Revision NotesExam Questions
GCSEScienceOCRCombined Science A (Gateway)BiologyExam QuestionsCell Level SystemsPhotosynthesis

Photosynthesis (OCR GCSE Combined Science A (Gateway): Biology)

Exam Questions

34 mins12 questions

Select a question set to download for
Photosynthesis

Select an answer set to view for
Photosynthesis

1a
Sme Calculator1 mark

Two students investigate photosynthesis. Look at the notes from their investigation.

  Aim of the experiment  

To use pondweed to see how light intensity affects the rate of photosynthesis.  

Method

  1. Set up the apparatus as in the diagram.

  2. Leave the pondweed for five minutes so it can adjust to the new light intensity.

  3. Count the number of bubbles given off by the pondweed in one minute.

  4.  Move the lamp 10cm further away from the beaker.

  5. Leave the pondweed for five minutes so it can adjust again.

  6. Count the number of bubbles given off by the pondweed in one minute.

  7. Repeat by moving the lamp further away from the beaker by 10cm intervals until 50cm is reached.   

q18-2-paper1f-nov2020-ocrgcsebio

What is the independent variable in their investigation?

How did you do?

1b
Sme Calculator4 marks

(i) Explain why counting the number of bubbles will not give an accurate measure of the rate of photosynthesis.

[2]

(ii) Describe how the students could develop their investigation to improve the accuracy of their results.

[2]

How did you do?

1c
Sme Calculator6 marks

The table shows the results.

Distance from lamp to beaker (cm)

Number of bubbles given off (per minute)

10

30

20

14

30

6

40

2

50

0

(i) One student started to draw a graph but did not finish.

Complete the graph using the results in the table and draw a curve of best fit.

q18ci-paper1f-nov2020-ocrgcsebio

[4]

(ii) Write down what the students could conclude from their investigation.

Include data from the results table in your answer.

[2]

How did you do?

Did this page help you?

2a
Sme Calculator1 mark

Photosynthesis involves reactions that are endothermic.

What is meant by the term endothermic reaction?

How did you do?

2b
Sme Calculator1 mark

The graph is from an experiment to show the effect of temperature on the rate of photosynthesis.

q21b-paper1h-june2018-ocrgcsebio

Draw a line of best fit.

How did you do?

2c
Sme Calculator3 marks

Higher Tier only

Look at the graph. It shows how light intensity affects the rate of photosynthesis.

The lines show different carbon dioxide concentrations and temperatures.

q21c-paper1h-june2018-ocrgcsebio

Explain what is limiting the rate of photosynthesis at the three points A, B and C on the graph.

Use evidence from the graph in your answer.

How did you do?

Did this page help you?

3a
Sme Calculator3 marks

Photosynthesis takes place inside chloroplasts.

(i) Complete the chemical equation for photosynthesis.

6CO2 + .......................... → C6H12O6 + ........................

[2]

(ii) Energy is taken in from the surroundings for photosynthesis to take place.

What name is used to describe reactions that take in energy?

[1]

How did you do?

3b
Sme Calculator3 marks

The graph is from an experiment to show the effect of temperature on the rate of photosynthesis.

q17d-paper1f-june2018-ocrgcsebio

(i) What is the optimum temperature for photosynthesis in this experiment?

[1]

(ii) The rate of photosynthesis was recorded in 5°C intervals.

The experiment could be improved to get a more precise value for the optimum temperature.

Explain how.

[2]

How did you do?

Did this page help you?

4
Sme Calculator4 marks

A student investigates the plants growing underneath a tree.

He lays out a tape measure on the ground, starting at the tree. He then places a quadrat on the ground. He measures the percentage of the ground in the quadrat that is covered by plants. He repeats this every metre away from the tree.

The table shows his results.

Distance from the tree (m)

Percentage of ground covered by plants (%)

1

10

2

15

3

18

4

22

5

50

6

58

7

62

8

64

The student thinks that shade from the tree is affecting the plants.

Explain how the student’s results show this.

How did you do?

Did this page help you?