Equation for surface are to volume ratio, and what does this mean
Ratio = surface area / volume
Organisms with a large ratio, may lose more heat and water
How has the brown Alaskan bear adapted to catch salmon
- the bear has eyes at the front of its head which helps it judge distance and size
- the bear has developed hunting skills, so it knows when the salmon will be in the river
- they time their breeding, so that cubs are born when the salmon population increases - this is synchronous breeding
How has salmon adapted to escape bears
- streamlined shape to help it swim fast
- swim in groups, so that an individual’s chances of escaping are greater
- have eyes on the side of their head to give them a wide field of view - a wider chance of seeing the bear
What are examples of other defence mechanisms
- poisonous
- have stings
- mimic warning colouration of wasps so animals think they have stings
- coloured/patterned to blend in with surroundings so they can hide (cryptic colouration)
Examples of adaptations a polar bear has for surviving in the cold
- thick fur and blubber for insulation
- large volume to surface area ratio, to stop losing too much heat
- small ears, to reduce surface area to which heat can be lost
What is a specialist
An organism that is only suited to one type of habitat
What is a generalist
An organism that can survive in different habitats and conditions
What does a counter current heat exchange in penguins mean
The warm blood entering its flippers flows past cold blood leaving its flippers. This warms the cold blood, and cools the warm blood, and so reduces heat loss from the flippers
What do some plants have, that means they can survive in extreme cold
Antifreeze proteins
Examples of behavioural adaptations that help some organisms survive
- hibernate over winter when food is scarce
- migrate to warmer countries that have more food in the winter
- reptiles can’t regulate their body temperature, so they sit in or out the sun to warm up or cool down
How have cacti adapted to survive in dry conditions
- very long roots to reach as much water as possible
- covered with a thick waterproof cuticle to reduce water loss
- water is stored in a fleshy stem
- spines reduce water loss and stop animals getting at the water in the stem
- the round shapes reduces surface area, and therefore reduced water loss through evaporation
