adpatation Flashcards
(26 cards)
define adaptation
- a characteristic that enhances chances survival in the habitat
what is the purpose of adaptation ?
- help organism cope with environmental stresses
- obtain the things they need to survive
what would a well adapted organism be able to ?
- find enough food or photosynthesize well
- find enough water
- gather enough nutrients
- defend itself from predators and diseases
- survive the physical conditions of its environment , such as changes in temperature , light and water availability
- respond to changes in its environment
- have sufficient energy to allow successful reproduction
what are different ways adaptations can occur ?
- anatomical , behavioral or physiological
what is marram grass ?
- a very specialised plant
where is marram grass adapted to live ?
- living on sand dunes where there is little water available
what must marram grass be adapted to do ?
- take up as much water as possible and to avoid losing that water
what type of plant is marram grass ?
- xerophyte
define anatomical adaptations
- structural features
what does anatomical mean ?
- any structure that enhances the survival of the organism is an adaptations
give 5 examples of anatomical adaptations
- long roots –> enables the plant to reach water that is deep underground
- roots also spread out over a wide area –> enables marram to absorb a lot of water when it’s available it also helps to stablise sand dune in which the plant lives
- low density of stomata –> fewer stomata means that less water vapour is lost
- leaf covered in a thick waxy cuticle –> this reduces evaporation o water from the cells of the leaf
- lower epidermis is covered in hairs –> this reduces air movement so that water vapour is retained close to the lower epidermis
define behavioural adaptations
- the ways that behaviour is modified for survival
what is a behavioural adaptation ?
an aspect the behaviour of an organism that helps it to survive the conditions it lives in
what is an example of behavioural adaptation ?
- when touching an earthworm
–> it quickly contracts and withdraws into its burrow
why does the earthworm react in this way ?
- as it has no eyes , so it can’t tell whether your a bird about to eat it or not
–> it’s rapid withdrawal is a behavioural adaptation to avoid being eaten
what is an example of marram grass with behavioural adaptations ?
- marram grass responds to shortage of water by rolling leaf more tightly and closing the stomata
how is the marram grass behavioural adaptation beneficial ?
- both charges help to reduce transpiration
–> when covered by sand - marram will grow more quickly to reach the sunlight
define physiological adaptation
- affect the way that processes work
what is physiological adaptation ?
- one that ensures the correct functioning of cell processes
what is an example of physiological adaptation ?
- the yeast –> saccharomyces - can respire sugars aerobically or anaerobically depending on how much oxygen is available
what is 3 examples of physiological adaptations of marram grass ?
- the guard cells work in a similar way to open and close the stomata
–> non-turgid cells close the stomata and turgid cells open the stomata - marram is not very salt tolerant , but it maintains a cell water potential that is lower than other plants
–> enables it to survive in salty conditions found beside the sea - the leaves contain many lignified cells that provide support when turgidity is lost
–> this keeps the leaf upright when the water isn’t available
what 2 animals are from seperate evolution and are unrelated ?
- marsupial and placental moles
–> share a number of characteristics and look remarkably similar
what characteristics do the moles share ?
- cylindrical body
- small eyes
- strong front legs
- large claws on front legs
- short fur
- short tail
- nose with tough skin for protection
what is convergent evolution ?
when 2 species evolve similar characteristics independently of one another
