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Describe the structure and function of the nucleus - AQA - A-Level Biology - Question 1 - 2022 - Paper 1
Question 1
Describe the structure and function of the nucleus. The nucleus is a cell organelle surrounded by a nuclear envelope that consists of two layers, each with pores th... show full transcript
Worked Solution & Example Answer:Describe the structure and function of the nucleus - AQA - A-Level Biology - Question 1 - 2022 - Paper 1
Step 1
Step 2
2. Suggest one reason the scientists used biomass instead of the number of individuals of each plant species when collecting data to measure diversity.
Answer
One reason is that individual organisms could be too small or numerous to accurately count, making it difficult to distinguish different species.
Step 3
3. Use this equation to calculate the index of diversity for the data in Table 1.
Answer
To calculate the index of diversity (d), we first find the total shoot biomass (N):
Total shoot biomass = 2 + 4 + 5 + 7 + 15 + 36 + 51 = 120 g/m²
Next, we apply the formula: d = 1 - rac{n^2}{N^2}
Where n is the biomass of each plant species. Using the values from Table 1:
d = 1 - rac{(2^2 + 4^2 + 5^2 + 7^2 + 15^2 + 36^2 + 51^2)}{(120)^2} d = 1 - rac{(4 + 16 + 25 + 49 + 225 + 1296 + 2601)}{14400} d = 1 - rac{4216}{14400}
So, the index of diversity is approximately 0.71.
Step 4
4. Suggest and explain how the plant species index of diversity would be different in these areas previously used to grow crops.
Answer
The plant species index of diversity would likely be lower in areas previously used for cropping. This is because intensive agricultural practices typically reduce biodiversity by favoring certain species (crops) while eliminating others. The removal of native species and alteration of soil conditions can decrease the resilience of the ecosystem, thus leading to a less diverse plant community compared to areas that have never been used for agriculture.