Bio Topic 7

Question 1

What do xylem vessels transport?

Answer 1

Water and minerals.

Question 2

What do phloem vessels transport?

Answer 2

Sucrose and amino acids.

Question 3

In which direction is water transported in a plant?

Answer 3

From roots to leaf.

Question 4

In which direction are sucrose and amino acids transported in a plant?

Answer 4

From source to sink.

Question 5

Which plant transport vessel transports sucrose and amino acids?

Answer 5

Phloem.

Question 6

Which plant transport vessel carries water and minerals?

Answer 6

Xylem

Question 7

What is a source?

Answer 7

Area of Production

Question 8

What is a sink?

Answer 8

The place of need (e.g. storage, use)

Question 9

What is the most common source of sucrose for a plant in summer?

Answer 9

Leaves

Question 10

What is the most common source of sucrose for a plant in winter?

Answer 10

The plant’s roots.

Question 11

Define transpiration.

Answer 11

The movement of water and minerals from the roots to the leaf (diffuse out through stomata).

Question 12

Define translocation

Answer 12

The movement of sucrose and amino acids from source to sink in the phloem vessel.

Question 13

What is the name of the process by which sucrose and amino acids are transported from source to sink in the phloem?

Answer 13

Translocation.

Question 14

What is the name of the process by which water and minerals are transported from roots to leaves in xylem?

Answer 14

Transpiration.

Question 15

What is the function of a root hair cell?

Answer 15

To absorb water and ions.

Question 16

What is the name of the plant cell that absorbs water from the soil?

Answer 16

Root hair cell.

Question 17

Why do root hair cells have a large surface area?

Answer 17

To increase rate of absorption of water and ions.

Question 18

What enables root hair cells to increase the rate of absorption of water and ions?

Answer 18

Large surface area

Question 19

Why do root hair cells have no chloroplasts?

Answer 19

They are underground, thus does not receive sunlight, meaning no need of chloroplast.

Question 20

Which structure usually found in plant cells is absent from a root hair cell?

Answer 20

Chloroplasts.

Question 21

Name the four tissues in a plant root, working from the outside inwards.

Answer 21

Root hair, Root cortex, Phloem, Xylem.

Question 22

What is the first cell a water molecule enters, when it is absorbed by a plant?

Answer 22

Root hair cell

Question 23

After leaving the root hair cell, through which tissue does water travel to get to the xylem vessels?

Answer 23

Root cortex.

Question 24

After leaving the xylem vessels, through which part of a leaf does water travel?

Answer 24

spongy mesophyll.

Question 25

Through which part of the lower epidermis does water evaporate from a leaf?

Answer 25

Stomata

Question 26

Name the four factors that affect the rate of transpiration.

Answer 26

Temperature, humidity, light intensity, wind speed

Question 27

Describe how increasing humidity affects the rate of transpiration.

Answer 27

Decreases water potential gradient, hence rate of osmosis is decreased.

Question 28

Describe how increasing temperature affects the rate of transpiration.

Answer 28

Temperature increase => transpiration rate increase

Question 29

Describe how increasing light intensity affects the rate of transpiration.

Answer 29

a

Question 30

Describe how increasing air movement affects the rate of transpiration.

Answer 30

Increased air movement => increased rate of transpiration

Question 31

Explain why increasing humidity decreases the rate of transpiration, using the term ‘concentration gradient’.

Answer 31

Humidity decreases the concentration of water molecules between the atmosphere and inside the leaf, decreasing the rate of transpiration.

Question 32

Explain why increasing temperature increases the rate of transpiration.

Answer 32

Increasing temperature increases the rate of evaporation as more water particles with higher energy escape the upper epidermis's surface.

Question 33

Explain why increasing light intensity increases the rate of transpiration.

Answer 33

a

Question 34

Explain why increasing air movement increases the rate of transpiration using the term ‘concentration gradient’

Answer 34

More air movement = removal of more water vapor => allows more water to diffuse out of plant and thus increasing the concentration gradient.

Question 35

Describe how xylem and phloem are arranged in the root of a plant.

Answer 35

Xylem in a 'X' shape at the center. | Phloem in a circle around the xylem.

Question 36

Describe how xylem and phloem are arranged in the stem of a plant.

Answer 36

In vascular bundles

Question 37

Describe how xylem and phloem are arranged in the leaves of a plant.

Answer 37

a

Question 38

What is a vascular bundle?

Answer 38

a

Question 39

Which parts of a plant contain vascular bundles?

Answer 39

Stem

Question 40

What is cohesion?

Answer 40

Cohesion refers to the attraction of water particles to other water particles.

Question 41

What is the name of the forces that cause water molecules to stick together?

Answer 41

Cohesion

Question 42

How does cohesion allow transpiration to occur?

Answer 42

a

Question 43

How can water loss from leaves be measured?

Answer 43

The percentage change in mass.

Question 44

What can be measured by the percentage change in mass of a leaf?

Answer 44

The rate of transpiration (loss of water)