Flashcards in 3.3 Xylem, Phloem & transport Deck (42):
what does xylem transport?
water and minerals
which way does xylem transport water and minerals?
roots to leaves
is xylem made of dead or alive tissue?
what are dead xylem vessels impregnated with?
lignin for support
xylem vessels also have pits what does this do?
let water flow from one xylem to another in case of collapsing
what does phloem transport?
in what direction can the phloem transport sugars?
roots to leaves
leaves to roots
what does phloem consist of?
companion cells and sieve tube elements
is phloem lignified?
no it is a long hollow structure
what are sieve tube elements?
cells of the phloem allowing nutrients to flow through the plants in a watery stream
how are sieve tube elements arranged in the phloem?
end to end
what are companion cells?
cells of the phloem aiding the movement of nutrients
what process do plants need to move water for?
the sugars produced in photosynthesis are needed for what and where?
respiration throughout the plant
when transporting water and minerals what do the roots hairs give the root?
large surface area for water uptake
once in the root water travels from the cortex to where?
vascular tissues in the stele
what does the cortex consist of?
undifferentiated parenchyma cells
in the xylem water moves through pits to what cells?
elongated tracheid cells
how do xylem vessels join to form continuous vessels?
end to end
what do sclerenchyma fibres in the xylem provide?
in the leaf vascular bundles are surrounded by what sort of tissue?
what does mesophyll tissue contain?
air spaces into which water evaporates
water vapour leaves the plant via the what?
how do stomata control water loss?
opening and closing
give an example of the main sugar transported in the phloem?
what are tubers?
enlarged roots which store sugars by converting them to starch
give an example of a tuber:
a tuber grows as a plant is doing what?
when does a tuber break down and why?
to provide sucrose when it is needed for growth
phloem consists of sieve tubes supported by what type of cell?
sieve tubes lack organelles to allow what to move easily?
how do fruits store sugars?
by converting them to starch
fruits don't provide energy for the plant, so what do they provide energy for?
the daughter plant
fruits also attract animals that do what?
distribute their seeds
what type of molecule is lignin, where is it found and what does it do?
carbohydrate found in xylem, providing support
what does thick walled xylem parenchyma (tissue) do and contain?
contain tannin deposits
(xylem) what is tannin, what does it do?
bitter tasting chemical protecting plant tissues from attack by herbivores
(xylem) what can lignin form?
what do spirals of lignin in the lumen of the xylem help do?
reinforce the xylem vessels so they don't collapse under transpiration pull
which vessels are the main transporting components of phloem?
sieve tube elements
(phloem) areas between sieve tube elements become perforated to form what?