CourseCourseQ BankQuestion BankDocsDocuments

B4.2.1—Ecological niche

An ecological niche is a species role in a community, including habitat, feeding, activity, reproduction, interactions and tolerance ranges across ecosystems.

Syllabus
First assessment 2025
Objective
B4.2.1
Level
SL

Exam analysis

Chance of appearing3%of analysed past papers
Latest appearanceNovember 2020
Most common paperPaper3
Typical marks2–3

Common command terms

  • Explain
  • Identify

Scoring notes

Common mistake
Treating niche as only the place where an organism lives.

Recent exam appearances

November 2020Paper3 ["SL"] · TZ012(c)[ 2 ]B4.2.1—Ecological niche
May 2015Paper3 ["SL"] · TZ121(b)[ 2 ]B4.2.1—Ecological niche
May 2013Paper3 ["SL"] · TZ2G2(a)[ 3 ]B4.2.1—Ecological niche
May 2011Paper3 ["SL"] · TZ2G2(a)[ 2 ]B4.2.1—Ecological niche
Practice this objective

Coverage 2011–2020 · Updated 15 Jul 2026

A Niche Describes How a Species Makes a Living

An ecological niche is the full role of a species: the conditions it tolerates, resources it uses and interactions that affect its survival and reproduction.

A niche includes both abiotic requirements and biotic relationships such as competition, predation and mutualism. Two species can share a habitat yet occupy different niches.

Describe a niche with: physical limits; food or resource use; timing or location; interactions with other species.

Two birds may nest in the same forest but feed at different heights and times, reducing direct competition.

Niche is not just habitat. Habitat is where a species lives; niche explains how it lives there.

Ecological niche

Assessment in practice

2–3 marks
How it is assessed

This objective is assessed through structured response, commonly using Explain / Identify.

Command terms

Explain / Identify

What earns marks

Build the answer around this relationship: A niche is the ecological role or mode of existence of a species.

Watch for

Treating niche as only the place where an organism lives.

Representative question

Question 1

[Maximum number: 3]

Explain the niche concept.

Niches, Nutrition, And Competition

A niche is the role of a species in a community, including habitat, abiotic tolerances, nutrition, activity, reproduction, and interactions. The evidence should match the question: nutrition mode, oxygen tolerance, feeding adaptation, predator-prey interaction, plant light strategy, fundamental versus realized niche, or competitive exclusion.

  • Definition answers should include role plus habitat/resources/interactions, not only place.
  • Nutrition modes explain how organisms obtain carbon, energy, or organic matter.
  • Adaptation examples should be linked to feeding, defence, light harvesting, or competition.
  • Fundamental versus realized niche and competitive exclusion are tested together because interactions narrow where species actually live.

Concept essentials

  • A niche is the ecological role or mode of existence of a species.
  • Niche includes habitat, feeding, activity, reproduction and interactions.
  • Species in similar habitats can have different niches.
  • Abiotic tolerance ranges contribute to a species niche.