Investigation Lab: Growing Plants
Learn
Scientists learn by doing experiments. In this lesson, you will be a scientist! You will grow plants to see what they need.
What Is an Investigation?
An investigation is when we ask a question and try to find the answer. Scientists follow these steps:
- Ask a question - What do you want to find out?
- Make a prediction - What do you think will happen?
- Do the test - Try it and watch carefully!
- Record what you see - Write or draw what happens.
- Share what you learned - Tell others what you found out.
Our Big Question
Today we will investigate: What happens to a plant when it does not get what it needs?
Setting Up Our Investigation
We will grow bean seeds in different conditions:
- Plant A: Gets water, sunlight, and air (everything it needs!)
- Plant B: Gets sunlight and air, but NO water
- Plant C: Gets water and air, but NO sunlight (kept in a dark closet)
Making Predictions
Before we start, we predict what will happen. A prediction is your best guess based on what you already know.
Think about it: Which plant do you think will grow best? Which might not grow at all?
Examples
Example 1: Recording Observations
Maya is watching her plants. Here is how she records what she sees:
| Day | Plant A (all needs met) | Plant B (no water) |
|---|---|---|
| Day 1 | Seed in wet soil | Seed in dry soil |
| Day 5 | Small green sprout! | Nothing yet |
| Day 10 | Tall with 4 leaves | Still nothing |
What Maya learned: The plant with water grew. The plant without water did not grow.
Example 2: Drawing What You See
Scientists often draw pictures of their observations. Look at Carlos's science journal:
Day 7 - My Plant Drawing
Carlos drew Plant A with a stem, two leaves, and roots in the soil. He labeled the parts: stem, leaf, soil, roots.
He also drew Plant C (no light) with a very long, thin stem and tiny pale leaves.
Carlos noticed: The plant in the dark grew tall but looked weak and yellow. The plant with light was shorter but green and strong.
Example 3: Comparing Results
After 2 weeks, the class compared all three plants:
- Plant A: Green, healthy, 6 inches tall with many leaves
- Plant B: Did not sprout - the seed stayed the same
- Plant C: Grew 8 inches tall but was pale yellow and fell over
Conclusion: Plants need BOTH water AND sunlight to be healthy!
Practice
Answer these questions about plant investigations.
1. What is the FIRST step in an investigation?
A) Do the test
B) Ask a question
C) Share what you learned
D) Record what you see
2. What is a prediction?
A) Writing down what you see
B) Your best guess about what will happen
C) The question you want to answer
D) Telling others what you learned
3. Sara's plant has no sunlight. What will probably happen?
A) It will grow big and green
B) It will grow but look pale or yellow
C) It will grow faster than normal
D) Nothing will change
4. Why do scientists write down what they see?
A) Because their teacher said to
B) So they can remember and share what happened
C) Because writing is fun
D) So they can draw pictures
5. Look at this data: Plant A got water and grew 5 inches. Plant B got no water and grew 0 inches. What can you conclude?
A) Water does not help plants
B) Plants need water to grow
C) Both plants grew the same
D) Plant B got too much sun
6. Which is the BEST way to record your plant observations?
A) Just remember them in your head
B) Write or draw what you see each day
C) Only look at the plant once
D) Ask someone else to tell you
7. Emma wants to know if plants need air. She puts one plant under a glass jar with no air holes. What should she do with the other plant?
A) Also put it under a jar
B) Keep it where it can get air
C) Give it extra water
D) Put it in the dark
8. What tool would help you measure how tall your plant grows?
A) A thermometer
B) A ruler
C) A magnifying glass
D) A clock
9. Ben's prediction was that the plant with no water would grow best. His investigation showed the plant with no water did not grow at all. What should Ben do?
A) Change his data to match his prediction
B) Accept that his prediction was wrong and learn from it
C) Not share his results
D) Say the investigation did not work
10. Why is it important to give Plant A everything it needs in our investigation?
A) So we have something to compare the other plants to
B) Because Plant A is our favorite
C) So Plant A will win
D) Because we only care about Plant A
Check Your Understanding
Think about these questions. Discuss with a partner or write your answers.
1. In your own words, what are the steps of an investigation?
2. Why is it important to only change ONE thing (like water or light) at a time in an experiment?
3. If you wanted to find out if plants need soil to grow, how would you set up your investigation?
Next Steps
- Try the plant investigation at home with a grown-up
- Keep a science journal to record your observations
- Continue to the next lesson to learn how to make graphs from your data