1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
: Questions and Answers 3/7/2026
AQA GCSE Bioenergetics GraspIT – Questions
A: Bioenergetics Part 1 - Photosynthetic reaction, rate of photosynthesis and use of
glucose from photosynthesis.
1. Phytoplankton are microscopic aquatic plants. They utilise the energy transferred from the sun for
photosynthesis.
Scientists working in the North Sea collected 500 samples of sea water at the same depth and location
every month for a whole year. They measured the number of phytoplankton and water temperature for
each sample and calculated the mean. The graph shows the mean number of phytoplankton and water
temperature per month.
190 000
100 000
a) Explain why the numbers of phytoplankton are lower in winter months. (2)
b) Calculate the percentage decrease in numbers of phytoplankton between May and July. Write your
answer to 3 significant figures. (3)
c) Suggest the cause and reason why the numbers of phytoplankton fall at the start of summer. (2)
better hope − brighter future
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf 3/7/2026, 7:45:28 PM
, 1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
: Questions and Answers 3/7/2026
AQA GCSE Bioenergetics GraspIT – Questions
2. Van Helmont was a scientist born in the Netherlands in 1580. It was generally believed at that time that
plants gained mass by eating soil.
Van Helmont designed an experiment to test this idea. The results of his experiment are seen below.
Only water was
added for five years.
Willow plant in an iron Willow plant in same iron
pot. pot.
Willow plant has a Willow plant has a mass of
mass of 2.5kg 77.3kg
Mass of dry soil is 91kg Mass of dry soil is 90.043kg
a) Write a conclusion for this experiment using only the information provided. Explain your reasoning. (4)
b) List two extra investigations that would be needed to prove that the plant gained mass due to
photosynthesis occurring. (2)
3. There is a total of 7000 x 109 tonnes of carbon dioxide in the atmosphere and photosynthesis converts
100 x 109 tonnes per year into carbon compounds such as carbohydrates, protein or lipids. We call this
carbon fixing.
a) Calculate as a percentage how much carbon is fixed per year from the atmosphere. Express your
answer to 2 significant figures. (2)
b) Suggest 2 reasons why the amount of carbon dioxide in the atmosphere stays relatively constant. (2)
better hope − brighter future
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf 3/7/2026, 7:45:28 PM
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
: Questions and Answers 3/7/2026
AQA GCSE Bioenergetics GraspIT – Questions
A: Bioenergetics Part 1 - Photosynthetic reaction, rate of photosynthesis and use of
glucose from photosynthesis.
1. Phytoplankton are microscopic aquatic plants. They utilise the energy transferred from the sun for
photosynthesis.
Scientists working in the North Sea collected 500 samples of sea water at the same depth and location
every month for a whole year. They measured the number of phytoplankton and water temperature for
each sample and calculated the mean. The graph shows the mean number of phytoplankton and water
temperature per month.
190 000
100 000
a) Explain why the numbers of phytoplankton are lower in winter months. (2)
b) Calculate the percentage decrease in numbers of phytoplankton between May and July. Write your
answer to 3 significant figures. (3)
c) Suggest the cause and reason why the numbers of phytoplankton fall at the start of summer. (2)
better hope − brighter future
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf 3/7/2026, 7:45:28 PM
, 1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
: Questions and Answers 3/7/2026
AQA GCSE Bioenergetics GraspIT – Questions
2. Van Helmont was a scientist born in the Netherlands in 1580. It was generally believed at that time that
plants gained mass by eating soil.
Van Helmont designed an experiment to test this idea. The results of his experiment are seen below.
Only water was
added for five years.
Willow plant in an iron Willow plant in same iron
pot. pot.
Willow plant has a Willow plant has a mass of
mass of 2.5kg 77.3kg
Mass of dry soil is 91kg Mass of dry soil is 90.043kg
a) Write a conclusion for this experiment using only the information provided. Explain your reasoning. (4)
b) List two extra investigations that would be needed to prove that the plant gained mass due to
photosynthesis occurring. (2)
3. There is a total of 7000 x 109 tonnes of carbon dioxide in the atmosphere and photosynthesis converts
100 x 109 tonnes per year into carbon compounds such as carbohydrates, protein or lipids. We call this
carbon fixing.
a) Calculate as a percentage how much carbon is fixed per year from the atmosphere. Express your
answer to 2 significant figures. (2)
b) Suggest 2 reasons why the amount of carbon dioxide in the atmosphere stays relatively constant. (2)
better hope − brighter future
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf
1007049098-AQA-Biology-Bioenergetics-GraspIT-GCSE-Re-usable-Worksheet.pdf 3/7/2026, 7:45:28 PM
