(g) the different types of adaptations of organisms to their environment

The idea

Adaptations are inherited features that raise an organism's chance of surviving and reproducing in its habitat. They fall into three linked types. Anatomical (structural) adaptations are body form and structure, such as a thick insulating coat, streamlined shape, or waxy cuticle reducing water loss. Physiological adaptations are biochemical or functional processes, such as the ability to concentrate urine, produce antifreeze proteins, or regulate salt balance. Behavioural adaptations are actions or patterns of activity, such as migration, nocturnal foraging, or basking to warm the body. The same challenge, for example cold, may be met by several types at once, so classify each feature by what it actually is rather than by the habitat. A thick coat is anatomical; shivering to generate heat is physiological; huddling together is behavioural.

What earns the marks

• Anatomical (structural) adaptations are physical features of body form or structure, e.g. streamlined shape, thick fur, waxy cuticle.
• Physiological adaptations are functional or biochemical processes within the body, e.g. concentrating urine, producing antifreeze proteins, regulating salt balance.
• Behavioural adaptations are actions or activity patterns, e.g. migration, nocturnal foraging, huddling, basking.
• Adaptations are inherited features that increase the chance of survival and reproduction in a particular environment.
• A single environmental challenge may be met by more than one type of adaptation, so each feature must be classified by what it is, not by the habitat.

Common mistakes and how to put them right

• Calling any feature that helps survival 'behavioural'.

  Put it right: Behaviour must be an action or activity pattern; a body structure is anatomical and a body process is physiological.

• Treating the three types as alternatives that cannot co-occur.

  Put it right: One organism often shows anatomical, physiological and behavioural adaptations together.

• Classifying a feature by its habitat rather than its nature.

  Put it right: Decide whether the feature is a structure, a process or an action, then assign the type.

Exam tips

• Read the feature described and ask: is it a structure, a process or an action? That decides anatomical, physiological or behavioural.
• Learn two clear examples of each type so you can match unfamiliar examples to the correct category.
• Watch for distractors that describe a habitat rather than the adaptation itself; classify the feature, not the environment.