Transport in Plants

Question 1

dicotyledonous plants

Answer 1

plants with 2 seed leaves and a branching pattern of veins in the leaf

Question 2

meristem

Answer 2

a layer of dividing cells (the pericyle)

Question 3

phloem

Answer 3

transports dissolved assimilates

Question 4

vascular tissue

Answer 4

consists of cells specialised for transporting fluids by mass flow

Question 5

xylem

Answer 5

transports water and minerals

Question 6

companion cells

Answer 6

cells that help to load sucrose into the sieve tubes

Question 7

sieve tube elements

Answer 7

make up tubes in phloem that carry sap up and down the plant (separated by sieve plates)

Question 8

plasmodesmata

Answer 8

gaps in the cell wall containing cytoplasm that connects 2 cells

Question 9

potometer

Answer 9

device that can measure rate of water uptake as a leafy stem transpires

Question 10

transpiration

Answer 10

the loss of water vapour from the aerial parts of a plant, mostly through stomata in the leaves

Question 11

adhesion

Answer 11

the attraction between water molecules and walls of the xylem vessel

Question 12

cohesion

Answer 12

attraction between water molecules cause by hydrogen bonds

Question 13

hydrophyte

Answer 13

a plant adapted to living in water or where the ground is very wet

Question 14

xerophyte

Answer 14

a plant adapted to living in dry conditions

Question 15

assimilates

Answer 15

substances that have become part of the plant

Question 16

sink

Answer 16

a part of the plant where those materials are removed from the transport system

Question 17

source

Answer 17

a part of the plant that loads material into the transport system

Question 18

translocation

Answer 18

the transport of assimilates throughout a plant

Question 19

xylem tissue consists of

Answer 19

vessels to carry water and dissolved mineral ions, fibres to help support plant, living parenchyma cells as packing tissue to separate and support the vessels

Question 20

function of phloem tissue

Answer 20

transport assimilates (mainly sucrose and amino acids) around the plant

Question 21

cambium

Answer 21

layer between xylem and phloem, has meristem cells that divide to form new xylem and phloem

Question 22

pericycle

Answer 22

parenchyma cells which remain meristematic and divide to form lateral roots

Question 23

cortex

Answer 23

large space surrounding vascular bundle composed of parenchyma

Question 24

3 pathways in root hair cells taken by water

Answer 24

symplast, vascular, apoplast

Question 25

where does water evaporated from in plants

Answer 25

via stomata of leaves, cuticle of leaves, stems (via lenticles on woody stems and somata on herbaceous stems) and flowers

Question 26

transpiration

Answer 26

driving force behind the uptake of water from the soil and its delivery to the leaves due to transpiration stream

Question 27

stomata

Answer 27

a pore essential for exchanging gases for photosynthesis/respiration but allow water loss

Question 28

guard cells

Answer 28

2 kidney shaped cells which open and close the stomata via change in their turgidity (cellulose walls are thickened –> less flexible)

Question 29

when stomata are closed…

Answer 29

guard cells less turgid, less curved, water being lost

Question 30

when stomata are open…

Answer 30

guard cells more turgid, more curved, water being gained

Question 31

hydathodes

Answer 31

specialised structures at tips/margins of hydrophyte leaves, they can release water droplets which may evaporate from the leaf surface

Question 32

what happens if phloem vessel if cut

Answer 32

pores in the sieve plates become blocked very quickly by proteins than callose which stops the sap from flowing

Question 33

2 types of terrestrial plants

Answer 33

xerophytes and hydrophytes