- 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
- 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
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.