GCSE Photosynthesis practical

What gas is produced during the rate of photosynthesis practical?

• Carbon dioxide

• Oxygen

• Hydrogen

• Carbon monoxide

What apparatus could be used to measure the volume of gas more accurately?

• Beaker

• Measuring cylinder

• Gas syringe

• Conical flask

Why is counting the bubbles inaccurate? Click two answers.

• You may miss a bubble.

• The bubbles are all the same size.

• The bubbles could be different sizes.

• The stream of bubbles is too fast to count.

How could you reduce the light intensity?

• Move the bulb closer

• Move the bulb further away

• Increase the temperature

What is the independent variable for this practical?

• Light intensity

• Rate of photosynthesis

• Temperature

• Type of pondweed

What is the dependent variable for this practical?

• Light intensity

• Rate of photosynthesis

• Temperature

• Type of pondweed

Which of these are control variables? Tick three boxes.

• Light intensity

• Rate of photosynthesis

• Temperature

• Type of pondweed

• Availability of carbon dioxide

What two things do we need to measure rate of photosynthesis?

• Volume of oxygen produced

• Volume of carbon dioxide produced

• Time

• Temperature

On a hot sunny day, what factor limits photosynthesis?

• Carbon dioxide availability

• Temperature

• Light

• Chlorophyll

During the winter, what factor limits photosynthesis?

• Carbon dioxide availability

• Temperature

• Light

• Chlorophyll