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Lemurs are small mammals - AQA - A-Level Biology - Question 5 - 2022 - Paper 1
Question 5
Lemurs are small mammals. Lemurs live in trees and feed on leaves and fruit. Scientists used a computer program to predict the expected distribution of two species o... show full transcript
Worked Solution & Example Answer:Lemurs are small mammals - AQA - A-Level Biology - Question 5 - 2022 - Paper 1
Step 1
Using Figure 2, give three conclusions you can make about the distribution of these lemur species.
Answer
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Eulemur rufifrons is primarily distributed below the river, indicating that this species prefers lower elevations.
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The actual distribution of Eulemur rufifrons is similar to the expected distribution found through the computer program, highlighting the effectiveness of environmental predictions.
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Eulemur rufus is found in a slightly less than expected distribution based on the environmental needs, suggesting variability in habitat suitability.
Step 2
Using all the information, suggest how speciation happened to produce two species of lemur.
Answer
Speciation likely occurred through geographical isolation of populations, preventing interbreeding. Over time, the populations experienced different selection pressures due to varying environmental conditions, leading to reproductive isolation. Genetic divergence resulted from these factors, facilitating the emergence of Eulemur rufus and Eulemur rufifrons as distinct species.
Step 3
Step 4
Using the information provided, calculate how many lemurs in the second sample were marked.
Answer
Using the formula for mark-recapture:
ext{Estimation of total population} = rac{ ext{Number marked in first sample} imes ext{Total number in second sample}}{ ext{Number marked in second sample}}
Given that:
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Number marked in first sample = 30
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Total number in second sample = 25
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Total population estimated = 250, we can rearrange the formula:
ext{Number marked in second sample} = rac{30 imes 25}{250} = 3 ext{ lemurs were marked in the second sample.}