeds to grow until Tuesday and then collect our data, analyze our results, and draw conclusions.


The following materials are provided, you do not need to use them all. 
- Bean seeds (soaked overnight in water)
- Paper towels
- Ziplock sandwich bags
- Rulers
- "Acid Rain"  (water with vinegar (acetic acid) added to it to change the pH values to 6.0, 5.0, and 4.0)
- Non-acidic Rain (tap water)
- Sharpie
- Dropper
- 10 mL Graduated Cylinder
- Scissors

Hints:
* Wrap your seeds up in a paper towel which has been soaked in a solution to simulate being placed in soil with different acidities.  Place this in a Ziplock bag to keep the moisture inside.
*Label everything clearly.
* Seeds need a good deal of moisture

Think about:
* Controlling your variables (seed number, amount of rain,  amount of paper towels, etc.)
* What you will use as a control group?
* Good scientist like multiple trials, so include more than one bean in your Ziplock bag.
* How much "rain" will you use?
* What technique will you use to wrap up your seeds?
* How will you measure your results?  Number of seed germinated, length of root and/or shoot, etc.


Things to write Friday in your composition notebook:
- Lab Title
- Problem
- Hypothesis
- Materials
- Experiment (be SPECIFIC  here; this should be a list of NUMBERED steps explaining what you did.  Someone should be able to replicate your experiment by following the steps.)
- Set up a Data Table that you will complete on Tuesday.

Plasmolysis in Elodea Plant Cells

Write all answers in your composition notebook.   Title this Lab, "Plasmolysis in Elodea Plant Cells" in your notebook.

Pre-Lab (Title this Pre-Lab in your notebook)

Visit the following sites and read the information about the Plasma (Cell Membrane):

Life Science Connections (the Cell Membrane)

University of South Dakota- Cell-ebration: Cell Membrane

Answer the following questions in your notebook. 


1. What is the major function of a cell membrane?
2. Why did the first site depict the cell membrane as a gate?
3. Name 5 important terms associated with the plasma membrane.
4. How is the structure of the cell membrane related to its function?

Visit the following site and read the information about the Cell Wall.  

The Cell Wall from Molecular Expressions

Answer the questions in your notebook. 

5. What is the major function of the cell wall?
6. Describe the structure of the cell wall and its composition.
7. How is the structure of the cell wall related to its function?



Experiment and Observations (Write this as the next section in your composition notebook.)

IMPORTANT NOTE!!! When asked to record your observations do the following:

• Draw a sketch of a group of Elodea cells under the described condition. 

Identify/label the condition.

• Label the magnification under which the plant cells are being observed (40x or 100x).

• Label the sketches to note the cell structures that you can identify.

• Be sure to note any changes in the color, size, and shape of the cells.

• Make your sketches as accurate as possible.

Part 1- Elodea in Tap Water

1. 1. Prepare a wet mount of an Elodea leaf with tap water. To do this, place a drop of water towards one end of the slide. Using forceps, remove a small leaf from the tip of an Elodea plant and lay it flat in the drop of water. Cover with a cover slip.
   2. Observe the leaf at 40X and record your observations.
   3.  Increase the magnification to 100X, observe, and record your observations.
   
   

Part 2- Elodea in 5% Salt Solution

1. Remove the slide from the stage of the microscope.
2. Place 2 drops of the 5% salt solution on the slide at the left edge of the cover slip.
3. Tear off a small piece of paper towel and place the torn edge on the slide at the right edge of the cover slip. The piece of towel should begin to soak up water, drawing the salt solution under the cover slip as it does so. (See Figure)
   
4. Return the slide to the microscope stage and observe the cells at 40X and 100X.
5. Record your observations.

Part 3- Elodea in 10% Salt Solution

1. Repeat the procedure above with 10% salt solution.
2. Observe the cells at 40X and 100X. Record your observations.

Part 4- Flushing Out the Salt Solution

1. Remove the slide from the stage of the microscope.
2. Place 3-5 drops of tap water on the slide at the cover slip.
3. Draw the water through using a small piece of paper towel.
4. Observe the cells at 40x and 100x. Record your observations.
5. 
   

Remove the slide from the stage, clean it, and the cover slip, and put it away.

Conclusions   (Write this in your composition notebook.)

       1. Why did the cells shrink in the salt solutions?  Use the terms diffusion, concentration, and membrane in your answer. 

     2. Why didn't the salt from the outside just move inside the cell instead of the water moving out of the cell?  Use the term selectively permeable in your answer

     3. What structure did the shrinking of the cell allow you to observe in better detail? 

     4. Why didn't the cell wall shrink and collapse? 

     5. Predict what would happen if we used a 20% salt solution for an additional part of the lab.

     6. In a sentence or two, relate what we did in this lab to the concept of HOMEOSTASIS.





Adapted from an AAAS Lab

STEM Bacterial ID Lab

Visit this link to start the lab:  http://media.hhmi.org/biointeractive/vlabs/bacterial_id/index.html

Answer the questions from the off-white paper in your composition notebook.  Title this section "Bacterial ID Lab."

Sexual vs. Asexual Reproduction Online Activity

Sexual vs. Asexual Reproduction Online Activity from Learn Genetics