STRUCTURAL ADAPTATIONS FOR ANIMALS
The following adaptations allow animals to cope with abiotic factors, such as temperature and water
availability, and biotic factors, such as predators, prey and competition.
Thick fur and blubber to insulate against the cold
Bright features to help attract mates
Large ears to increase heat loss
Webbed feet or flippers for swimming
Spines for protection
Overall body shape and size to conserve body heat or water
Patterned body for camouflage
Surface area to Volume Ratio
A larger surface area to volume ratio means that a small animal can cool down and heat
up much more quickly (suited to hot dry climates). A larger animal of the same shape
will have a greater volume to its surface area, meaning it can more effectively conserve
body heat (suited to cold environments)
PHYSIOLOGICAL ADAPTATIONS OF PLANTS
Crassulacean acid metabolism (CAM) – reduces water loss in plants. In CAM plants, the
stomata open only at night to collect carbon dioxide and stores it as a product called
malic acid. During the day the malic acid is transported to the chloroplasts where the
carbon dioxide is used in photosynthesis
Discuss how mangroves survive in high salinity conditions
Mangroves are able to survive in high salinity conditions through the physiological processes of salt
excretion, exclusion and accumulation. Saltwater can kill plants, so mangroves must extract
freshwater from the saltwater through the process of salt exclusion. Roots exclude salt molecules1
They do this by filtering out the salt as it enters the roots of the plant. Another process adapted by
mangrove plants to survive high salinity conditions is through salt excretion. This means that
saltwater is excreted through glands in the leaves. Finally, a third strategy utilised by mangrove
species is salt accumulation. Acculate the salt in their leaves, lose leaves when it gets too much salt
Mangroves survive by getting freshwater, oxygen and reproducing
Some plants are frost tolerant. Explain how antifreeze proteins reduce cellular damage
PHYSIOLOGICAL ADAPTATIONS OF ANIMALS
Producing concentrated urine to conserve water in desert animals e.g. spinifex, hopping
mouse
Producing venom for capturing prey or defence e.g. snakes, spiders, wasps, platypus
Changing colour to aid in thermoregulation e.g. chameleons
Shivering to maintain body temperature
Counter current- Heat exchange for heating
This occurs in animals living in extremely cold climates, to reduce heat loss and maintain
body temperature
Penguin extremities have a large surface area and lose heat when exposed to the cold.
Warm blood in the arteries (travelling towards flippers) transfers heat to the veins (travelling
back to heart). This reduces heat loss
Evaporative Cooling
Animals that live in hot environments need physiological adaptations to efficiently
exchange heat with their environment and keep their internal organs at a stable
condition
When warm sweat comes into contact with cooler air, it evaporates, carrying heat away
and lowering body temperature
BEHAVIOURAL ADAPTATIONS FOR PLANTS
Plants move in response to positive and negative conditions in their environment
The mechanism for plant movement are controlled by hormones or turgor pressures. Rapid
plant movement relies on turgor pressure. When a plant cell takes in water through osmotic
regulation, it cannot expand, due to the rigid cell wall. This increases the internal pressure of
the cell, and is referred to as turgor pressure
Tropism
A ‘tropism’ is a growth in response to a stimulus. Plants grow towards soruces of water and
light, which they need to survive and grow
Auxin is a plant hormone produced in the stem tips and roots, which controls the direction
of growth. In darkness, elongation of cells spread evenly down both sides of the stem, but
the presence of light effects the auxins. When the light is on one side of the seedlings, the
auxins become concentrated on the dark side and causes the cells on the light side to not
elongate and bend towards the light.
BEHAVIOURAL ADAPTATIONS FOR ANIMALS
Animals have many behavioural adaptations to respond to changes in their environment
- Seeking or leaving shade of shelter
- Huddling to maintain body temperature
- Burrowing and migration
Questions:
1. Choose an animal that migrates regularly. Briefly describe the scale and purpose of the
migration, and explain how this is advantageous
2. Analyse the following statement “although humans take a physiological approach to
evaporative cooling, animals employ a behavioural approach instead’.
Acquired characteristics cannot be changed
Survival of the Fittest- the one that can survive current selection pressures
