adaptations to water

Question 1

kinds of adaptations

Answer 1

surviving in saturated soil

recieving low light

getting low C02 and 02

accesssing nutriants (if free-floating)

water retention and mineral uptake in salt environments

Question 2

adaptations for low oxygen

Answer 2

Internal gas transport

• aerenchyma
• hypertrophy

Adventitious roots

Pneumatophores

Prop roots

Rapid shoot extension

Stem buoyancy

Question 3

too much water

Answer 3

when roots lack oxygen, water uptake is limited

ironically the wilt

stomata close

photosynthesis drops

Anaerobic respiration replaces aerobic

cellular acidosis

Question 4

Aerenchyma formation stimulated by…

Answer 4

ethylene

(cause either lysigeny or schizogeny)

Question 5

adventitious roots

Answer 5

those that arise from places other than the root

Question 6

“knees”

Answer 6

pnuematophores

Question 7

2 benefits of floating leaves (propped up by aerenchyma)

Answer 7

acces to oxygen and carbon dioxide as well as light

Question 8

2 types of gas transport

Answer 8

passive diffusion (higher to lower concentration)

Pressurized ventilation (air enters through young leaves, moves to underground parts, then passes out of older leaves)

Question 9

plants adapted for high salinity are called…

Answer 9

halophytes

Question 10

ways halophytes aquire water and avoid excess build-up of salts

Answer 10

osmo-regulation via NaCl and compatible solutes

salt exclusion (filtration)

salt excretion via “salt glands”

Succulence –more water per volume dilutes salt effects

Question 11

adaptation to limited nutrients is most important when …

Answer 11

decomposition is slow

Question 12

three major adaptations to limited nutrients

Answer 12

mychorrhizae (important for phosphorus)

nitrogen fixation (via n-fixing bacteria)

carnivory

Question 13

adaptations to low light (submersed plants)

Answer 13

chloroplasts concentrated in epidermis

cuticle thin,

use of bicarbonate for photosynthesis

aquatic acid metabolism