transpiration

Question 1

what is the difference between transpiration and translocation?

Answer 1

transpiration is evaporation of water from surface of a plant
translocation is movement of food through phloem tube

Question 2

describe the process of transpiration?

Answer 2

water evaporates from cells inside the leaf
water vapour diffuses through air spaces in spongy mesophyll and out of leaf through stomata
water passes through xylem to leaf to replace water that has been lost
water is drawn into root hair cells and up the xylem tubes to leaf

Question 3

how does temperature affect rate of transpiration?

Answer 3

higher temp higher rate
particles have more kinetic energy to diffuse in and out of plant

Question 4

how does humidity affect rate of transpiration?

Answer 4

higher rate under drier conditions, when air isnt humid
because evaporation is faster under drier conditions

Question 5

how does windy conditions affect rate of transpiration?

Answer 5

faster rate in windy conditions
wind removes any water vapour, allowing more water to evaporate

Question 6

how does light intensity affect rate of transpiration?

Answer 6

high rate more light intensity
high light intensity increases rate of photosynthesis
stomata also opens and allows co2 in and water vapour out

Question 7

how do stomata work?

Answer 7

surrounded by 2 guard cells
when light intensity is high e.g. during day, guard cells swell and change shape, causing stomata to open and allow co2 in for photosynthesis
under hot conditions, stomata closes to reduce water loss by transpiration, which means plant cant photosynthesise