Design a system that grows food without soil, test it for four weeks in a simulation, then run a controlled experiment on it. Everything you record here goes into your lab write-up, due Wednesday, October 7.
Hydroponics is growing plants without soil. The roots get water and nutrients from a nutrient solution instead. People use it in Antarctica, in deserts, on city rooftops, and on empty lots where the soil is poor.
| A plant needs | In soil | In hydroponics |
|---|---|---|
| Support | Soil holds the roots | Foam platform, net cups, clay pebbles |
| Water | Rain, watering | The tub |
| Nutrients | Minerals in the soil | Nutrient solution mixed into the water |
| Oxygen for roots | Air spaces in the soil | Air pump, tubing, and air stone |
| Light | The sun | The sun or a grow light |
Source: Miller & Levine Biology, pages 30 and 34.
Choose your parts. Your design must give the plants all five things they need, cost $60 or less, and keep every plug away from the water.
Plant three seedlings and run the system for 28 days. When it finishes, the simulation weighs each plant and checks its roots and leaves. If your design struggles, go back to Step 2, change one thing, and grow again. Every run is saved in your trial log.
| Run | What changed | Cost | Avg mass (g) | Roots | Leaves |
|---|
Start from your design. Change only one variable, keep everything else the same, and grow three plants in each setup. Write your plan before you run it.
Answer in complete sentences. Use numbers from your data table as evidence.
This is everything you did in the lab. Copy it into a Google Doc. You will use it to write your lab write-up.
| Problem, criteria, and constraints | 3 |
| Labeled drawing and what each part does | 4 |
| Materials and cost | 2 |
| Test plan | 4 |
| Results table and bar graph | 3 |
| Analysis | 4 |
| Conclusion and redesign | 5 |