Topic 2: individuals, populations and energy in ecosystems: practice

Question 11 mark

Spec and skills

Paper scope: Paper 1; Paper 2
Topic spec Paper 1
Topic spec Paper 2
Skill: ess-t2a-populations
Knowledge check
Environmental systems and societies, first assessment 2026, Subject brief (IBO 2023), read 29 Oct 2026

Which definition of a species is used in ESS?

Question 21 mark

Spec and skills

Paper scope: Paper 1; Paper 2
Topic spec Paper 1
Topic spec Paper 2
Skill: ess-t2a-populations
Knowledge check
Environmental systems and societies, first assessment 2026, Subject brief (IBO 2023), read 29 Oct 2026

What is the difference between a species' habitat and its niche?

Question 31 mark

Spec and skills

Paper scope: Paper 1; Paper 2
Topic spec Paper 1
Topic spec Paper 2
Skill: ess-t2a-populations
Knowledge check
Environmental systems and societies, first assessment 2026, Subject brief (IBO 2023), read 29 Oct 2026

In a nutrient-poor lake, adding phosphate makes algae grow much faster. What was phosphate acting as?

Question 41 mark

Spec and skills

Paper scope: Paper 1; Paper 2
Topic spec Paper 1
Topic spec Paper 2
Skill: ess-t2a-growth
Knowledge check
Environmental systems and societies, first assessment 2026, Subject brief (IBO 2023), read 29 Oct 2026

A population is introduced to a new island. Its numbers follow an S-shaped curve. What happens during the plateau phase?

Question 51 mark

Spec and skills

Paper scope: Paper 1; Paper 2
Topic spec Paper 1
Topic spec Paper 2
Skill: ess-t2a-growth
Knowledge check
Environmental systems and societies, first assessment 2026, Subject brief (IBO 2023), read 29 Oct 2026

Which pattern does a J-curve population usually show?

Question 61 mark

Spec and skills

Paper scope: Paper 1; Paper 2
Topic spec Paper 1
Topic spec Paper 2
Skill: ess-t2a-growth
Knowledge check
Environmental systems and societies, first assessment 2026, Subject brief (IBO 2023), read 29 Oct 2026

What is carrying capacity?