IB Diploma Programme (DP) - SL & HL · Biology

D4.2 Stability and change (Ecosystems): Practice Questions

5 multiple-choice questions marked as you go, and 2 written questions with worked solutions. All on D4.2 Stability and change (Ecosystems).

7 questions14 marksFree, no account

Question 1

1 mark

In the context of ecosystem sustainability, which of the following is essential for the long-term survival of a biological community?

Question 2

1 mark

Which of the following activities contributes most significantly to an individual's ecological footprint in a developed country?

Question 3

1 mark

In an open ocean pelagic ecosystem, sustained overfishing of top predatory piscivorous fish leads to an increase in zooplanktivorous forage fish, causing a decline in large herbivorous zooplankton and a subsequent unchecked bloom of phytoplankton. What ecological phenomenon is demonstrated here?

Question 4

1 mark

Which statement correctly defines an ecological tipping point in the context of sustainability and change?

Question 5

1 mark

An enclosed forest ecosystem experiences a prolonged drought. Large canopy trees undergo severe water stress, leading to widespread mortality. The loss of canopy cover increases forest floor temperatures and desiccates litter, rendering the remaining vegetation susceptible to intense wildfires that convert the area into a stable dry savanna. What does this transition illustrate?

Question 6

5 marks

Explain how a positive feedback loop involving boreal forest wildfire frequency and climate warming can lead to an ecological tipping point.

Write your answer out first, then check it against the worked solution.

Question 7

4 marks

Ecosystems can maintain dynamic equilibrium, but severe human disturbances can trigger rapid state shifts.

a) Outline what is meant by a tipping point in an ecosystem.
b) Explain the role of positive feedback loops in driving an ecosystem past an ecological tipping point, using the example of Arctic sea ice loss.
c) Distinguish between the stability of an ecosystem with high species richness versus one with low species richness when subjected to environmental disturbance.

Write your answer out first, then check it against the worked solution.

* The content provided by thinka is generated by AI and may not always be accurate or up-to-date. Please use it as a supplementary resource and verify with official materials.

You've seen the model answer. Now get yours marked.

This page can show you how a good answer looks. It cannot tell you what your answer was missing. thinka marks your written work against the real mark scheme in about 15 seconds.

Get My Answers Marked Back to the notes

Want more questions like these? Get a fresh set on this topic, graded as you go.

Practice More