Adaptations Flashcards
Adaptation
Characteristics that increase an organisms chance of survival and reproduction in its environment
Adaptations can be divided into 3 groups :
Anatomical adaptations
Behavioural adaptations
Physiological adaptations
Anatomical adaptations
Physical features internal and external
Behavioural adaptations
The way an organism acts these can be inherited or learnt from their parents
Physiological adaptations
Processes that take place inside an organism
Anatomical adaptations
Body covering
Camouflage
Teeth
Mimicry
Mimicry
- copying another animal’s appearance or sounds allows a harmless organism to fool predators into thinking it is poisonous or dangerous
Teeth
- the shape and type of teeth present in an animals jaw are related to its diet
- herbivores such as sheep have continuously growing molars for chewing tough grass and plants
- carnivores such as tigers have sharp large canines to kill prey and tear meat
Camouflage
- the outer colour of an animal allows it to blend into its environment making it harder for predators to spot it
- for eg. The snowshoe hare is white in winter to match the snow and turns brown in summer to blend in with the soil and rock environment in which it lives
Body covering
- animals have a number of different body coverings such as hair ,scales, spines,feathers and shells
- these can help the organism to fly such as feathers on birds - help it to stay warm such as thick hair on polar bears
- thick waxy layers on plants prevent water loss
- spikes can deter herbivores and protect the tissues from sun damage
Marram grass
- found on sand dunes around the UK
- it is a xerophyte
Adaptations of marram grass
Adaptations reduce the rate of transpiration and include:
- curled leaves to minimise the surface area of moist tissue exposed to the air and protect the leaves from the wind
- hairs on the inside surface of the leaves trap moist air close to the leaf reducing the diffusion gradient
- stomata sunk into pits which make them less likely to open and lose water
- a thick waxy cuticle on the leaves and stems reducing water loss through evaporation
Behavioural adaptations
Survival behaviours
Courtship
Seasonal behaviours
Migration
Hibernation
Hibernation
- a period of inactivity in which an animals body temperature, heart rate and breathing rate slow down to conserve energy
- reducing the animals requirement for food
- for eg, brown bears hibernate during the winter
Migration
Animals move from one region to another and then back again when environmental conditions are more favourable
This may be for a better climate or a source of food
Seasonal behaviours
These adaptations enable organisms to cope with changes in their environment
They include :
Migration
Hibernation
Courtship
Many animals exhibit elaborate courtship behaviours to attract a mate
For eg. Scorpions perform a dance to attract a partner
Thus increasing the organisms chance of reproducing
Survival behaviours
For eg. A opossum plays dead and a rabbit freezes when they think they have been seen
What two main categories do behavioural adaptations ?
Innate behaviour
Learned behaviour
Innate behaviour
- the ability to do this is inherited through genes
- for eg. The behaviour of spiders to build webs and wood lice to avoid light is innate
- this allows the organism to survive in the habitat in which it lives
Learned behaviour
- these adaptations are learnt from experience or from observing other animals
- an example of learned behaviour is the use of tools for eg. Sea otters use stones to hammer shells off rocks and then to crack the hard shells open
Physiological adaptations
Poison production
Antibiotic production
Water holding
Position production
Many reptiles produce venom to kill their prey and many plants produce poisons in their leaves to protect themselves from being eaten
Antibiotic production
Some bacteria produce antibodies to kill other species of bacteria in the surrounding area
Water holding
The water holding frog can store water in its body
This allows it to survive in the desert for more than a year without access to water
Many cacti and other desert plants can hold large amounts of water in their tissues
What do anatomical adaptations provide evidence for ?
Convergent evolution
Analogous structures
They have adapted to perform the same function but have different genetic origin
Convergent evolution
- when unrelated species begin to share similar traits
- these similarities evolve because the organisms adapt to similar environments or other selection pressures
- organisms live in a similar way to each other
Marsupials ( required example in ocr )
Marsupials and placental mammals are an example of convergent evolution
- Placental mammals a placenta connects the embryo to its others mothers circulatory system in the uterus
- this nourishes the embryo allowing it to reach a high level of maturity before birth
- marsupials also start life in the uterus but then leave and enter the marsupium while they are still embryos
- they complete their development here by sucking milk
Marsupial and placental mole
- both burrow throughout soft soil to find worms and grubs
- they have a streamlines body shape and modified forelimbs for digging
- velvety fur which allows smooth movement through the soil
- but they differ in fur colour - the marsupial mole ranges in colour from white to orange whereas the placental mole is grey
