Cambridge OCR A Level · Biology A - H420

Biodiversity: Practice Questions

5 multiple-choice questions marked as you go, and 4 written questions with worked solutions. All on Biodiversity.

9 questions23 marksFree, no account
Question 1
1 mark

Which of the following describes species evenness in a habitat?

Question 2
1 mark

Which of the following international agreements is specifically concerned with regulating the trade of endangered species and their products?

Question 3
1 mark

A scientist calculated the genetic biodiversity of a rare breed of cattle. In a genome survey of 400 gene loci, 48 loci were found to be polymorphic. Calculate the proportion of polymorphic gene loci and identify which factor most likely reduces this value in captive populations.

Question 4
1 mark

A student wants to study the distribution of plant species across a transition from a sand dune to a woodland. Which sampling method would be most appropriate?

Question 5
1 mark

In a study of a meadow, 5 species were identified with the following number of individuals (n):
Species A: 25
Species B: 15
Species C: 10
Species D: 40
Species E: 10
The total number of individuals (N) is 100. Calculate the Simpson's Index of Diversity (D) for this habitat using the formula:
\( D = 1 - \sum (\frac{n}{N})^2 \)

Question 6
2 marks

Define species richness and species evenness as measures of biodiversity within a habitat.

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Question 7
3 marks

An ecologist uses a series of belt transects to study the distribution of plant species from the edge of a woodland into its center.
Identify the type of sampling being used and explain why this specific method is more appropriate than random sampling for this investigation.

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Question 8
5 marks

A scientist is calculating the genetic biodiversity of a captive population of Panthera tigris. In a genome study of 40 specific gene loci, 12 were found to be polymorphic.
Calculate the proportion of polymorphic gene loci using the formula:
\(\text{proportion of polymorphic gene loci} = \frac{\text{number of polymorphic gene loci}}{\text{total number of loci}}\)
Describe how a high value for this proportion relates to the long-term survival of the population.

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Question 9
8 marks

A student investigated the biodiversity of two different areas of a local nature reserve: a managed woodland and an unmanaged meadow. The student used quadrats to sample the plant species present in each area.

(a) Explain the difference between species richness and species evenness, and describe how these two components contribute to the total biodiversity of a habitat. (3)

(b) In the managed woodland, the student identified 12 different species. In one specific patch, they found the following counts for the three most dominant species:
- Species A: 45 individuals
- Species B: 12 individuals
- Species C: 3 individuals

Calculate the proportion of polymorphic gene loci if a genetic analysis of Species A revealed that 4 out of 25 loci studied were polymorphic. (1)

(c) The student calculated the Simpson’s Index of Diversity \(D\) for the meadow as 0.85 and for the woodland as 0.42.
(i) State what these values suggest about the stability of the meadow ecosystem compared to the woodland ecosystem. (1)
(ii) Outline three reasons why it is important to maintain biodiversity in areas like this nature reserve. (3)

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