Transport in plants and structure of vessels

Question 1

what is a phloem

Answer 1

a tissue used to transport assimilates

Question 2

What is a xylem

Answer 2

a tissue used to transport water and minerals

Question 3

Why do plants need a transport system

Answer 3

to meet their high metabolic demand for o2, water, minerals etc..

to compensate for their small sa: vol ratio (large plants)

plants cant rely on diffusion alone.

Question 4

What direction does water and minerals travel in the xylem

Answer 4

Upwards

Question 5

What direction do assimilates travel in the Phloem

Answer 5

Up and Downwards

Question 6

What is a dicotyledonous plant

Answer 6

plants with two seed leaves and branching veins in leaf

Question 7

what two types of tissue also give strength to the vascular bundle

Answer 7

Collenchyma
Sclerenchyma

Question 8

what is a tap root

Answer 8

the thick main root of a plant

Question 9

what is the pericycle and what is it made of

Answer 9

The pericycle is a thin layer of plant tissue between the endodermis and phloem.
Made of meristem tissue

Question 10

What is the function of the vascular cambium

Answer 10

Vascular cambium- pushes the xylem and phloem apart.

Question 11

Name a b c and d

Answer 11

A- Collenchyma
B- Parenchyma
C- Vascular cambium
D-pith

Question 12

What is the function of lignin in xylem

Answer 12

Impregnates the walls of the xylem, killing cells and making them waterproof

Question 13

How does lignin cause long collums of xylem

Answer 13

Lignin kills the cells in the wall. The end walls and contents of cell begin to decay.
Causing a long column with dead cells and no contents.

Question 14

How does lignin help the xylem to stay open

Answer 14

The lignin prevents xylem collapsing and keeps it open. Also provides flexibility to the stem/branch

Question 15

What shape is lignin in the xylem

Answer 15

Spiral rings

or could be broken rings

Question 16

How are bordered pits in the xylem formed

Answer 16

Lignification is incomplete. Leaving gaps in the cell wall making bordered pits.

Question 17

What do bordered pits do (xylem)

Answer 17

Allow water to leave 1 vessel and pass into the next vessel

Question 18

A xylem vessel can sometimes be paired with a “xylem parenchyma”, what are the two functions of this

Answer 18

• contain food stores to enable xylem to repair if necessary or grow

-contain tanin which is bitter, herbivores taste tanin and prevent herbivores eating plant

Question 19

what direction does phloem move

Answer 19

source to the sink

Question 20

what direction does water in xylem flow

Answer 20

upwards

Question 21

why does the phloem transport sucrose rather than glucose

Answer 21

more stable form of sugar, not as easily used up

Question 22

which vessel is alive? xylem or phloem

Answer 22

Phloem, to perform active transport in translocation.

Question 23

what are the name of the individual segments of the phloem vessel

Answer 23

Sieve tube elements

Question 24

what structure is interlinked to the side of a xylem

Answer 24

Companion cell

Question 25

Between the Companion cell and phloem, there is plasmodesmata, what does the plasmodesmata allow to happen.

Answer 25

Allows substances to flow through the two cells

Question 26

describe the organelles in the sieve tube elements

Answer 26

very little cytoplasm, no nucleus to leave space for mass flow of sap

Question 27

what is an advantage to the xylem vessel being narrow

Answer 27

it prevents the water column breaking

Question 28

why is it beneficial for there to be cohesion and tension in the xylem to pull the water upwards

Answer 28

because the water can be pulled upwards to replace the water lost by transpiration