xylem + phloem

Question 1

why do plants need specialised transport systems

Answer 1

multicellular so small SA:V
relatively big with high metabolic rate

Question 2

what is the role of xylem tissue

Answer 2

transports water and mineral ions

Question 3

what is the role of phloem tissue

Answer 3

transports sugars

Question 4

what do xylem and phloem tissue make up

Answer 4

a vascular bundle

Question 5

describe the vascular bundle in the roots of plants

Answer 5

xylem is in the centre surrounded by the phloem for support

Question 6

describe the vascular bundle in the stems of plants

Answer 6

xylem and phloem are near the outside to provide a scaffolding

Question 7

describe the vascular bundle in the leaves of plants

Answer 7

xylem and phloem make up a network of veins arranged with xylem facing outwards

Question 8

what is the structure of a xylem vessel

Answer 8

long, tube like structures formed from vessel elements joined end to end

Question 9

how does water pass up the xylem uninterrupted

Answer 9

no end walls on cells allowing for an uninterrupted tube of water to flow, dead cells with no cytoplasm

Question 10

what are xylem walls thickened with

Answer 10

lignin

Question 11

what is lignin

Answer 11

helps to support xylem vessels and prevents them from collapsing

Question 12

how do water and ions move in and out of the xylem

Answer 12

via non lignified pits

Question 13

what does phloem tissue contain

Answer 13

phloem fibres, parenchyma, sieve tube elements and companion cells

Question 14

what are sieve tube elements

Answer 14

living cells that form the tube for transporting solutes from the plant

Question 15

what are sieve tubes

Answer 15

sieve tube elements joined end to end

Question 16

how do solutes pass through the phloem

Answer 16

sieves have end walls with gaps which allows solutes to pass through