3.3 Transport in Plants

?
why do plants need a transport system
they need a transport system to move water and minerals from the roots up to leaves and to move sugars from the water leaves the rest of the plant
1 of 38
What is the function of vascular tissues and how are they adapted for their functions
they are the transport in the plant - water and soluble mineral ions travel upwards through the xylem tissue and assimilates such as sugars travel up or down phloem tissue
2 of 38
How are vascular tissues distributed in dicotyledenous plants
they are distributed throughout the plant. the xylem and phloem are found in bundles and this gives strength and support to the plant
3 of 38
how are the phloem and xylem arranged in a young root
the central core of the xylem is often an X shape and the phloem is found between it and provides strength to withstand the pulling forces that the roots are exposed to
4 of 38
How are the phloem and xylem arranged in the stem
the xylem is found towards the inside of the vascular bundle and the phloem is a layer of cabium provides strength and flexibility.
pg 209
5 of 38
How are the phloem and xylem arranged in a dicotyledonous leaf
has branching network of veins that get smaller as they spread away from the midrib, with each vein, the xylem is located on top of the phloem
6 of 38
How is a plant dissected
wear eye protection
cut a very thin section of plant stem, use one sided razor blade or scalpel
place section on slide
place a few drops of acidified phloroglucino over you section
cover with a cover slip and observe using a light microscope
7 of 38
What do xylem vessels mainly consist of
vessels to carry the water and dissolved mineral ions
fibres to help support the plant
living parenchyma cells which as as packing tissue to separate and support the vessels
8 of 38
what is the structure of xylem vessels
lignin impregnates the walls of the cells, making walls water proof - lignin strengthens the vessel walls and prevents the vessel from collapsing
lignin thickening forms patterns in the cell wall which prevents the vessel from being too rigid and allows
9 of 38
what is the function of xylem vessels
it is a tissue which is used to transport water and mineral ions from the root up to the leaves and other parts of the plant
10 of 38
how are xylem vessels adapted for their function
aligned dead cells forms continuous column, tubes are narrows which means capillary action is effective - water can move sideways and minerals can be transported
11 of 38
what is the function and structure of phloem
it is a tissue used to transport assimilates around the plant. it consists of sieve tubes - made up of sieve tube elements and companion cells
12 of 38
what are sieve tubes elements
lined up up end to end to form sieve tubes, they have no nucleus and very little cytoplasm to allow for mass flow of sap they also have preferated cross wall which allow movement of sap and have thin walls
13 of 38
what are companion cells
in between sieve tubes; large nucleus and dense cytoplasm, they have numerous mitochondria to produce ATP for active processes. they carry out metabolic processes to load assimilates
14 of 38
What are the three main pathways of water travelling through cells
the appoplast pathway (through the paces in the cell wall), symplast pathway(enter the cell cytoplasm through plasma membrane pass through plasmodesmata), and the vacuolar(passes through the vacuoles) pathway
15 of 38
what is water potential
the measure of the tendency of water molecules to move from one place to another
16 of 38
how is water taken into the cell
water enter the cell down the water potential gradient due to osmosis and becomes turgid if the water potential inside the cell is lower than outside
17 of 38
how is water lost from the cell
if the water potential inside the cell is high than the water potential outside the cell and the plasma membrane is pulled away from the cell and goes through plasmolysis and becomes flaccid
18 of 38
how is water moved between cells
when plant cell are touching each other and will move from the cell with the less negative water potential
19 of 38
what is transpiration
it is the the loss of water vapour from the upper parts of the plant especially in leaves some water may evaporate through upper leaf limited by waxy cuticle majority is lost in the day as this is when photosynthesis can occur
20 of 38
why is transpiration important
it is essential for the plant to survive as it:
transports useful mineral ions up the plant
maintains cell turgidity
supplies water for growth, cell elongation and photosynthesis
supplies water that, as it evaporates, can keep the plant cool on hot da
21 of 38
what factors affect diffusion
light intensity
temperature
relative humidity
air movement
water availability
22 of 38
how is water taken up from the root and how does it move across the root
root cell have extension increase SA, they absorb mineral ions and water from soil. water moves across root cortex down water-potential gradient to endomermis. water may also travel through the apoplast pathway as far as endodermis
23 of 38
what is the role of the endodermis
water is moved across the root by active process in endodermis.
the casparian ***** blocks the appoplast pathway which ensures water and dissolved mineral ions have to pass into the cell cytoplasm
plasma membrane contain transporter proteins actively pu
24 of 38
what factors affect the transpiration stream
root pressure, transpiration pull and capillary action
pg 217
25 of 38
how does water leave the leaf
most water leaves the leaf as vapour through the stomata and tiny amounts leave through the waxy cuticle. this lowers the water potential in theses cells, causing water to enter them by osmosis from neighbouring cells, and is also drawn form the xylem in
26 of 38
what are the adaptation of xerophytes of terrestrial plants
this waxy cuticle to reduce water loss
stomata is often found on the underside of the leaf reduces evaporation from the sun
most stomata closed at night
deciduous plants lose thier leaves in winter, when
27 of 38
what are some examples of xerophytes
terrestrial plants, marram grass, and cacti
28 of 38
what are the adaptations of hydrophytes
many large air spaces in the leaf, which keeps the leaves afloat so that they are in the air and can absorb light
the stomata are on the upper epidermis
the leaf the has many large air spaces - this helps buoyancy,about will also allow O2 to diffuse qui
29 of 38
what are some examples of hydrophytes
water lillies, sacred lotus, white water lily
30 of 38
how do hydrophytes transpire
many plants contain specialised structures at the tips of margins of their leaves called hydathodes. these release water droplets which may then evaporate from the leaf surface
31 of 38
what is translocation
the transport of assimilates throughout a plant
32 of 38
what occurs during translocation
pg 220
33 of 38
what happens during active loading
pg 220
34 of 38
what happens during the movement of sucrose
pg 221
35 of 38
what happens at the source
pg 221
36 of 38
what happens at the sink
pg 221
37 of 38
what happens along the phloem
pg 221
38 of 38

Other cards in this set

Card 2

Front

What is the function of vascular tissues and how are they adapted for their functions

Back

they are the transport in the plant - water and soluble mineral ions travel upwards through the xylem tissue and assimilates such as sugars travel up or down phloem tissue

Card 3

Front

How are vascular tissues distributed in dicotyledenous plants

Back

Preview of the front of card 3

Card 4

Front

how are the phloem and xylem arranged in a young root

Back

Preview of the front of card 4

Card 5

Front

How are the phloem and xylem arranged in the stem

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 behaviour resources »