Adaptations (AQA GCSE Biology: Combined Science)

• 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:

Types of adaptation to the environment table

Adaptations to the cold regions

• Animals here often have a small surface area : volume ratio to minimise heat loss to their surroundings (rounded shape of penguins/seals, small ears of the Arctic fox)
• A thick layer of fat (seal blubber) or fur (polar bears) insulates against the cold
• These are examples of structural adaptations

Adaptations to desert regions

• Some desert animals have specially adapted kidneys which produce very concentrated urine, helping the animal to retain water – this is a functional adaptation
• Some are only active in the early mornings, late evenings or at night when it is cooler – this is a behavioural adaptation
• Some animals have structures to increase their surface area : volume ratio to aid heat loss (large ears of African elephants) – these are structural adaptations

A cactus has many structural adaptations to help it survive in the desert

• Some organisms live in environments that are very extreme, such as at very high or low temperatures, pressures, or high salt concentration
• Organisms that can live in extreme environments are called extremophiles
• An example of habitats where extremophiles are found are deep-sea volcanic vents, where the conditions are extremely hot, under high pressure and there is no sunlight
• Bacteria called chemoautotrophs survive by using inorganic chemicals to obtain energy (rather than using sunlight in photosynthesis as photoautotrophs do)
• Other species can then use the bacteria as a source of nutrition – the bacteria are producers in these food chains