3.3.1 transport in plants

Question 1

dicotyledonous plants

Answer 1

plants with 2 seed leaves & branching pattern of veins from leaf

Question 2

meristem

Answer 2

layer of dividing cells (pericycle)

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 & minerals

Question 6

why do multicellular plants need a transport system?

Answer 6

1. smaller SA:Vol
2. deliver nutrients & remove waste products
   - water/minerals root to leaves
   - sugars from leaves to rest of plant
3. different nutrient requirements
   eg. autotrophic
4. metabolism in plants is generally slower (than animals)
   - nutrients supplied at lower rate
   - transport system doesn’t need to be as effective
   - no need for pump
   - some nutrients supplied by diffusion eg. photosynthetic gases

Question 7

what does the transport system in plants consist of

Answer 7

specialised vascular tissue

Question 8

name the 2 specialised vascular tissue & what they transport

Answer 8

1. xylem tissue = water & soluble mineral ions travel upwards
2. phloem tissue = assimilates (eg. sugars) travel up OR down

Question 9

describe the distribution of vascular tissue in dicotyledonous plants

Answer 9

• distributed throughout the plant
• xylem & phloem found together in vascular bundles
• bundles may also contain other tissues (eg. collenchyma, sclerenchyma) which give bundle more strength/support plant

Question 10

where is the vascular bundle found

Answer 10

centre of young root

Question 11

describe the structure of the vascular bundle in the root

Answer 11

• central core of xylem (often in X shape)
• phloem found between arms of X-shaped xylem tissue
  –> provides strength to withstand pulling forces to which roots are exposed

Question 12

what components are also present around the vascular bundle in the root

Answer 12

• around bundle, there’s a special sheath of cells called endodermis
• inside endodermis = layer of meristem cells called pericycle

Question 13

in a plan diagram of a root, where is the medulla located

Answer 13

between central vascular bundle & endodermis

Question 14

endodermis key role

Answer 14

getting water into xylem vessels

Question 15

draw & label plan diagram of a root

Answer 15

pg. 208 of textbook & in class booklet

Question 16

where are the vascular bundles found within the stem

Answer 16

found near outer edge

Question 17

what are the vascular bundles like in non-woody plants

Answer 17

separate & discrete

Question 18

what are the vascular bundles like in woody plants & what does this provide the plant with

Answer 18

bundles are separate in young stems, but become continuous ring in older stems
–> provides strength & flexibility to withstand bending forces to which stems/branches are exposed

Question 19

describe stem plan diagram

Answer 19

• xylem found towards inside of vascular bundle
• phloem on outside of vascular bundle
• in between phloem/xylem = cambium
• medulla/pith = main area surrounding vascular bundles (inside)
• epidermis = outer layer
• collenchyma = layer inside epidermis
• cortex = outside of vascular bundles (borders collenchyma)
• sclerenchyma = outer/third layer of vascular bundle & contains lots of lignin

Question 20

what’s the cambium

Answer 20

layer of meristem cells that divide to produce new xylem/phloem

Question 21

phloem consists of

Answer 21

sieve tube element & companion cell

Question 22

draw a plan diagram of a stem

Answer 22

pg 209 in textbook & in class booklet

Question 23

describe leaf plan diagram/structure

Answer 23

• vascular bundles form midrib & veins of leaf
• dicotyledonous leaf has branching network of veins that get smaller as they spread away from the midrib
• each vein = xylem located on top of phloem

Question 24

name components of leaf plan

Answer 24

• xylem & phloem (midrib)
• upper epidermis
• palisade mesophyll
• vein
• spongy mesophyll
• lower epidermis

Question 25

draw leaf plan diagram

Answer 25

pg 209 in textbook & in class booklet