Science Experiments / Week 6
Week 6 of 6
Life Science and Ecosystems
Big question
What do living things need to grow and survive?
- Seed Growth Lab
- 45-60 minutes (plus daily check-ins for a week)
This week follows the science loop
AskPredictTestObserveExplainImprove
The big idea
- Living things need water, air, light, space, and the right environment to survive.
- Plants and animals interact with the living and nonliving parts of their ecosystem.
- Scientists observe living systems over time to learn how they change.
- Engineers can design tools that help living things grow or survive.
Living things - plants, animals, even you - need certain things to stay alive: water, air, light, space, and a place that suits them. All of the living and nonliving things in one area, working together, make an ecosystem. A garden has plants and bugs (living) and also soil, water, and sunlight (nonliving), and they all depend on each other. Unlike a one-day experiment, living things change slowly, so scientists watch them over days and weeks. This week you will grow a seed and change one thing about how it lives, then observe over time which conditions help it grow best.
Words to know
- Living
- Something that grows, needs food or water, and can make more of itself, like a plant.
- Nonliving
- Something that is not alive, like water, rocks, or sunlight.
- Ecosystem
- All the living and nonliving things in one area, working together.
- Environment
- The surroundings a living thing lives in.
- Germinate
- When a seed starts to grow and sprout into a plant.
- Survive
- To stay alive by getting what you need.
Materials
- A few dried beans or fast-growing seeds
- Clear cups or resealable plastic bags
- Paper towels
- Water
- A sunny windowsill and a dark spot like a cupboard
- A notebook to record what you see each day
Safety
- Do not eat the seeds or beans, even though they are food.
- Wash your hands after handling seeds, soil, or wet paper towels.
- Wipe up any water so no one slips.
Experiment: Seed Growth Lab
Predict first
Before you touch any materials, write down what you think will happen in this experiment - and why. Making a prediction first is what turns building into science. You will compare your prediction to what you actually observe.
Steps
- 1
Ask: What does a seed need to grow best - water, light, or both?
- 2
Fold a damp paper towel into each clear cup and tuck a seed against the side so you can watch it.
- 3
Set up seeds with different conditions: one with water and light, one with water in the dark, and one with light but no water.
- 4
Predict: Which seed do you think will grow best? Write down your prediction.
- 5
Test fairly: Keep the seeds the same and change only one condition at a time.
- 6
Observe over time: Check every day for about a week. Draw and measure what you see, and write the date.
- 7
Explain and improve: Compare the seeds, explain which conditions helped, then design a better setup and grow another seed to test it.
Why it happens
A seed holds a tiny baby plant and a small store of food. When it gets water, air, and warmth, it germinates - the baby plant wakes up, uses its stored food, and sprouts. Once leaves appear, the plant needs light to make its own food and keep growing. That is why the seed with no water cannot start, and the seed in the dark sprouts but then grows weak and pale. What you see is direct evidence of what living things need to survive.
How engineers use this
Engineers design tools that help living things grow and survive: greenhouses that trap warmth and light, drip systems that water plants slowly, self-watering pots, and even habitats and shelters for animals. Understanding what living things need is the first step to designing something that helps them.
What did you notice?
Look back at your prediction and your results, then talk these through together.
- Which seed grew the best, and which grew the worst?
- What happened to the seed with no water? With no light?
- Why do scientists have to watch this experiment for many days?
- What living and nonliving things did your seed need?
Reflect
Draw how your best seed changed over the week and write one sentence about what living things need.
Mini challenge
Design the best growing setup you can and predict how tall your seed will grow in one week.
Want to go further?
Build a mini ecosystem in a clear jar with soil, a small plant, and a little water, and observe how it changes over two weeks.
Before you finish
- I set up seeds with different conditions and one fair change.
- I predicted which seed would grow best.
- I observed and recorded the seeds over several days.
- I can explain what living things need to survive.
- I designed a better setup and tested it.
Finished the experiment and your reflection? Mark this week complete to track your progress through the 6-week course.
Lab journal
Write your own science notes as you go - they follow the same loop you used this week. Notes are saved on this device only; nothing is sent anywhere. You can also print this lesson and write by hand.
What did you want to find out?
What did you think would happen, and why?
What one thing did you change to keep it a fair test?
What did you see, hear, or measure?
Use what you noticed as your evidence.
What would you change to make it work better?
Draw what happened
Sketch your experiment or your improved design, and circle the part you changed.