Plant nutrition and transport in plants Flashcards
Define photosynthesis
process which plants manufacture carbohydrates from raw materials using energy from light
Are plants autotrophs
yes
Define autotrophs
organisms that are able to make their own food
Purpose of chlorophyll (2)
transfers light energy into chemical energy in molecules
used for synthesis (production) of carbohydrates
Word equation of photosynthesis
carbon dioxide + water –> glucose + oxygen
Balanced chemical equation of photosynthesis
6CO2 + 6H2O –> C6H12O6 + 6O2
Name layers of the structure of a leaf in order (7)
waxy cuticle
upper epidermis
palisade mesophyll
Spongy mesophyll
Lower epidermis
Guard cells
waxy cuticle
Features of palisade mesophyll cells (4)
where most photosynthesis occurs
contains many chloroplasts
columnar shape allows many cells to be tightly packed to maximise absorption
found close to upper surface of leaf
Stomata and guard cells function (3)
play role in gas exchange
gases enter and exit through stomata
guard cells open or close in response to environment
Function of xylem
transports water and minerals from root to leaves
Function of phloem
transports sugars (sucrose) and amino acids from leaves to other parts of plant
By which process is glucose produced
photosynthesis
What is glucose used for (5)
energy
growth of shoots
growth of young leaves
growth of fruit
root growth
Purpose of sucrose (2)
converted from glucose
less reactive than glucose so not lost if transported
Where is sucrose transported
phloem
Purpose of starch
storage of glucose
Function of nitrate ions
synthesis (production) of amino acids
Function of magnesium ions
chlorophyll production
Deficiency of magnesium and nitrate ions (2)
stunted growth
yellow leaves
What chemical is used to test for starch
iodine
Experiment layout for testing starch availability in plants (7)
remove leaf from plant
place in beaker of boiling water for 30 seconds to break open cells
place in boiling tube of ethanol inside the beaker of boiling water - removes chlorophyll from leaves
remove leaf after 1 minute using forceps
rinse leaf with cold water
spread leaf on white tile and drip iodine on it
positive result is blue/black
Define variegated leaves
leaves which have green and white parts
Answering 7 mark experiment question (8)
independent variable
dependent variables
control variable (2)
safety precautions
how you will set up the experiment
how and how often you record data
how you will analyse results
what results show
Determinants for the rate of photosynthesis (3)
light intensity
CO2 amount
temperature
Define limiting factor
factor at lowest level which limits rate of reaction
Purpose of water in plants (2)
needed for photosynthesis
maintain turgor pressure and keep structure
How is water absorbed into roots (3)
osmosis
high concentration of minerals in root cells
water drawn into cells from high water potential (soil) to low water potential (cells)
Adaptation of root cells
root hair cells increase surface area for osmosis
Transport of water in plant (3)
once inside root cells water passes through xylem vessels up stem into leaves
if leaf photosynthesizing, water lost through open stomata
process called transpiration
Define transpiration (3)
loss of water from a plant by evaporation at surface of mesophyll cells
also diffuses out as water vapour through stomata
draws more water and minerals through xylem and up roots
Define transpiration stream
flow of water through plant taking water up roots
Pathway of water through roots, stem and leaf (4)
root hair cells
root cortex cells
xylem
mesophyll cells
Purpose of lignin in xylem vessels
supports structure
How does water move upwards in the xylem (7)
transpiration pull made by water potential gradient between roots and leaves
water evaporates at surface of mesophyll cells
water vapour diffuses through stomata
creates water potential gradient
causes lower water potential compared to higher water potential in roots
water absorbed by root hair cells
water moves up xylem as unbroken column of water molecules - held together by cohesion
4 main factors which affect rate of transpiration (4)
Light intensity
Temperature
wind speed
humidity
How does light intensity impact rate of transpiration (3)
greater light intensity –> more stomata open for photosynthesis
more stomata –> more transpiration
all stomata open –> further increase in light intensity won’t affect rate of transpiration
How does temperature affect rate of transpiration (2)
greater temperature –> faster the particles in the air move
faster particles –> more water particles evaporate from leaf –> increases transpiration
How does wind speed affect rate of transpiration (3)
increase in wind speed –> moves water particles surrounding leaf away
increases water potential gradient between inside and outside of leaf
increases rate of transpiration
How does humidity affect rate of transpiration (3)
more humid –> more water in air
reduces water potential gradient between inside and outside of leaf
transpiration slows down
Experiment for investigating rate of transpiration (4)
bubble potometer to estimate rate of transpiration
as transpiration occurs xylem sucks up more
water
bubble will move along capillary tube
measure distance moved by air bubble every minute to calculate rate of transpiration
Define translocation
movement of sugars (sucrose) and amino acids in phloem of plant
Define source
where sugar is produced or supplied to plant
Define sink
where substance is used or converted to another substance
What is the source and sink in summer (2)
leaves are source
roots are sink
What is the source and sink in winter (2)
roots are source
leaves are sink
Where is xylem and phloem in root cross-section (2)
xylem is large hollow X centre
phloem on outer
Where is xylem and phloem on stem cross-section (2)
xylem on inside
phloem on outside
Where is xylem and phloem on leaf cross-section (2)
xylem above
phloem underneath
When and Why is active transport used to take in ions (3)
active transport is movement of particles from area of low concentration to area of high concentration against concentration gradient using energy
mineral ions in higher contents in plant than soil
root hair cells use active transport to get nutrients
How does cohesion work in a plant (4)
water molecules are cohesive
tension created at top of xylem tube when water moves out of xylem cells
tension pulls water molecules up xylem into leaf
which pulls molecules out root cortical cells into root xylem tubes
State the type of cell through which water enters a plant
root hair cell
State the type of energy required for photosynthesis
light energy
Adaptation of xylem (4)
hollow - to reduce resistance/allow efficient
flow
large cross-sectional area/wide - to allow transport of large volume of water
lignin to provide support
waterproof to prevent water loss
Explain how mineral ions enter a plant (2)
enter into root hair cell by active transport
moves against concentration gradient using energy
Which chemical is a product of photosynthesis that moves out of a green leaf through its stomata?
oxygen
In a leaf, water moves from the surface of a mesophyll cell and then out of the leaf into the atmosphere
What is the correct order of the processes involved?
evaporation –> diffusion
The list shows features of a plant leaf:
1 air spaces between spongy mesophyll cells
2 chloroplasts in mesophyll cells
3 contains a natural insecticide
4 xylem vessels close to mesophyll cells
Which features are adaptations for photosynthesis?
1,2 and 4
