Adaptations (AQA GCSE Biology: Combined Science)

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Adaptations to the Environment

  • 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

Types of adaptation to the environment table, IGCSE & GCSE Biology revision notes

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

 

Structural adaptations of a cactus, IGCSE & GCSE Biology revision notes

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

Extreme Adaptations

  • 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

Examiner Tip

Make sure you understand the concept of surface area : volume ratios and why they are important when it comes to how animals are adapted to cold or hot environments, as this is a tricky concept that often comes up in exams.A small surface area : volume ratio means that the animal has a small surface area compared to its volume. This helps to reduce heat loss. A large surface area : volume ratio means that the animal has a large surface area compared to its volume. This helps to increase heat loss.Generally, the larger the animal, the smaller its surface area : volume ratio.

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Lára

Author: Lára

Expertise: Biology Lead

Lára graduated from Oxford University in Biological Sciences and has now been a science tutor working in the UK for several years. Lára has a particular interest in the area of infectious disease and epidemiology, and enjoys creating original educational materials that develop confidence and facilitate learning.