Plant Growth Variables Lab
Adjust sunlight, water, soil type, and temperature to see how each affects how tall your plant grows after 30 days. Change one variable at a time to run a fair test.
Guided Experiment: Sunlight Investigation
How does the amount of sunlight affect plant height after 30 days? Write a prediction: 'I think a plant with more sunlight will grow... because...'
Write your hypothesis in the Lab Report panel, then click Next.
Controls
Plant on Day 30
Growth Summary
Data Table
(0 rows)| # | Sunlight(h/day) | Water(mL/day) | Soil Type | Temp(°C) | Day | Height(cm) |
|---|
Reference Guide
What Plants Need to Grow
Plants make their own food through photosynthesis, but they need the right ingredients. Too little of one resource limits growth even if all others are perfect.
How Plants Make Food
Plants use sunlight, water, and carbon dioxide from the air to make glucose (sugar). This process is called photosynthesis and it takes place in the green leaves.
Without enough sunlight the plant cannot make enough glucose to fuel growth. Too much direct sunlight can overheat the leaf and damage the cells, which is why the optimal range is not "as much as possible."
Running a Fair Test
A controlled experiment changes only one variable at a time. All other variables are kept the same. This lets you say for certain that any difference in height was caused by the one variable you changed.
If you change both sunlight and water at the same time, you cannot tell which one caused the height difference.
Why Soil Type Matters
Different soils have different mixtures of particle sizes and nutrients. The particle size affects how well the soil holds water and air, both of which plant roots need.