Transport and coordination in plants

Question 1

Why do plants require water?

Answer 1

• structure (turgid cells)
• transport medium
• chemical reactions

Question 2

When is osmosis used in plants?

Answer 2

Used to uptake water

Question 3

When is active transport used in plants?

Answer 3

When mineral ions are absorbed at the root hairs

Question 4

What is glucose made for?

Answer 4

energy - growth + repair

Question 5

What type of sugar is sucrose and what is it made from?

Answer 5

Disaccharide, made of glucose and fructose

Question 6

Name of plants’ networks of tubes

Answer 6

Vascular bundles

Question 7

Where is water absorbed?

Answer 7

At root hair cells

Question 8

Is the xylem a one-way or two-way journey for water?

Answer 8

One-way

Question 9

What is transported in the xylem?

Answer 9

Mineral ions and water ONLY

Question 10

Where is sugar made?

Answer 10

In the leaf

Question 11

Where is sugar stored?

Answer 11

In the roots (as starch) or the leaf

Question 12

Where is water requires?

Answer 12

Leaf, palisade cells (for photosynthesis)

Question 13

Xylem = water or sugar?

Answer 13

Water

Question 14

Phloem = water or sugar?

Answer 14

Sugar

Question 15

What is transported in the phloem?

Answer 15

Amino acids and sucrose ONLY

Question 16

Where will the sugar solution be in the plant?

Answer 16

All over the plant

Question 17

Is the phloem a one-way or two-way system?

Answer 17

Two-way

Question 18

Why does the xylem have no cytoplasm or organelles and how does this help?

Answer 18

Because the cells are dead - no obstruction to flow of water

Question 19

From where is the movement in the xylem?

Answer 19

From roots to shoot

Question 20

How does the xylem form?

Answer 20

• end walls removed

- cells join to form long tubes

Question 21

What are the walls of the xylem thickened with and why?

Answer 21

Lignin - waterproof + strong, stops cells collapsing inwards and gives stem support

Question 22

What is special about the end of the cell in the phloem?

Answer 22

Acts like a sieve - allows contents to pass through cells

Question 23

Does the phloem have a cytoplasm?

Answer 23

Yes - thin layer (cell needs to be kept alive to help transport)

Question 24

Which vessel has companion cells: xylem or phloem?

Answer 24

Phloem

Question 25

What do companion cells not transport?

Answer 25

Sugars

Question 26

What do companion cells do?

Answer 26

Help with the life processes of the phloem

Question 27

Where is the xylem located in the leaf and why?

Answer 27

near the surface - delivers water for photosynthesis

Question 28

Where is the xylem located in the stem and why?

Answer 28

Towards the middle - helps provide support

Question 29

Where is the xylem located in the root and why?

Answer 29

Close to the edge for quick transport

Question 30

Where is the phloem located in the root and why?

Answer 30

Close to edge to allow for sugar storage as starch

Question 31

What are nitrate ions needed for?

Answer 31

needed to make amino acids and proteins

Question 32

What are magnesium ions needed for?

Answer 32

Needed to make chlorophyll

Question 33

What is the benefit of having no end walls in the xylem?

Answer 33

Forms a continuos transport system

Question 34

What are the cell walls in the phloem made from?

Answer 34

Cellulose

Question 35

From where are substances transported in the phloem and where to?

Answer 35

From leaves to growing points/storage areas

Question 36

How do root hairs reach the soil water?

Answer 36

Long thin outer projection penetrates between soil particles

Question 37

Is the water absorbed pure?

Answer 37

No - has some solutes in it

Question 38

What is the concentration of the solutes in the water compared the concentration of the root hair cells' solutes?

Answer 38

Water solutes' concentration is much lower

Question 39

Why does water enter the cell by osmosis?

Answer 39

Soil water has a higher concentration of water molecules

Question 40

What is the effect of osmosis?

Answer 40

- dilutes contents of the cell | - increases concentration of water molecules

Question 41

Where does the water move to from the root hair cells?

Answer 41

Into the cortex of the root

Question 42

Explain the concentration gradient that the water travels along

Answer 42

- travels down water concentration gradient | - from an area of more water molecules to an area of fewer water molecules

Question 43

Does the water concentration gradient stay the same and why/

Answer 43

- gradient is maintained | - water is continually being taken up by xylem in middle of the root

Question 44

What is the epidermis covered by and what is the effect of this?

Answer 44

Covered by waxy cuticle so is impermeable to water

Question 45

What is transpiration?

Answer 45

The evaporation of water from the surface of a plant.

Question 46

What does most water pass out of the stomata as?

Answer 46

Water vapour

Question 47

What happens after water leaves the mesophyll cells?

Answer 47

Evaporates into air spaces between the spongy mesophyll

Question 48

Where does the water vapour go and by what process?

Answer 48

Diffuses out through the stomatal pores

Question 49

What is the result of the lack of water at the mesophyll cells?

Answer 49

Cells have lower concentration of water molecules

Question 50

What is the result of a lower concentration of water molecules?

Answer 50

Draws water by osmosis from mesophyll cells

Question 51

What supplies the leaf mesophyll tissues with water?

Answer 51

Xylem vessels

Question 52

What does transpiration cause?

Answer 52

Causes water to be pulled up the xylem in the stem + roots in continuos flow (transpiration stream)

Question 53

What is cohesion?

Answer 53

Ability of water to attach to other water molecules

Question 54

What is adhesion?

Answer 54

Ability of water to stick to other tissues

Question 55

What are the functions of the transpiration stream?

Answer 55

- carry mineral ions for synthesis of amino acids and chlorophyll - keep turgor pressure high in leaves - evaporation cools the leaves - allows O2 and CO2 to diffuse freely

Question 56

How does temperature affect the rate of transpiration?

Answer 56

- hot - energy of particles = high | - hot - rate of transpiration = fast

Question 57

How does humidity affect the rate of transpiration?

Answer 57

- humid - rate of transpiration = slow | - humid - concentration gradient = low

Question 58

How does wind speed affect the rate of transpiration?

Answer 58

- still air - transpiration slows down | - moving air - transpiration speeds up, concentration gradient high

Question 59

What is the concentration of transpiration in general?

Answer 59

High to low

Question 60

How do leaves make carbohydrates?

Answer 60

By photosynthesis

Question 61

What do leaves use carbohydrates for?

Answer 61

To make amino acids, proteins and oils

Question 62

What is the transport in the phloem called?

Answer 62

Translocation

Question 63

Why is translocation an active process?

Answer 63

Energy is needed to make sap move through phloem tubes

Question 64

What is phototropism?

Answer 64

Plant growth movement with light as the stimulus

Question 65

What is geotropism?

Answer 65

Growth of parts of a plant in response to gravity

Question 66

What are tropisms?

Answer 66

Plant growth movements and how they respond to certain stimuli