B2e

Question 1

Equation for surface are to volume ratio, and what does this mean

Answer 1

Ratio = surface area / volume

Organisms with a large ratio, may lose more heat and water

Question 2

How has the brown Alaskan bear adapted to catch salmon

Answer 2

• 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

Question 3

How has salmon adapted to escape bears

Answer 3

• 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

Question 4

What are examples of other defence mechanisms

Answer 4

• 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)

Question 5

Examples of adaptations a polar bear has for surviving in the cold

Answer 5

• 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

Question 6

What is a specialist

Answer 6

An organism that is only suited to one type of habitat

Question 7

What is a generalist

Answer 7

An organism that can survive in different habitats and conditions

Question 8

What does a counter current heat exchange in penguins mean

Answer 8

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

Question 9

What do some plants have, that means they can survive in extreme cold

Answer 9

Antifreeze proteins

Question 10

Examples of behavioural adaptations that help some organisms survive

Answer 10

• 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

Question 11

How have cacti adapted to survive in dry conditions

Answer 11

• 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