Practical 12

Factors Affecting Germination

You will be investigating how different environmental conditions affect the germination of a seed. Which factors will you investigate? You might like to think about:

• The amount of light available to seeds
• The amount of water available to seeds
• The amount of air available to seeds
• The temperature of the seeds

Planning:

In groups, choose one factor to investigate, and check with your teacher. How can you investigate just this one factor, making sure that other factors are not interfering? (fair test). How should you set up your experiment; how many beakers of seeds will you need? (control). How will you make sure that the seeds have a chance to germinate? How will you be able to tell if germination has taken place? Will you be able to measure any aspect of germination? Note down some important points in the Table below, and show this to your teacher before you start the experiment.

Apparatus and Materials:

• beakers
• bean seeds (soaked overnight)
• paper towels or filter paper
• water
• window with sunlight
• drawer (dark)
• refrigerator

Method

• You will need to place about 4 broad bean seeds on paper towels within a beaker.
• You then need to set up another beaker (control) so that you are able to investigate a particular factor. Don’t forget: you should only change one factor at a time, and the others should be kept the same (fair test). Clearly label each beaker to show what it contains.
• Set up the beakers so that the beans have a chance to germinate. So, for example, you will need to have at least some water present. Check with your teacher about this.
• You will now need to observe the seeds over a period of time, and record what you see. You should draw up a results table for this.
• If you have enough time and resources, you may be able to set up more beakers to investigate another factor.

Results

Draw up a Table similar to the one below, and note down what you see in each of your beakers at the time indicated (you may need to change the times depending on when you can look at the beakers). If you have decided to make measurements, you may need to construct a more detailed table.

Discussion

• What differences did you notice between the two beakers?
• What conclusions can you make? Was the factor you investigated important for germination?
• Were there any limitations to your Plan or your Method? What would you do differently if you could do this experiment again?
• If you are able to, compare your groups’ results with the results from other groups. What overall conclusions can you make? Which factors seem to be important for germination? How could this affect the way farmers or gardeners decide to plant their seeds?