Plant transport

?
Why do plants need transport systems?
metabolic demands, size, surface area
1 of 29
What are dicots?
Plants that make seeds containing two cotyledons
2 of 29
What is the function of xylem?
to transport water and mineral ions; support
3 of 29
What are three tissues in xylem?
xylem vessels, xylem parenchyma, xylem fibres
4 of 29
What is the function of phloem?
to transport organic solutes around the plant
5 of 29
What are sieve plates?
perforated sections of cell walls to allow phloem contents to flow through
6 of 29
What are companion cells?
a 'life support' to the phloem; linked by plasmodesmata to sieve tube elements
7 of 29
What is water used for in plants?
turgor pressure, evaporation for cooling, transport of mineral ions, photosynthesis
8 of 29
How are root hair cells adapted?
miscroscopic size, large SA:V ratio, thin surface layer, concentration of solutes in cytoplasm maintains water potential
9 of 29
What is the symplast pathway?
water travels from cytoplasm to cytoplasm through plasmodesmata
10 of 29
What is the apoplast pathway?
water travels through cell walls and intercellular spaces until the casparian ***** where it's forced to move into the cytoplasm and join the symplast
11 of 29
What is the casparian *****?
a band of suberin that form a waterproof layer around endodermal cells
12 of 29
Why does water move into the xylem from the endodermal cells?
the endodermal cells have a low solute concentration; they actively move minerals into the xylem
13 of 29
What evidence is there that active transport plays a role in root pressure?
when mitochondria are affected, root pressure disappears; increased temperature increases rp; guttation
14 of 29
What is transpiration?
the loss of water vapour from the leaves and stems
15 of 29
Explain the transpiration stream.
water evaporates from the mesophyll cells; water moves in from adjacent cells down CG; continuues up to the xylem where water moves out of it; due to adhesion and cohesion water moves up the xylem
16 of 29
What evidence is there to support the cohesion-tension theory?
tree diameters change at different times of day, air is drawn in when a xylem vessel breaks, plants can't bring water up if the stem is broken anywhere
17 of 29
What factors affect transpiration?
light intensity, humidity, temperature, air movement, soil moisture
18 of 29
What is translocation?
plants transport organic compounds in the phloem from sources to sinks
19 of 29
What are assimilates?
products of photosynthesis
20 of 29
What are some examples of sources?
green leaves, storage organs, food stores
21 of 29
What are some sinks?
growing roots, meristems, parts that are laying food stores
22 of 29
Explain phloem loading.
sucrose is moved into companion cells, H+ are pumped out by active transport, H+ and sucrose are cotransported back, water moves in, turgor pressure builds, water and assimilates move into sieve elements
23 of 29
Explain phloem unloading.
sucrose diffuses from the phloem into cells, water moves into surrounding cells
24 of 29
What are xerophytes?
plants in dry habitats that have adaptations
25 of 29
What adaptations do xerophytes have?
thick waxy cuticle, sunken stomata, reduced stomata, reduced leaves, hairy leaves, curled leaves, leaf loss, root adaptations
26 of 29
What are hydrophytes?
plants that live in water
27 of 29
What adaptations do hydrophytes have?
thin waxy cuticle, stomata stay open for a long time, reduced structure, wide and flat leaves, small roots, air sacs, aerenchyma
28 of 29
What are aerenchyma?
specialised parenchyma in leaves, stems and roots; large air spaces
29 of 29

Other cards in this set

Card 2

Front

What are dicots?

Back

Plants that make seeds containing two cotyledons

Card 3

Front

What is the function of xylem?

Back

Preview of the front of card 3

Card 4

Front

What are three tissues in xylem?

Back

Preview of the front of card 4

Card 5

Front

What is the function of phloem?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Human, animal and plant physiology resources »