Photosynthesis and respiration
What happens to a leaf kept in the dark?
Does a plant leaf need light to keep making food?
Watch first
Watch a leaf turn light, water and carbon dioxide into sugar.
What you need
Tick each one as you find it — 0 of 4 ready.
Plan the fair test
- Change: Whether the leaf gets light
- Measure: The colour and firmness of the leaf
- Keep the same: Same plant, same watering, same room temperature
Objectives this evidences
- Understand the reactants in, and products of, photosynthesis, and a word summary for photosynthesis
Do it, one step at a time
Step 1 of 4
- Step 1. Choose two similar leaves on the same plant. Photograph or sketch both.
- Step 2. Wrap one leaf completely in foil so no light reaches it. Leave the other uncovered.
- Step 3. Keep the plant in its normal spot and water it as usual for five days.
- Step 4. Unwrap the leaf and compare the two. Record the colour of each.
What should happen
The covered leaf turns paler and limper: no light means no photosynthesis, so no food made.
Think about: Why use two leaves on the same plant instead of two different plants?
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
Photosynthesis and respiration quiz
4 questions from the lessons in this stage. No timer, and you can try again as many times as you like.