Plant stems

Question 1

parenchyma

Answer 1

relatively unspecialised plant cells that act as packing in stems and roots to give support

Question 2

collenchyma

Answer 2

plant cells with areas of cellulose thickening that give mechanical strength and support to the tissues

Question 3

sclerenchyma

Answer 3

plant cells that have very thick lignified cell walls and an empty lumen with no living contents

Question 4

sclereids

Answer 4

sclerenchyma cells that are completely impregnated with lignin

Question 5

xylem

Answer 5

the main tissue transporting water and minerals around a plant

Question 6

phloem

Answer 6

the main tissue transporting dissolved food around the plant

Question 7

vascular bundle

Answer 7

part of the transport system of a plant, with phloem on the outside and xylem on the inside-often with strengthening sclerenchyma

Question 8

cambium

Answer 8

the layer of unspecialised plant cells that divide to form both the xylem and phloem

Question 9

protoxylem

Answer 9

the first xylem the plant makes; it can stretch and grow because the walls are not fully lignified

Question 10

metaxylem

Answer 10

consists of mature xylem vessels made of lignified tissue

Question 11

transpiration stream

Answer 11

the movement of water up from the soil through the root hair cells, across the root to the xylem, then up the xylem, across the leaf until it is lost by evaporation from the leaf cells and diffuses out of the stomata down a concentration gradient

Question 12

translocation

Answer 12

the active movement of substances around a plant in the phloem

Question 13

sieve plates

Answer 13

the perforated walls between phloem cells that allow the phloem sap to flow

Question 14

companion cells

Answer 14

very active cells closely associated with the sieve tube elements that supply the phloem vessels with everything they need and actively load sucrose into the phloem