Question 35
Planning an investigation into the effect of fertilisers on plant growth
You are going to plan an experiment to find out how fertiliser affects the rate of growth of duckweed. You may be able to do your experiment after you have planned it.
Duckweed is a tiny plant. There are lots of different species of duckweed, and they grow in most countries in the world. Some kinds of duckweed have just a single leaf, while others may have little groups of leaves. The leaves float on the water surface. All duckweed plants have roots that dangle down into the water.
- You could investigate effects of different kinds of fertiliser, or you could use just one kind and try different quantities of it.
- You could grow your duckweed in small containers – for example, Petri dishes.
- You could measure how much the duckweed grows by counting the number of leaves.
Part 1: Planning the investigation
Decide on a hypothesis that you will test.
You are going to plan an experiment to find out how fertiliser affects the rate of growth of duckweed. You may be able to do your experiment after you have planned it.
Duckweed is a tiny plant. There are lots of different species of duckweed, and they grow in most countries in the world. Some kinds of duckweed have just a single leaf, while others may have little groups of leaves. The leaves float on the water surface. All duckweed plants have roots that dangle down into the water.
- You could investigate effects of different kinds of fertiliser, or you could use just one kind and try different quantities of it.
- You could grow your duckweed in small containers – for example, Petri dishes.
- You could measure how much the duckweed grows by counting the number of leaves.
Part 1: Planning the investigation
Decide on a hypothesis that you will test.
