Science Buddies: "Ask an Expert"

Hello, I need some help with my project please, I am working on the project, How do Roots grow when the direction of gravity changes, my question is: when I rotated 2 of the Cd. cases up side down the roots when left having up side down in front of me but if I rotated Up right the roots are pointing to the R of Right so I don't know what data I supoust to collect, if the case is up side down they are going to the left but they are pointing to the R so I am confuse, please hell me. thanks. Noah

Hello, I need some help with my project please, I am working on the project, How do Roots grow when the direction of gravity changes, my question is: when I rotated 2 of the Cd. cases up side down the roots when left having up side down in front of me but if I rotated Up right the roots are pointing to the R of Right so I don't know what data I supoust to collect, if the case is up side down they are going to the left but they are pointing to the R so I am confuse, please hell me. thanks. Noah

Hi Noah,

Interesting project idea! It would be nice if you could explain a little bit more about how you've set up the experiment. Are you growing plants in CD cases? I'm guessing that you're trying something similar to this but with CD cases instead of plastic bags: https://www.sciencebuddies.org/science- ... vity.shtml
Maybe uploading a photo of your setup would help. It sounds pretty complicated!

Megan

Hello, thanks for your answer, yes I am following the project guide from your web side, I am working with the CD cases, my confusion is when I rotated the CD. Up side down some root go up but pointing down according to the labeling that I did at the beginning of (UP, DOWN, RIGHT AND LEFT), if the Cd case is up side down and the root go up is pointing down so which information i have to collect??? I did try to send you a picture but for some reason is telling me there is a file error. Hope uou can help me, thanks. Noah

Hi Noah,

I read the guide for the demonstration--How does Gravity Affect Root Growth--and I agree that it could be confusing if you don't read it carefully. The main thing you have to remember is that plant roots ALWAYS grow down in response to gravity--provided they have room to do so.

The independent variable in this experiment is the way the bags, or in your case the CD cases, are placed--vertically or horizontally, and whether or not they are rotated. The dependent variable, the actual data that you collect is the direction that the roots grow relative to the position of the CD case. For example the case that you marked 'V' for vertical will have the roots always growing down towards the 'Down' label because you do not rotate this one.

The 'R' case, however, gets rotated several times according to the directions and you must record the direction of the root growth and the label that it is now growing towards. If you look at the photo in the project guide you can see how the changes in rotation affect the direction of the root growth. The root begins by growing towards the 'Down' label. After you turn the case clockwise 90 degrees, the roots (which always grows in the downward direction) are now pointing towards the 'Right' label. Turn it 90 degrees again and the roots will be growing towards the 'Down' label.

What happened to the roots in the case that you left horizontal? The roots can't go down because the case is in the way but they will grow anyway trying to find a way down.

The other thing that you should note in your results is which way the shoot and leaves are growing. Roots always grow down in response to G while shoots always grow up. So, as you rotated the R case the shoot will change direction along with the root so their growth is always opposite.

I hope this answers your question and clears up the confusion. If not, we're here to help.

Sybee

Hi, this is Noah, thanks so much for your help, it is more clear to me, I understand better now. thanks.

You are most welcome, Noah. If you have any other questions about the experiment or about plant growth please post again.

Sybee