Adaptations: Organisms have features (adaptations) that enable them to survive in the conditions in which they normally live. These adaptations may be structural, behavioural or functional.

The idea

An adaptation is any inherited feature that raises an organism's chance of surviving and reproducing in its habitat. Structural adaptations are body parts, such as a polar bear's thick fur and small ears reducing heat loss, or a cactus's spines reducing water loss and deterring herbivores. Behavioural adaptations are actions, such as migrating, hibernating or basking in the sun. Functional adaptations are internal processes, such as reduced sweating, concentrated urine or venom production. Because habitats differ in temperature, water, light and predators, the features that help in one place may be useless elsewhere. When explaining an adaptation, name the feature, state the challenge it addresses and link it to survival or reproduction, for example: streamlined shape reduces drag, so the organism escapes predators more easily.

What earns the marks

• Define adaptation as an inherited feature that increases an organism's chance of survival and reproduction in its normal habitat.
• Classify a named example correctly as structural, behavioural or functional, for example thick fur as structural, migration as behavioural and reduced sweating as functional.
• Link each adaptation to a specific selection pressure in the habitat, such as low temperature, scarce water, strong sunlight or predation.
• Explain the consequence of the adaptation for survival or reproduction rather than merely naming the feature.
• Compare organisms in different habitats to show that the same feature can be advantageous in one environment and disadvantageous in another.

Common mistakes and how to put them right

• Calling any feature an adaptation without linking it to survival or reproduction.

  Put it right by stating the benefit the feature gives in that habitat.

• Treating learned behaviour as a behavioural adaptation.

  Put it right by checking that the behaviour is inherited and typical of the species.

• Confusing functional with structural adaptations.

  Put it right by deciding whether the feature is a body part or an internal process such as water retention.

Exam tips

• Use the three labels structural, behavioural and functional explicitly when the question asks you to classify adaptations.
• Structure longer answers as feature, challenge and benefit so every clause of the statement is addressed.
• Choose examples from the habitat named in the question rather than repeating a standard polar bear or cactus answer.