9.5 Plant adaptions to water availability

Question 1

Xerophytes

Answer 1

plants that are adapted to survive in dry habits

Question 2

Examples of xerophytes

Answer 2

cacti, conifers and marram grass

Question 3

Methods of water conservation for xerophytes

Answer 3

thick waxy cuticle: helps minimise water loss

Sunken stomata: located in pits to reduce air movement ( creates microclimate of humid air)

Reduced number of stomata: reduce water loss by transpiration

Reduced leaves: reduce area for water loss to occur

Hairy leaves: microclimate of still humid air= reduced water vapour potential gradient

Curled leaves: confines all stomata within microenvironment

Succulents: store water in specialised parenchyma

Leaf loss

Question 4

How are the roots of xerophytes adapted to minimise water loss?

Answer 4

long tap roots growing deep into teh ground= access to water deep underground

widespread shallow roots with large SA

Question 5

Hydrophytes

Answer 5

plants that live on water

Question 6

Adaptions of hydrophytes

Answer 6

very thin/ no waxy cuticle

many open stomata on the upper surfaces: maximising water loss

Reduced structure to plant

wide, flat leaves (more surface across water to capture light)

small roots

large SA of stem and roots

air sacs to float

arenchyma

Question 7

what is arenchyma

Answer 7

specialised parenchyma tissue forming in leaves, stem and roots
–> many large air sacs