Effect of Light on Seedlings
Biology: AQA GCSE Higher, topic 5.4.4
Effect of Light on Seedlings
The effect of light on seedlings can be demonstrated with mustard or cress seeds. Complete the following steps:
Step 1
- Place the seeds in petri dishes with damp cotton wool, and leave them in a warm place to germinate (develop).
Step 2
- Randomly divide the petri dishes into three groups and assign each group to one of the following light conditions:
- Full sunlight in a windowsill
- Darkness
- Partial light
Step 3
- Measure the height of each plant every day for a week.
Step 4
- Draw and label biological drawings to show the effects.
Step 5
- The independent variable is the lighting conditions.
- The dependent variable is the growth of the plant.
Step 6
- Phototropism can also be demonstrated by placing a seedling in a container that is open only on one side.
Test yourself on Effect of Light on Seedlings
To investigate the effect of light on plant growth, in which three conditions should the seedlings be placed?
Light Investigation
How often is the height of the seedlings measured during this investigation into the effect of light on their growth?
Which method of assigning the petri dishes to the three light conditions would produce the fairest test in this investigation?
Why is the lighting condition the independent variable in this investigation into seedling growth?