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10. Figure 24 shows the world human population from 1800 to 2015 - Edexcel - GCSE Biology - Question 10 - 2020 - Paper 1
Question 10
10. Figure 24 shows the world human population from 1800 to 2015. (a) In 2015, 13% of the world human population were classified as malnourished. Calculate, using F... show full transcript
Worked Solution & Example Answer:10. Figure 24 shows the world human population from 1800 to 2015 - Edexcel - GCSE Biology - Question 10 - 2020 - Paper 1
Step 1
In 2015, 13% of the world human population were classified as malnourished.
Answer
To find the number of people classified as malnourished in 2015, we first need to determine the total world population in that year. From Figure 24, the world population in 2015 is approximately 7 billion.
Calculating 13% of this population:
Thus, approximately 0.91 billion people were classified as malnourished in 2015.
Step 2
Describe the laboratory test for protein.
Answer
A common laboratory test for protein involves using a reagent, such as Biuret. The procedure is as follows:
- Add Biuret reagent to the sample being tested. The reagent contains sodium hydroxide and copper sulfate.
- Observe the color change; if proteins are present, the solution will change from blue to mauve or purple, indicating the presence of protein.
Step 3
Calculate the rate of increase in the mass of meat eaten in the world from 2000 to 2010.
Answer
From Figure 25, we observe the mass of meat eaten in 2000 and 2010. Let's assume:
- Mass in 2000 = 200 million tonnes
- Mass in 2010 = 300 million tonnes
The increase in mass = 300 - 200 = 100 million tonnes over 10 years.
To find the rate of increase per year:
ext{Rate} = rac{100 ext{ million tonnes}}{10 ext{ years}} = 10 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 that of plants because of the energy pyramid concept. Specifically, energy loss occurs at each trophic level where only about 10% of the energy is transferred from one level to the next. Thus, it requires a larger biomass of plants to support a smaller biomass of cattle. This results in a smaller area for cattle on the energy pyramid.
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 the mass of meat eaten can impact food security by shifting agricultural priorities away from cereals and vegetables needed for human consumption towards livestock production. This can lead to:
- Resource depletion: More land, water, and feed resources will be needed for livestock, reducing availability for crops.
- Price increases: As demand for meat rises, the price of grain may increase, making it less accessible for vulnerable populations.
- Sustainability concerns: Higher livestock production is often linked to environmental issues, which can threaten long-term food availability.
Overall, emphasizing meat consumption may lead to decreased food availability for the broader population.