Neco 2019 Biology Question 40

Practice objective / multiple choice question 40 from the 2019 Neco Biology examination.

Neco 2019 Biology Objective / Multiple Choice Hard Difficulty
Question 40 NECO • 2019 • BIOLOGY • objective

In a pond, a researcher samples five quadrats and records the number of individuals of four species as follows: Species A (algae) 40, Species B (zooplankton) 30, Species C (insect larvae) 20, Species D (small fish) 10. (a) Calculate Simpson's Diversity Index (D) and its reciprocal (1/D). (b) If a pollutant reduces the algae population by 50% in each quadrat (all other species remain unchanged), recalculate D and 1/D. (c) Discuss briefly how this change in diversity could affect the abundance of the small fish, assuming the food web remains otherwise unchanged.

Answer Options

Correct Answer A. Initial D ≈ 0.293 (1/D ≈ 3.41); after algae loss D ≈ 0.272 (1/D ≈ 3.68); the reduction in primary production is expected to cause a decline in small‑fish abundance despite the small change in the diversity index.
B. Initial D ≈ 0.250 (1\/D ≈ 4.00); after algae loss D ≈ 0.230 (1\/D ≈ 4.35); the reduction in primary production is expected to increase small‑fish abundance due to reduced competition.
C. Initial D ≈ 0.293 (1\/D ≈ 3.41); after algae loss D ≈ 0.350 (1\/D ≈ 2.86); the higher diversity after algae loss suggests a rise in small‑fish numbers.
D. Initial D ≈ 0.320 (1\/D ≈ 3.13); after algae loss D ≈ 0.300 (1\/D ≈ 3.33); the decrease in algae should have little effect on small‑fish abundance because the diversity change is minimal.
Correct Answer
A
Correct Option:
Initial D ≈ 0.293 (1/D ≈ 3.41); after algae loss D ≈ 0.272 (1/D ≈ 3.68); the reduction in primary production is expected to cause a decline in small‑fish abundance despite the small change in the diversity index.

About This Question

This is Neco 2019 Biology Question 40. It is one of the objective questions from the 2019 Neco Biology examination.

Difficulty level: Hard .

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