Some animals are adapted to live in cold conditions, for example, Polar Bears.
They keep warm by reducing heat loss.
Anatomical adaptations- How an animal/plants body is structured to either reduce heat loss, or to increase heat loss.
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Adapting to the Cold 2
Animals have- excellent insulation- this cuts down heat loss, e.g. Arctic fox: thick fur to trap air for insulation. Seals: thin fur but thick layer of fat under skin.
These animals are usually quite large and have small ears- this decreases heat loss and surface area to volume ratio.
Animals may avoid the cold by changing their behaviour.
Some travel long distances to warmer areas.
Some hibernate (this slows down their body processes)
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Adapting to the Cold 3
Penguins have counter-current heat exchange to help reduce heat loss.
Counter-current- The warm blood heats up a colder part of the body, for example in Penguins, the warm blood enters the flippers, warms up the cold blood leaving, to stop it cooling the Penguins' body.
Other organisms that live in cold climates may have biochemical adaptaions, such as antifreeze proteins in their cells.
Biochemical- invloving chemical processes in living organisms.
Antifreeze protein- produced by a specialised adaptaion like certain fish, insect, plant or bacteria.
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Adapting to hot, dry conditions
Oragnisms like cactus and cacti live in very hot, dry conditions.
These animals need to increase heat loss. To do this, they adapt in a variety of ways:
Having very little hair on the underside of their body
They are usually smaller but have larger ears than animals that live in a cold environment. This gives them a larger surface area to volume ratio, so they can lose more heat.
They pant and lick their fur, which is behavioural (they choose to do it).
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Adapting to hot, dry conditions 2
To reduce heat gain (keep cool), animals can change their behaviour, for example they search for shade during hotter hours.
To cope with dry conditions, organisms have behavioural, anatomical and physiological adaptations, for example:
Camals are able to survive with little water because they produce very concentrated urine.
Cacti reduce water loss because their leaves have reduced to spines. They have deep roots and store water in the stem.
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Adapting to hot, dry conditions 3
Extremophiles- Organisms that can survive in hot conditions.
Some bacteria can live in hot springs as they have enzymes that do not denature at temperatures as high as 100°C.
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Specialists or Generalists
Some organisms, e.g. Polar Bears, are called specialists, as they are very well adapted to living in their habitat. They would struggle to live somewhere else.
Other organisms, e.g. rats, can live in many habitats.
They are called generalists.
They will lose to the specialists in certain habitats.
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