Variation , adaption , natural selection and speciiation Flashcards
Define variation
Difference between cells, individual organisms, or groups of organisms of any species
Define intra-specific variation
These are differences between individuals within the same species.
Examples of Intra-specific variation ?
Skin colour , Hair colour , height , intelligence etc
Define inter - specific variation
These are differences between different species of organisms
Examples of Inter - specific variation ?
Warm blooded , cold blooded , bone structure
Define discontinuous variation
These are discrete traits / characteristics
Examples of discontinuous variation
Tongue roller
Blood types
eye colour
Define continuous variation
A trait / characteristics where they exist within a range , not discrete values
Examples of continuous variation
Weight , human birth weight and height
Define genetic variation / inherited variation
This is variation which is carried in your DNA , usally inherited by your parents
Define environmental variation
These are characteristics which arise due to your environment eg how much you eat or exercise
Example of environmental variation ?
Skin tone / complexion - there is a genetic component within your DNA but alos your exposure to UV light / sunlight also affects skin tone
What are the Dangers associated with sun tanning ?
Melanoma - skin cancer
less elastic skin
How can you protect your skin from the UV light ?
Sun block
Define adaptation
When an organisms characteristics change to make it more likely to survive in a specific environment
Examples of why species need to adapt
To avoid predators or catch prey
To counteract environment changes eg sunlight
Define behavioural adaptions
Changes in behaviour to deal with change
Example of behavioural change in animals ?
Meerkats in response to predators
Define physiological / biochemical adaptions
Changes to their bodies to deal with a challenge eg angler fish use lights to attract prey
Define anatomical adaptations
Features within their bodies which made them more likely to survive eg dolphins , bats
Define xerophytes
Plant adapted to the extreme conditions eg dry , windy conditions
Example of a xerophytes
Thick fleshy stem to store water
Describe natural selection
In every generation of a species there are more off spring then needed
Some have favourable features and some not
Those favourable features are more likely to survive , breed and pass on their traits , so eventually most will have favourable traits
What features of organisms cause natural selection to arise
More off spring than needed
Random changes to DNA
DNA can be inherited by future generations
What are selection pressures ?
These are environmental factors which cause natural selection to occur
Example of selection pressures
Climate change , predators , diseases , food availability
