The picture you see above is that is a humble slime mold growing in some wood chips beneath the toes of unsuspecting school children playing at a playground. As a science teaching tool, the slime mold is unparalleled in engaging students asking questions, designing experiments and learning how to engage in evidenced-based reasoning and argumentation.
Objectives:
1. Science as discovery. Students will learn to make keen observations, ask questions and build evidenced-based arguments to support their thinking.
2. Discovery - Students learn about a species they may have never heard about and find that it is both simple and complex depending on how you classify it and to what you compare it.
3. Classification - students learn that slime molds are very difficult to classify having qualities that are fungus-like, animal-like, plant-like and protist0list.
Preparation:
1. Order slime mold in the dormant stage from Carolina Biological Supply Company. Here is a link to the specific product.
http://www.carolina.com/slime-molds/physarum-polycephalum-sclerotium-living-box/156190.pr?question=
2. Prepare or order petri dishes filled with NON-NUTRIENT agar. The agar must be non-nutrient to keep down bacteria and mold growth on the agar.
Procedure:
I chose to do a slime mold activity literally the first day of school in the fall. Students come in, we do the typical meet and greet and then students get to work.
1.after placing the students in pairs, I describe a situation of having an unknown substance that we want to learn more about. Each pair receives a small piece of paper with a yellow, dried substance on it. They are instructed not to touch it in order to not contaminate it or themselves.
2. Students draw pictures and write descriptions of their "unknown substance".
3. I demonstrate sterile technique and then students use sterile technique to place the unknown substance on the top of the agar (using forceps), replacing the lid on the petri dish and writing their initials on the side of the dish. (I do not explain the function of the agar until the entire activity is over).
4. Store the dishes in a cool, dark drawer.
5. On the second day of class, students will examine their dishes and find that the unknown substance has spread out on top of the agar. After students have again drawn pictures of their substance and written descriptions of what they see and how it has changed since yesterday, I ask the question "Is the substance alive". I have students discuss this question with their partner and with other students in the class.
6. After their discussions, I have students use sterile technique to add a small piece of oat flake (again - I do not identify this substance) to the top of the agar in their dish.
7. Again, store the dishes in a cool, dark drawer.
8. On the third day of class, students will see that their yellow unknown substance has moved and is now on top of the second item (oat flake) added to the dish.
9. After students make their sketches and write their descriptions, ask again "Is the yellow substance alive?" As a class, have students provide their evidence to support their argument. There is much evidence that the slime mold is alive and students can refer to its stimulation by the wet agar, its movement, the transition to the food source and its growth. Depending on time, teachers can move forward in several possible ways:
A. Reveal that the slime mold is indeed alive. You can share the information from Carolina
Biological Supply or you could should the video clip or article with links given below.
Objectives:
1. Science as discovery. Students will learn to make keen observations, ask questions and build evidenced-based arguments to support their thinking.
2. Discovery - Students learn about a species they may have never heard about and find that it is both simple and complex depending on how you classify it and to what you compare it.
3. Classification - students learn that slime molds are very difficult to classify having qualities that are fungus-like, animal-like, plant-like and protist0list.
Preparation:
1. Order slime mold in the dormant stage from Carolina Biological Supply Company. Here is a link to the specific product.
http://www.carolina.com/slime-molds/physarum-polycephalum-sclerotium-living-box/156190.pr?question=
2. Prepare or order petri dishes filled with NON-NUTRIENT agar. The agar must be non-nutrient to keep down bacteria and mold growth on the agar.
Procedure:
I chose to do a slime mold activity literally the first day of school in the fall. Students come in, we do the typical meet and greet and then students get to work.
1.after placing the students in pairs, I describe a situation of having an unknown substance that we want to learn more about. Each pair receives a small piece of paper with a yellow, dried substance on it. They are instructed not to touch it in order to not contaminate it or themselves.
2. Students draw pictures and write descriptions of their "unknown substance".
3. I demonstrate sterile technique and then students use sterile technique to place the unknown substance on the top of the agar (using forceps), replacing the lid on the petri dish and writing their initials on the side of the dish. (I do not explain the function of the agar until the entire activity is over).
4. Store the dishes in a cool, dark drawer.
5. On the second day of class, students will examine their dishes and find that the unknown substance has spread out on top of the agar. After students have again drawn pictures of their substance and written descriptions of what they see and how it has changed since yesterday, I ask the question "Is the substance alive". I have students discuss this question with their partner and with other students in the class.
6. After their discussions, I have students use sterile technique to add a small piece of oat flake (again - I do not identify this substance) to the top of the agar in their dish.
7. Again, store the dishes in a cool, dark drawer.
8. On the third day of class, students will see that their yellow unknown substance has moved and is now on top of the second item (oat flake) added to the dish.
9. After students make their sketches and write their descriptions, ask again "Is the yellow substance alive?" As a class, have students provide their evidence to support their argument. There is much evidence that the slime mold is alive and students can refer to its stimulation by the wet agar, its movement, the transition to the food source and its growth. Depending on time, teachers can move forward in several possible ways:
A. Reveal that the slime mold is indeed alive. You can share the information from Carolina
Biological Supply or you could should the video clip or article with links given below.
1.
Video – PBS. org
2.
Slime Mold Article – Smithsonian Magazine
http://www.smithsonianmag.com/science-nature/phenom_mar01.html
B. Have students design and carry out simple experiments to test life characteristics of the slime
mold. The living mold can easily be cut, moving a piece of it on its agar to a new agar coated dish.
C. Students can design mazes for their slime molds. They can either cut the agar into different maze
shapes or add different features such as bridges or moats to their agar dish.
10. Lastly, spend a little time on the classification of the slime mold. Explain why they are difficult to
classify and how they are currently classified.
Here is a link to a discussion of their classification:
http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Slime_mold.html
B. Have students design and carry out simple experiments to test life characteristics of the slime
mold. The living mold can easily be cut, moving a piece of it on its agar to a new agar coated dish.
C. Students can design mazes for their slime molds. They can either cut the agar into different maze
shapes or add different features such as bridges or moats to their agar dish.
10. Lastly, spend a little time on the classification of the slime mold. Explain why they are difficult to
classify and how they are currently classified.
Here is a link to a discussion of their classification:
http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Slime_mold.html
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