A level-readyAll subjects · Biology · WBI12 (Unit 2)
Niches and adaptation
Each species has its own way of living in a habitat, its niche. Adaptations of three kinds suit organisms to their niche.
The niche
A niche is the role of a species in its habitat: what it eats, where it lives, when it is active, and how it interacts with other organisms and with abiotic factors such as temperature and water.
If two species try to occupy exactly the same niche in the same place, they compete and one will be outcompeted, so each niche is occupied by one species.
Types of adaptation
- Behavioural: how an organism acts. Many desert animals are active at night (nocturnal) and shelter in burrows by day, avoiding heat and water loss; many birds migrate.
- Anatomical (structural): body features. The fennec fox has large ears with many blood vessels that radiate heat; cacti have spines instead of leaves to reduce water loss.
- Physiological: body processes. Desert kangaroo rats produce very concentrated urine; camels let their body temperature rise during the day, so they sweat less and save water.
Adaptation and selection
Adaptations arise by natural selection: individuals with features better suited to their niche are more likely to survive and reproduce, so their alleles become more common in later generations.
Worked example
Classify: (a) a lizard basking in the sun to warm up; (b) thick fur in an Arctic fox; (c) a plant closing its stomata in hot, dry weather.
- (a) an action: behavioural.
- (b) a body structure: anatomical.
- (c) a body process: physiological.
Answer: (a) behavioural, (b) anatomical, (c) physiological.
Check yourself
- What is a niche?
- The place where an organism lives
- All the organisms in an area
- The role of a species in its habitat, including how it interacts with biotic and abiotic factors
- The number of species in a habitat
Show answer
The role of a species in its habitat, including how it interacts with biotic and abiotic factors. Habitat is where it lives; niche is how it lives there.
- Which is a behavioural adaptation?
- A desert rodent staying in its burrow during the day
- Large ears in a fennec fox
- Concentrated urine in a kangaroo rat
- Spines on a cactus
Show answer
A desert rodent staying in its burrow during the day. An action is behavioural.
- Which is an anatomical adaptation?
- Migrating south in winter
- Producing concentrated urine
- Large ears that radiate heat in the fennec fox
- Hunting at night
Show answer
Large ears that radiate heat in the fennec fox. Body structure is anatomical.
- Which is a physiological adaptation?
- A camel's broad feet
- A camel allowing its body temperature to rise during the day
- A bird migrating
- A lizard basking in the sun
Show answer
A camel allowing its body temperature to rise during the day. A body process is physiological.
- Two species occupy exactly the same niche in a habitat. What is most likely?
- The two will thrive equally forever
- They will become one species
- Neither will be affected
- One will outcompete the other
Show answer
One will outcompete the other. Competition for identical resources means one loses out.
- How do adaptations arise in a population?
- Because individuals need them
- By natural selection over many generations
- By learning within one lifetime
- By acquired characteristics being inherited
Show answer
By natural selection over many generations. Better-adapted individuals pass on their alleles.
Sources
Last updated 7 November 2026. Spotted a mistake? Tell us.