The algae make glucose by photosynthesis. Which two substances do the algae need for photosynthesis? Tick (*) two boxes. - Carbon dioxide - Nitrogen - Oxygen - Water What is the source of energy for photosynthesis? Tick (*) one box. - Light - Mineral ions - Protein - Water Which pyramid of biomass is correct for the food chain shown in Figure 4? Tick (*) one box. - (a) - (b) - (c) - (d) Too many herring were caught in the 1960s. Calculate the percentage decrease in the biomass of adult herring between 1960 and 1970. Use the equation: percentage decrease = \(rac{(biomass \: in \: 1960 - biomass \: in \: 1970)}{biomass \: in \: 1960} \times 100\) Give your answer to the nearest whole number. Percentage decrease = ______ % From 1977, laws were introduced to help conserve herring. Describe the change in biomass of adult herring from 1977 to 1990. Use data from Figure 5 in your answer. One of the laws was to control mesh size of fishing nets. Explain how the control of mesh size of fishing nets has helped to conserve stocks of herring.

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The algae make glucose by photosynthesis - AQA - GCSE Biology - Question 3 - 2021 - Paper 1

Question 3

The algae make glucose by photosynthesis. Which two substances do the algae need for photosynthesis? Tick (*) two boxes. - Carbon dioxide - Nitrogen - Oxygen - Wa... show full transcript

Worked Solution & Example Answer:The algae make glucose by photosynthesis - AQA - GCSE Biology - Question 3 - 2021 - Paper 1

Step 1

Which two substances do the algae need for photosynthesis?

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Answer

The two substances that algae need for photosynthesis are carbon dioxide and water.

Step 2

What is the source of energy for photosynthesis?

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Answer

The source of energy for photosynthesis is light.

Step 3

Which pyramid of biomass is correct for the food chain shown in Figure 4?

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Answer

The correct pyramid of biomass for the food chain shown in Figure 4 is option (b).

Step 4

Calculate the percentage decrease in the biomass of adult herring between 1960 and 1970.

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Answer

Given the biomass values, suppose it was 2.3 million tonnes in 1960 and 0.5 million tonnes in 1970. Using the formula:

percentage \: decrease = \left( \frac{(2.3 - 0.5)}{2.3} \right) \times 100 = 78.26\% \approx 78\%

Step 5

Describe the change in biomass of adult herring from 1977 to 1990.

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Answer

From 1977 to 1990, the biomass of adult herring showed an increase. This can be attributed to the laws that were introduced to help in conservation efforts.

Step 6

Explain how the control of mesh size of fishing nets has helped to conserve stocks of herring.

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Answer

The control of mesh size of fishing nets ensures that smaller, younger herring are not caught. This allows them to escape and reproduce, leading to a sustainable herring population.

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Questions answered

The algae make glucose by photosynthesis - AQA - GCSE Biology - Question 3 - 2021 - Paper 1

Worked Solution & Example Answer:The algae make glucose by photosynthesis - AQA - GCSE Biology - Question 3 - 2021 - Paper 1

Which two substances do the algae need for photosynthesis?

What is the source of energy for photosynthesis?

Which pyramid of biomass is correct for the food chain shown in Figure 4?

Calculate the percentage decrease in the biomass of adult herring between 1960 and 1970.

Describe the change in biomass of adult herring from 1977 to 1990.

Explain how the control of mesh size of fishing nets has helped to conserve stocks of herring.

Join the GCSE students using SimpleStudy...

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