plant adaptation for water avaliability

Question 1

types of plants

Answer 1

xerophytes , dry conditions, cactus + marram grass
mesophytes
hydrophytes , water plants

Question 2

adaptations of hydrphytes

Answer 2

thin/no waxy cuticle, no need to conserve water bc live in water

open stomata on upper surface (in contact with air) ,maximise gaseous exchange, no risk of loss of turgor, abundance of water available, open stomata all the time

reduced structure to plant, water support leaves + flowers, no need for strong supporting structures

wide and flat leaves, spread across water, capture as much light as possible

Question 3

examples of hydrophytes

Answer 3

water lilies
watercress

Question 4

problems with hydrophytes

Answer 4

water logging, air space need to be full of air not water

Question 5

adaptations of xerophytes

Answer 5

thick waxy cuticle, minimise water loss, help survive hot summers + cold winters

sunken stomata in pits, reduce air movement, produce microclimate of still, humid air, lower water vapour gradient, less transpiration

reduced number of stomata, reduce water loss by transpiration, reduce gas exchange

hairy leaves, create microclimate of still and humid air, lower water vapour gradient, reduce transpiration

reduced leaves, reduce leaf area, reduce water loss, small SA:V

curled leaves, reduce water loss

succulents, store water in specialised parenchyma, sufficient supply, used in times of drought

leaf loss, lose leaf when water not available

Question 6

marram grass

Answer 6

xerophytes
lives on sand dunes
water drains away quickly, salty sand
rolled leaves, air trapped inside + become humid, reduce evaporation
thick waxy cuticle
stomata on inner side
stomata in pits, folded, covered by hairs, reduce air movement + loss of water vapour
dense spongy mesophyll w few air space, less SA for evaporation

Question 7

cactus

Answer 7

succulents, store water in stems, fleshy + swollen, expand when water available

leaves reduced to spines, reduced SA

widespread roots

close stomata when water availability low

low water potential inside leaf cell, maintain high salt concentration in cell, reduce water evaporation

Question 8

water lily

Answer 8

many large air spaces, keep afloat, absorb light

stomata on upper epidermis, exposed to air for gaseous exchange

leaf/stem has many large air space, help with buoyancy, allow oxygen to diffuse quickly to roots for aerobic res

contain hydathodes at leaves tips, release water droplets, evaporate from leaf surface maintain transpiration stream