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Figure 7 shows the world human population from 1800 to 2015 - Edexcel - GCSE Biology - Question 4 - 2020 - Paper 1
Question 4
Figure 7 shows the world human population from 1800 to 2015. (a) In 2015, 13% of the world human population were classified as malnourished. Calculate, using Figure... show full transcript
Worked Solution & Example Answer:Figure 7 shows the world human population from 1800 to 2015 - Edexcel - GCSE Biology - Question 4 - 2020 - Paper 1
Step 1
Calculate, using Figure 7, how many people were classified as malnourished in 2015.
Answer
To find out how many people were classified as malnourished, we first need to ascertain the world population in 2015 using Figure 7. The graph indicates that the world population was approximately 7 billion in 2015.
To calculate the number of malnourished individuals:
ext{Number of malnourished} = ext{World Population} imes ext{Percentage of Malnourished}
= 7 imes 0.13 = 0.91 ext{ billion}.
Step 2
Describe the laboratory test for protein.
Answer
The laboratory test for protein involves the use of a reagent called Biuret.
- Add Biuret Reagent: Introduce Biuret reagent to the sample solution.
- Observe Color Change: If protein is present, a color change occurs, turning from blue to mauve or purple.
Step 3
Calculate the rate of increase in the mass of meat eaten in the world from 2000 to 2010.
Answer
From Figure 8, we note:
- Mass of meat eaten in 2000 = 225 million tonnes
- Mass of meat eaten in 2010 = 275 million tonnes
To find the rate of increase:
- Calculate Increase: ext{Increase} = ext{Mass in 2010} - ext{Mass in 2000} = 275 - 225 = 50 ext{ million tonnes}
- Calculate Rate of Increase Per Year: The duration from 2000 to 2010 is 10 years. ext{Rate} = rac{ ext{Increase}}{ ext{Number of Years}} = rac{50}{10} = 5 ext{ million tonnes per year}.
Step 4
Explain why the area labelled cattle is smaller than the area labelled plants.
Answer
The area labelled cattle is smaller than the area labelled plants for a few reasons:
- Energy Transfer: There is less energy available in cattle since only a fraction of the energy obtained from plants is transferred to them.
- Not All Plants are Consumed: Not all of the plant material is consumed by cattle, leading to inefficiencies in energy transfer.
- Metabolic Energy Use: Some energy from the plants is utilized by the cattle for their own metabolic processes, leading to loss of energy in conversion.
Step 5
Explain how a large increase in the mass of meat eaten will decrease food security in the future.
Answer
A large increase in meat consumption can jeopardize food security for several reasons:
- Resource Allocation: Farming meat generally requires more land and resources compared to growing plant-based foods, which can lead to less arable land available for human food production.
- Inefficient Production: Meat production is less efficient in terms of food yield per unit area, meaning that less food is produced (per acre) compared to crop farming.
- Nutritional Impacts: High meat consumption is often linked to health issues, which can affect productivity and the overall ability of people to secure food sustainably.