slime mold

[vice]

I really want to do slime mold maze test. My teacher shot down the idea because of no control. Would setting it up the same with out using food be the control? I would have the maze in place?Would I need to add distilled water to the two places where I would have food to show it was moving to food and not just moisture? Could I have just a straight path of the same length of the other two paths to show it would move straight to the food? Also, I have to have graphs for data. I was going to run 8 or 9 at same time with same conditions (temp, etc.) Have number that went to easiest over total? Are they too small to be able to count the parts that go to each food? Could that be a second graph? Or would I need to measure the size of the blob? If there are more is it darker? can I judge by color? HELP!

[sunmoonstars]

Hi,
This is a very interesting project. I read through the outline here - https://www.sciencebuddies.org/science- ... ?from=Blog

Let's go through the variables (from here https://www.sciencebuddies.org/science- ... bles.shtml):

Independent variable - the variable that is changed by the scientist. This could be two separate runs side by side, one with food and one without. The availability of food is your independent variable.

Dependent variable - this is the variable you will monitor as the reaction to your independent variable. In this case it will be the slime mold's reaction to the availability of food (your independent variable).

Controlled variables - these are other things that could change if you aren't careful - and contribute to your dependent variable's outcome if allowed to become independent variables. in this case, between your two runs (with food and without food), you will want to keep the humidity, maze layout, and agar composition controlled. Can you think of anything else that could add variability to your test if not watched carefully? Perhaps the number of starting slime mold pieces and the size of those pieces? Anything else?

[sunmoonstars]

I need to answer your other questions:

Would setting it up the same with out using food be the control? The availability of food would be your independent variable. You could have two or three groups - with oats for food, without any food, and if you choose to add a third - some object that isn't food, like plastic bits.

I would have the maze in place?Would I need to add distilled water to the two places where I would have food to show it was moving to food and not just moisture? I don't think I would use water in place of food because you wmay affect the humidity. I would just do food or no food (and maybe a non-food).

Could I have just a straight path of the same length of the other two paths to show it would move straight to the food? This would be adding another variable - the layout of the maze.

Also, I have to have graphs for data. I was going to run 8 or 9 at same time with same conditions (temp, etc.) Have number that went to easiest over total? Are they too small to be able to count the parts that go to each food? Could that be a second graph? Or would I need to measure the size of the blob? If there are more is it darker? can I judge by color? HELP! Perhaps just a yes/no answer - ether the slime mold reached the two food sources using the shortest path or not. Or you could chart the length of time it took each of the runs to reach the two food sources.... and since the no-food runs wouldn't reach, they would be graphed as not-reached (n/a)

[vice]

I did the test. I had two controls. One got contaminated, the other took the shortest path to the exit even though it had no food. I guess my explanation for that will be that maybe some food was attached to slime I put in at exit? I put slime at entrance and exit. Since it did that i put slime at entrance and exit again after most had run its course. I figure i can have a second test to show it would have thicker connections between shorter route? After I did this the control had grown out of the maze. The others stayed in the maze. So the control is not completely lost? Also, for graphs what should I show? I kept track of which path it took. Sometimes too much time went by so it had gone both ways? So i can't say which way was first? How do I include that in a graph? Since it did that I added the slime to both entrance and exit to measure thickness. I noted where it was thicker and drew pictures but what would I graph?

[sunmoonstars]

Hi again,

That's great you were able to complete your test. I'm happy to hear you are moving on to your results. Hopefully these answers will help you out, but I do have some questions for you, too.

I did the test. I had two controls. One got contaminated, the other took the shortest path to the exit even though it had no food. I guess my explanation for that will be that maybe some food was attached to slime I put in at exit? There could have been some food left, that would explain why the control slime did that. Otherwise, was the maze big enough for the slime to have to explore?

I put slime at entrance and exit. Since it did that i put slime at entrance and exit again after most had run its course. I figure i can have a second test to show it would have thicker connections between shorter route? After I did this the control had grown out of the maze. The others stayed in the maze. So the control is not completely lost? It seems the control was searching for food and did not find it, so it went off the maze. This could be a control run. What did you want to show using your control? That your slime won't randomly go to the exit (like it did the first time) - because they would mean all your other trials could just be showing a random result.

Also, for graphs what should I show? I kept track of which path it took. Sometimes too much time went by so it had gone both ways? So i can't say which way was first? How do I include that in a graph? If you cannot be sure which was first, you could either "throw those results out", or use their shortest path measurements and ig nore the fact they had 2 paths. Whichever you choose, you'll have to explain why you selected this choice.

Since it did that I added the slime to both entrance and exit to measure thickness. I noted where it was thicker and drew pictures but what would I graph? You could answer yes or no for each slime run - whether or not it made it's way to the food in the shorter ath. Graph the yes vs no. I am not sure what you could graph for thickness - what was the point of measuring the thickness? Each graph should answer a question. What question would be answered if you made another graph?

[vice]

I am drawing a chart. I had 10 plates. 6 showed easiest route. 0 chose other route. 4 I couldn't tell which route came 1st. I was doing a column chart. Vertical axis is number of plates and horizontal is the three routes taken. Name of chart? ? by route taken? Other test showed which route had denser growth. I was going to do pie chart with percentage of plates showing route 1, route 2 or equal preference. Name of chart? Thanks. Vice

[sunmoonstars]

Hi vice,

Perhaps - slime molds prefer the shortest route to food in a maze

And number two - perhaps - colony thickness compared to route length preference