a measure of how much change occurs per unit of time

the amount of light reaching a given surface area in a period of time

an idea, for example an idea about an outcome of an experiment, based on observations and understanding

a factor that can be changed during an experiment

a factor that is kept the same during an experiment

The effect of light intensity on rate of photosynthesis in algae: plan

Combined science

Pupils learned about ways in which the human body maintains a constant internal environment in response to internal and external change, including changes in temperature and water balance.

This unit explores factors affecting photosynthesis rates and focuses on planning and conducting experiments. It includes selecting techniques, accurate measurements, data analysis, and evaluating methods to improve reliability and suggest further investigations.

Photosynthesis: factors affecting the rate

Physical activity and equipment requiring safe use

What is the main product of photosynthesis?

Which part of the plant cell captures light for photosynthesis?

What is the independent variable in an experiment investigating the effect of light intensity on the rate of photosynthesis?

change of colour of universal indicator  

Which of the following is an example of a control variable in a light intensity experiment?

By using a ruler to measure the distance.

By marking a fixed position for the lamp.

By placing the plant on a stand at a set height.

By trying to keep the plant and lamp in the same position throughout.

How can the distance of the plant from the lamp be controlled in the experiment?

What would be plotted on the x-axis in a graph of light intensity and photosynthesis rate?

What is the basic purpose of photosynthesis in plants?

Where in the plant cell does photosynthesis occur?

A factor that is changed during an experiment.

A factor that doesn’t affect the results of the experiment.

What is an independent variable in an experiment?

Which type of variable is kept the same during an experiment?

Wear safety goggles and handle equipment carefully.

Ensure all equipment is correctly set up before use.

What safety measures should be considered when handling experimental apparatus?

The mass of the plant before and after the experiment.

What is measured as the dependent variable in this photosynthesis experiment?

Content guidance

Risk assessment required - equipment

Adult supervision required

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