Do you think you could walk around upside down -- with your feet in the air and your head on the ground? It'd be kind of silly, and you'd probably get a few weird looks. Well, what do you think would happen if you turned a plant upside down? In this project, we'll work with upside down plants and take a look at the way roots handle this topsy-turvy experiment.
What happens to roots when you turn a plant upside down?
- Bean seed
- Tennis ball container
- Plastic mesh
- Elastic band
- Potting soil
- Spray bottle
- Thick string
- Watering can
- Large nail
- You need a special type of container to experiment with upside down plants, but don't worry -- you can make it yourself. Have an adult help you carefully make a hole in the top and bottom of an empty tennis ball container.
- Put a string through the top hole of the tennis container and out the bottom hole.
- Tie the ends of the string together.
- Fill the container with soil.
- Fill the spray bottle with water.
- Use the spray bottle to gently dampen the soil in the container.
- Put the bean seed inside the container. Make sure it has about an inch of soil covering it. Try to place the seed next to the plastic container wall so you can see what happens once it starts to grow.
- Set aside your plant experiment in a warm, sunlit space. It'll take a while for the seed to sprout. Keep checking back to see if anything has happened.
- Continue to keep the soil damp over the next couple of days.
- As soon as the seed sprouts and you can see some baby roots beginning to poke down, use an elastic band to secure a mesh lid over the top of the container.
- Think about the way a plant normally grows. The sprouts grow toward the sky, and the roots grow toward the ground. Do you know why this happens?
- What do you think will happen when you turn the plant upside down? Write down your hypothesis, or guess, in the notebook.
- Carefully turn the entire container upside down.
- Put the container back in the warm, sunlit space.
- Continue to use the spray bottle to dampen the soil.
- Watch the roots carefully and record what you see in your notebook.
The roots grew down toward the ground even thought the plant was upside down.
Gravity affects everything on earth. Even when you turn plants upside down, gravity doesn't let up. Roots will turn and twist to grow toward the ground, following gravity's stubborn tug.
What do you think would happen if you tried to trick gravity even more? Try this same experiment, but switch the plant right side up after a few days -- before turning it upside down again a few days after that. Do you think you could fool gravity by switching the plant like this? Why not guess and test it out? That's what real scientists do every day -- it's the best way to experiment and see if our guesses about the world around us are correct.