CB6 Plant Transport

Question 1

What is the function of root hair cells?

Answer 1

Absorb water and mineral ions from the soil.

Question 2

What 3 specialisations do root hair cells have?

Answer 2

Many mitochondria, large permanent vacuole, hair-like extension

Question 3

What is the function of xylem vessels?

Answer 3

Transport water and mineral ions up the plant.

Question 4

What 3 specialisations do xylem vessels have?

Answer 4

Lignified cell walls (strengthened with lignin) ,dead cells, no end cell walls,

Question 5

What is the function of phloem vessels?

Answer 5

Transport sugar in the plant to where it is required.

Question 6

What 2 cells make up phloem vessels?

Answer 6

Sieve tube cells, companion cells

Question 7

What 3 specialisations do sieve tube cells have?

Answer 7

Little cytoplasm / few organellese, sieve plates, pores to allow substances through the ends

Question 8

What 3 specialisations do companion cells have?

Answer 8

Many mitochondria, large nucleus, pores

Question 9

What is transpiration?

Answer 9

The evaporation and diffusion of water from inside the plant to outside.

Question 10

What does transpiration occur through?

Answer 10

Stomata

Question 11

What cells surround the stomata?

Answer 11

Guard cells

Question 12

What 3 gases are exchanged through the stomata?

Answer 12

oxygen, carbon dioxide, water vapour

Question 13

What happens to the guard cells in order to open the stomata?

Answer 13

Water diffuses in by osmosis causing the guard cells to become turgid.

Question 14

What happens to the guard cells in order to close the stomata?

Answer 14

Water diffuses out by osmosis causing the guard cells to become flaccid.

Question 15

What is the transpiration stream?

Answer 15

The flow of water from the soil into the roots, up the xylem, out of the leaves into the atmosphere.

Question 16

What 4 environmental conditions affect the rate of transpiration?

Answer 16

light intensity, temperature, air movement, humidity

Question 17

What is the effect of increasing humidity on the rate of transpiration?

Answer 17

Decreases

Question 18

What 2 environmental conditions affect the water vapour concentration gradient between the leaf and atmosphere?

Answer 18

humidity, air movement

Question 19

What environmental condition affects whether the stomata are open or closed?

Answer 19

light intensity

Question 20

What 3 specialisations are found in most plants to reduce water loss?

Answer 20

waxy cuticle, stomata on underside of leaf, wilting

Question 21

What is measured using a potometer?

Answer 21

Rate of water uptake / transpiration in a plant.

Question 22

What are appropriate units to use for calculating the rate of transpiration using a potometer?

Answer 22

mm / min

Question 23

What are 3 uses of water in a plant?

Answer 23

Photosynthesis, transport, keeping plant upright

Question 24

What is glucose converted into for it to be transported in a plant?

Answer 24

Sucrose

Question 25

What process transports sucrose through the phloem vessels?

Answer 25

Translocation (it requires energy from respiration)

Question 26

What is a source in a plant?

Answer 26

A part of the plant that produces sugars.

Question 27

What is a sink in a plant?

Answer 27

A part of the plant that requires sugars and cannot produce it themselves.

Question 28

Where is the source in a plant during the summer?

Answer 28

Leaves

Question 29

Where is the source in a plant during the spring?

Answer 29

Roots

Question 30

Where is the sink in a plant during the summer?

Answer 30

Roots

Question 31

Where is the sink in a plant during the spring?

Answer 31

Growing leaves

Question 32

What are sugars stored as in the roots?

Answer 32

Starch

Question 33

What process loads sucrose into the phloem vessels at the source?

Answer 33

Active transport

Question 34

What process unloads sucrose from the phloem vessels at the sink?

Answer 34

Diffusion

Question 35

What causes sucrose to flow in the phloem vessels from the source to the sink?

Answer 35

Difference in pressure / pressure gradient