plant adaptations Flashcards
what are plants that live in aquatic conditions called
Hydrophytes
what are plants that live in dry and arid conditions called
xerophytes
what must terrestrial plants be adapted to
-reduce the loss of water
-replace the water that is lost
what type of adaptations do most terrestrial plants reduce water losses by
-behavioural
-structural
what reduces water loss due to evaporation
waxy cuticle on leaf
-stops evaporation through epidermis
how are stomata adapted on terrestrial plants
-on the under surface of the leaf not on top
-reduces evaporation due to direct heating from sun
why do decidous plants loose their leaves
-when ground may be frozen (less water available)
-temp may be too low for photosynthesis
what is marram grass a type of and why
xerophyte
-because water in sand drains quickly and may be salty
how is the leaf of marram grass adapted
-rolled longitudinally so air is trapped inside becoming humid
-reduces water loss from leaf
-leaf can roll more tightly in very dry conditions
-thick waxy cuticle on outside of upper epidermis
how are stomata in maram grass adapted
-on the inner side of the rolled leaf so protected by enclosed air space
-in pits on the lower epidermis which is also folded and covered by hairs to reduce air movement and loss of water vapour
how is spongy mesophyll in maram grass adapted
-its dense with a few air spaces
-less surface area for evaporation of water
how are the spines on prickly pairs adapted
-protect it from predation which it is susceptable to as a source of water
-they reflect some light to lower internal temp of plant
-may trap a layer of air at the plants surface reducing evaporation
how is the epidermis of the prickly pair adapted
-covered in a waxy layer known as cuticle
-thicker than that of the average plant to reduce evaporation through the tissue surface
how are the stomata adapted in the prickly prickly pair
-mainly found on stem
-fewer number than most plants
-open at night rather than during the day to reduce water loss
-co2 absorbed is fixed for use during the day when photosynthesising
how is the stem of the prickly pair adapted
-where majority of photosynthesis occurs
-forms thick fleshy pads adapted for efficient water storage
-channels of pale mucilage cells hold additional water
how are xerophytic stomata adapted to low water availability
-closed stomata when water availability is low so reduces water loss so reduces how much water they need to uptake
how does a low water potential in the leaf occur and how is it beneficial to xerophytic plants
-achieved by maintining high salt concentration in the cells
-reduces the evaporation of water from cell surface
-as water potential gradient between cells and air space is reduces
how do hydrophytes tanspire
through specialised structures at the tip/ margins of leaves called hydathodes
what are hydathodes
-structures that can release water droplets which may then evaporate from leaf surface
what issues may hydrophytes have
-getting o2 to submerged tissues
-keeping afloat so that leaves are in sunlight for photosynthesis
how is the water lilly adapted
-many large air spaces in leaf to keep it afloat so they can absorb sunlight
-stomata on upper epedermis so exposed to air to allow for gas exchange
how is the leaf stem of water lilly adapted
-has many large air spaces
-helps w bouyancy
-helps o2 diffuse quickly to roots for aerobic respiration
