7.1 Structure of transport tissues

Question 1

Plants need transport systems to meet their ___ ___
eg: ___

Answer 1

metabolic demands
eg: glucose, hormones, mineral ions

Question 2

Plants consist many layers of cells so cannot rely on ___ for this would be ___

Answer 2

diffusion , slow

Question 3

Plants have a ___ ___ which involves a network of vessels running through ___, ___, and ___.

Answer 3

vascular system, leaves, stem, roots

Question 4

Vascular system (2) How are they arranged?

Answer 4

Xylem , Phloem
are arranged together in vascular bundles

Question 5

Leaf structure (8)

Answer 5

Vascular bundles, upper epidermis, palisade mesophyll , lower epidermis , phloem , xylem , spongy mesophyll

Question 6

Stem Structure (7)

Answer 6

Vascular bundle, epidermis, cortex, phloem, xylem, cambium, pith

Question 7

Root Structure (6)

Answer 7

epidermis, phloem, xylem, cortex, endodermis

Question 8

Xylem and Phloem locations in the leaf

Answer 8

Xylem: upper
Phloem: lower

Question 9

Xylem and Phloem location in the stem

Answer 9

Xylem: inner
Phloem: outer

Question 10

Xylem and Phloem location in the root

Answer 10

Xylem: cross
Phloem: the rest

Question 11

Xylem function (3)

Answer 11

1. vascular tissue that carries dissolved minerals and water up the plant
2. Structural support
3. Food storage

Question 12

Location of the vascular bundle and why? –Xylem roots (3)

Answer 12

center core, helps the roots withstand the pulling strains as the plant transports water upwards and grows

Question 12

Location of the vascular bundle and why? –Xylem stem (3)

Answer 12

vascular bundle are located outside, the xylem tissue is found on the inside – closest to the center of the stem to help support the plant

Question 13

Location of the vascular bundle? –Xylem leaf (3)

Answer 13

Form the midrib and veins – spread from the center of the leaf, Xylem is found on the upper side (closest to the upper epidermis)

Question 14

Function of the phloem (2)

Answer 14

1. Transport organic compounds
   eg: sucrose
   from the source to the sink –> these can occur up and down

Question 15

Phloem structure

Answer 15

Complex tissue – bulk made up of sieve tube elements (main conducting cells) – companion cells

Question 16

Location of the vascular bundle? –Phloem roots (2)

Answer 16

center core, on the edges of the center core

Question 17

Location of the vascular bundle ? – Phloem stems (2)

Answer 17

Located outside and phloem is found on the outside

Question 18

Location of the vascular bundle? – Phloem leaves (3)

Answer 18

form the midrib and veins – spread from the center phloem tissue found on the lower side of the bundles

Question 19

Function of Lignified cell walls (xylem)

Answer 19

adds strength to withstand hydrostatic pressure so vessels do not collapse

Question 20

No end plates function (xylem)

Answer 20

allows the mass flow of water and dissolved solutes as cohesive and adhesive forces are not delayed

Question 21

Cohesive(xylem)

Answer 21

between water molecules

Question 22

adhesive(xylem)

Answer 22

between water molecules and xylem wall

Question 23

No protoplasm – cells are dead when mature function (xylem)

Answer 23

does not delay the mass flow of water and dissolved solutes

Question 24

Pits in walls (in non-lignified section) function (xylem)

Answer 24

lateral movement of water allows for continuous flow in case of air bubbles forming in the vessel

Question 25

The small diameter of vessels function (xylem)

Answer 25

helps prevent the water column from breaking

Question 26

Structure in xylem vessel (5)

Answer 26

1. Lignified cell walls
2. no end plates
3. no protoplasm (cells are dead when they mature)
4. pits in walls (in non-lignified sections)
5. Small diameter of vessels

Question 27

Phloem sieve tube elements structures (4)

Answer 27

1. sieve plates with sieve pores
2. cellulose cell wall
3. no nucleus, ribosomes, or vacuole
4. thin cytoplasm

Question 28

Phloem structure: sieve plates with sieve pores – function

Answer 28

allows for continuous movement of organic substances

Question 29

Phloem Structure: cellulose cell wall – function

Answer 29

strengthens the wall to withstand the hydrostatic pressures that move assimilates

Question 30

Phloem Structure: no nucleus, ribosomes or vacuole in mature cells – function

Answer 30

maximizes space for movement of assimilates

Question 31

Phloem structure: thin cytoplasm – function

Answer 31

reduces friction to facilitate movement of assimilates

Question 32

Companion cells Phloem companion cell structure (4)

Answer 32

1. nucleus and other organelles present
2. transport proteins in plasma membranes
3. age numbers of mitochondria
4. plasmodesmata (channels in cell wall)

Question 33

Xylem and Phloem’s key differences:
1. Living cells
2. Substances transported
3. process of transportation
4. diction of flow
5. presence of end walls
6. cell wall material

Answer 33

1. X: no P: yes (companion cells)
2. X: water and mineral ions P: organic compounds / assimilates
3. X: transpiration P: Active translocation
4. X: One way / upwards (roots –> leaves) P: two ways — up or down
5. X: no P: yes (sieve plates)
6. X: Lignin and cellulose P: cellulose