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Activities and Experiments

Lesson 3: Plants

In these experiments, you will use some of the hormones we discussed

earlier to discuss their practical impact on plants. Take a moment to go
back and review this section. You will also grow some plants in your own
greenhouse, and conduct an experiment to see exactly how plants grow.
You will also do some experiments reviewing the process of photosynthesis
we discussed earlier.

Two Bananas are Better than One

Another hormone involved in plants is ethylene. Ethylene is an unusual
hormone because it is a gas. What does this mean? Find out using a fruit
with plenty of ethylene, a ripe banana.

1. Place one green banana in a paper bag.

2. Place another green banana in a paper bag, along with a very ripe
banana.

3. Make daily observations about each banana.

4. What’s causing the differences you see? Hint: Think about ethylene
and how it can travel.

What’s Happening: Ethylene is found in plants throughout their lifetime. In

plants with fruit, ethylene levels increase when the fruit is ready to ripen.
So, a ripe banana produces more ethylene than a non-ripe one. In the bag
with two bananas, the gas travels from the ripe banana to the unripened
one. This causes it to ripen faster than it otherwise would. Changes in
ripening time happen naturally too. In flood or drought conditions, ethylene
will not be produced as greatly, so the plant will not ripen in such an
environment.

Build Your Own Greenhouse

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