Mass Transport (plants)

Question 1

What is transpiration

Answer 1

Transpiration is the evaporation of water through the stomata, typically on leaves.

Question 2

What impacts the rate of transpiration

Answer 2

If the surrounding air is less humid

or there is a lot of wind to carry away evaporating water molecules,

then transpiration will occur faster due to a greater concentration gradient.

Question 3

What impacts the rate of transpiration

Answer 3

If the surrounding air is less humid

or there is a lot of wind to carry away evaporating water molecules,

then transpiration will occur faster due to a greater concentration gradient.

Question 4

How do guard cells control water loss from plant

Answer 4

Guard cells swell and bend when the plant has a lot of water, resulting in the stomata opening.

Question 5

Describe cohesion

Answer 5

Due to the dipolar nature of water, it forms hydrogen bonds between water molecules, creating cohesion. This cohesion results in water forming a continuous column in the plant

Tension is created when the water evaporates out of the stomata.

Question 6

Describe cohesion tension theory

Answer 6

1.water lost from evaporation
2.lowers water potential of mesophyll cells
3.water pulled up creating tension
4. Water molecules stick together by hydrogen bonds (cohesion)
5.forming continuous water column
6.adhesion of water to walls of xylem

Question 7

How do you figure out rate of transpiration

Answer 7

Using potameter experiment

Water drawn up from roots =rate of transpiration

the distance the bubble moved can be used to work out the volume of water in the tube that evaporated. This volume is divided by the time it took to lose that volume of water to get a rate

Question 8

How do you figure out rate of transpiration

Answer 8

Using potameter experiment

Water drawn up from roots =rate of transpiration

the distance the bubble moved can be used to work out the volume of water in the tube that evaporated. This volume is divided by the time it took to lose that volume of water to get a rate

Question 9

What is phloem tissue

Answer 9

Phloem tissue consists of living sieve tube elements that each have a companion cell. Sieve tube elements

Question 10

What does the phloem do

Answer 10

Phloem tissue transports organic substances in plants. These organic substances include sugars, such as sucrose, and some mineral ions, which travel as the dissolved form of sap.

Question 11

Define translocation

Answer 11

Sucrose travels as the dissolved form of sap. They go to storage organs and growing areas of the plant.

Question 12

Describe the mass flow hypothesis

Answer 12

1.) In leaves glucose is actively transported into phloem
2.)By companion cells
3.)Lowers water potential in sieve cells and water enters by osmosis
4.)Increase in pressure causes mass movement
5.)Sugars used for respiration

Question 13

What is ringing experiments used for

Answer 13

Ringing experiments can be used to find out whether it is the phloem, xylem, or both that is responsible for the translocation of sugars in plants.

Question 14

What is ringing experiments used for

Answer 14

Ringing experiments can be used to find out whether it is the phloem, xylem, or both that is responsible for the translocation of sugars in plants.

Question 15

What is ringing experiments used for

Answer 15

Ringing experiments can be used to find out whether it is the phloem, xylem, or both that is responsible for the translocation of sugars in plants.