Niche and adaptations to the environment

Plant Structure and Function, Biodiversity and Conservation · Niche, allele frequency and conservation · note 1 of 4

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Niche and adaptations to the environmentSpec 4.19

In short

A niche is the role of a species in its habitat, including how it obtains food, the abiotic conditions it tolerates and its interactions with other species. Adaptations that fit organisms to their niche may be behavioural, anatomical or physiological. Two species cannot occupy exactly the same niche in the same place indefinitely, because they would compete.

Niche: The role of a species within its habitat: how it obtains food and other resources, the abiotic conditions it tolerates and the biotic interactions it has with other species (such as feeding relationships, competition and predation).

Each species in a habitat has its own niche. If two species have very similar niches they compete for the same resources, and one is likely to decline, so competition tends to separate the niches of species living together. Organisms are adapted to their niche: a feature that helps survival and reproduction in a particular environment is an adaptation. Adaptations are the result of natural selection.

Types of adaptation
Type	Meaning	Examples
Behavioural	The way an organism acts	Hibernation in winter; migration; nocturnal activity in desert animals to avoid the heat of the day; courtship displays; basking to warm up
Anatomical	Structural features of the body that can be seen in a dissection or section	Marram grass has rolled leaves, hairs and sunken stomata that reduce transpiration; thick fur and a layer of fat in polar bears; large ears in desert foxes that lose heat
Physiological	Processes inside the body, including biochemical ones	Kangaroo rats produce very concentrated urine, conserving water; antifreeze proteins in polar fish; production of venom or toxins; slowed metabolism during hibernation

Table-style diagram of behavioural, anatomical and physiological adaptations of a desert rodent in a hot dry habitat and a polar bear in a cold habitat. — Behavioural, anatomical and physiological adaptations in a hot dry habitat and a cold habitat.

Exam tip:

When asked to discuss adaptations, name the type (behavioural, anatomical or physiological), give the feature and link it to survival in that environment, for example by reducing water loss.

Written and checked against the Edexcel International AS Level Biology (XBI11) specification · Updated October 2026

Frequently asked questions

What is a niche in biology?

A niche is the role of a species within its habitat: how it obtains food and other resources, the abiotic conditions it tolerates and how it interacts with other species. Each species has its own niche, and species with very similar niches compete, so one may be excluded.

What are behavioural, anatomical and physiological adaptations?

Behavioural adaptations are how an organism acts, such as hibernation or migration. Anatomical adaptations are structural features, such as the rolled leaves of marram grass. Physiological adaptations are internal processes, such as a kangaroo rat producing concentrated urine. All of them increase survival and reproduction in the environment.

How do you use the Hardy-Weinberg equation?

Find q² from the frequency of the homozygous recessive phenotype, take the square root to get q, then calculate p = 1 − q. Use p² for homozygous dominant and 2pq for heterozygous. If later generations differ from the predicted frequencies, allele frequencies are changing.

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