Plant Germination

Question 1

Write a method to investigate plant germination

Answer 1

1. Set up three petri dishes containing cotton wool soaked in equal amounts of water.
2. Put ten mustard seeds in each dish.
3. Put the dishes in a warm place. They must not be disturbed or moved.
4. Allow the mustard seeds to germinate. Water daily with equal amounts of water to each dish.
5. Each dish should have the same number of seedlings after the seeds have geminated. Remove excess seedlings from any dish that has too many.
6. Measure the height of each seedling in mm
7. Move the petri dishes into position.
   • Put one on a windowsill in full sunlight.
   • Put the second one in partial light.
   • Put the third one in darkness.
8. Measure the height of each seedling every day, for at least five consecutive days.
9. Record the heights in a table

Question 2

What is the independent variable?

Answer 2

Light intensity

Question 3

What is the dependant variable?

Answer 3

Growth of plant/ plant height

Question 4

What are some control variables?

Answer 4

Amount of cotton wool
Same temperature
Type of plant
Volume of water

Question 5

How should you calculate a mean?

Answer 5

Don’t ignore anomalies

Question 6

What does germination mean?

Answer 6

When a seed develops into a plant

Question 7

Explain the results.

Answer 7

The seeds that were kept in the dark have grown the most. This is because seeds usually germinate underground and they grown rapidly to reach the light. If we keep them in the dark they will mimic this, continuing to grow rapidly to reach the light. But their leaves will be smaller and yellower because once they have used their
energy stores from the seed, they are unable to photosynthesise in the dark.