external factors affecting rate of transpiration

Question 1

what are the external factors

Answer 1

• light intensity
• humidity
• air movement
• soil water availability
• temperature

Question 2

light intensity

Answer 2

• rate of transpiration is higher is day time due to there being more light (photosynthesis)
• rate is less at night-time as its dark and often the stomata close over when theres no light available
• to reduce excess water loss

Question 3

humidity

Answer 3

• if the surrounding air around the leaf is humid, the slower the rate of transpiration happens
• this is because humidity has more water potential than normal air
• humidity decreases a water potential gradient between the leaf and outside (equilibrium)
• results in no net movement of water outside of the leaf

Question 4

water soil availability

Answer 4

if soil is moist- more water availability- higher rate of transpiration
if soil is dry- less water availability- slower rate of transpiration

Question 5

temperature

Answer 5

higher temperature- increased rate of diffusion
- water molecules have more kinetic energy
- evaporates faster fro the mesophyll cells
- out the stomata

high temperatures can cause stress or wilting

Question 6

air movement

Answer 6

faster rate of air movement- faster rate of transpiration
- faster movement maintains a steep concentration gradient for the water molecules to evaporate through
- fast air movement quickly removes humid air from surroundings to create a continous flow