transpiration🫧

Question 1

What is transpiration?

Answer 1

The diffusion of water vapour from leaf air spaces → atmosphere through stomata

Question 2

What drives transpiration?

Answer 2

A water-potential gradient between the leaf interior and the outside air

Question 3

Outline the three main steps of transpiration.

Answer 3

water diffusion from xylem to mesophyll cells, evaporation from mesophyll cell surfaces into intercellular spaces, and diffusion of water vapor out of the leaf through stomata

Question 4

How does transpiration assist water movement in plants?

Answer 4

It creates negative tension in the xylem, helping pull water from roots to leaves

Question 5

How does light intensity affect transpiration?

Answer 5

Higher light → stomata open wider → transpiration increases

Question 6

How does temperature affect transpiration?

Answer 6

Higher temperature → faster evaporation and diffusion → transpiration increases

Question 7

How does wind/air movement affect transpiration?

Answer 7

Wind removes saturated air near stomata → increases gradient → transpiration increases

Question 8

How does humidity affect transpiration?

Answer 8

Low humidity → steep gradient → transpiration increases; high humidity → transpiration decreases

Question 9

What happens when soil water is limited?

Answer 9

Reduced uptake → loss of turgor → stomata close → transpiration slows

Question 10

How do xerophytes adapt to reduce transpiration?

Answer 10

Leaf rolling, vertical orientation, sunken stomata, hairy leaves, thick cuticle, spines,
small leaves