Plant Nutrition I Flashcards
what is the equation for photosynthesis?
carbon dioxide + water –(light / cholorphyll)-> glucose + oxygen
6CO2 + 6H2O —> C6H12O6n+ 6O2
what is chlorophyll?
the chemical found inside chloroplasts which allows plants to absorb light
what are chloroplasts?
they contain chlorophyll
label this chloroplasts and chlorophyll diagram
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why are most plants green?
becasue most plants don’t absorb the colour green, they reflect it
during photosythesis … energy is absorbed by a pigment called … which can be found in the … of plant cells
this light energy is then used to convert … from the air to … from the soil into a simple sugar called …
as a by-product of photosnythesis … is made
during photosythesis **light **energy is absorbed by a pigment called chlorophyll which can be found in the chloroplasts of plant cells
this light energy is then used to convert **carbon dioxide **from the air to water from the soil into a simple sugar called glucose
as a by-product of photosnythesis oxygen is made
what is the test for glucose?
glucose made by plants is stored in plants in the form of starch which can be tested by iodine solution which turns from brown to blue/black
how do you test a leaf for starch?
- remove a leaf from a plant
- boil it in a test tube for 30 seconds
- boil it in ethanol to remove colour
- wash the now colourless leaf in cold water
- add iodine solution
how do demonstrate that carbon dioxide is needed for photosynthesis?
soda lime:
soda lime traps carbon dioxide by a chemical reaction and removes it from the air
leaves grown in the presence or absence of soda lime can then be tested for strach production using iodine
in the presence of carbon dioxide, leaves will turn blue/black when tested with iodine
lime water:
alternatively, the consumption of carbon dioxide can be tested using lime water
if photosynthesis has taken place, this will be less cloudy than when photosnythesis has not taken place
how do you demonstrate that light is needed for photosynthesis?
by covering a section of the leaf with paper, no light can get in
light needs to be absorbed by the chlorophll to convert carbon dioxide into glucose for photosynthesis
the section of the leaf covered will remain brown (iodine solution) because no starch is present because glucose has not been made
the non-covered part of the leaf will turn blue/black when tested with iodine solution
how do you demonstrate that chlorophyll is needed for photosynthesis?
test a green area of a leaf (with chlorophyll) with iodine solution and it will turn blue/black indicating that glucose has been made
test a white area of leaf (without chlorophyll) with iodine solution and it will remain brown (iodine colour) indicating that glucose has not been made
how do you demonstrate that oxygen is produced in photosynthesis?
an underwater plant that is good at photosnythesising is placed under water and a test tube on top
the gas formed will collect at thetop of of the test tube
once full, you an test for oxygen by placing a glowing splint in the test tube
if the splint relights oxygen is present
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what is the function of a leaf?
to absorb light and carry out photosynthesis (chlorophyll is needed)
to import raw materials for photosynthesis (CO2 and water)
to get rid of photosynthesis waste products (O2)
to export products from photosynthesis to parts of the plant that need them
label this leaf structure
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label this leaf cross section diagram
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what is the function of the waxy cuticle?
waterproof
reduces water loss
reduced infection by fungi
what is the function of the upper epidermis?
protection
no chloroplasts
absorbs harmful light but allows light for PS to pass through
what is the funtion of the palisade cells?
tightly packed, elongated
lots of chloropasts
high rate of photosynthesis
what is the function of the spongy cells?
loosely packed with air spaces between cells
some chloroplasts
some photosnythesis
what is the function of the air spaces?
between spngy cells
provides air channels through leaf allowing gas exchange
what is the function of the leaf vein: xylem?
rigid vessels with lignin
carry water and minerals from root to stem and leaves
what is the function of the leaf vein: phloem?
vessels of thin living cells
sieve tube cells that form tubes
carry dissolved sugars around the plant to points where suar is used or stored as starch
what is the function of the guard cells?
change shape depending on amount of water inside
control opening and closing of stomata
what is the function of the stomata?
space between guard cells
control the gas exchange and water loss from leaf
how have leaves adapted to absorb light and carry out photosynthesis?
(chlorophyll is needed)
lots of chloroplasts
chlorophyll in palaside cells on top can absorb a lot of sunlight
chloroplasts on all layers absorb all the sunlight that goes through
how doeswater enter the stomata?
by osmosis
when there is light and CO2, does the stomata open or close? how doe sit do this?
opens
guard cells are turgid (filled with water)
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when it is dark, there is a drought or it is cold, does the stomata open or close? why?
close
guard cells are flaccid (not filled with water)
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how do you carry out a stomata peel observation?
- apply nail vanish to bottom of leaf
- leave for a few minutes
- put cellotape over nail varnished area
- gently peel off cellotaoe
- stick cellotape on glass slide
. observe under microscope
what are the uses of glucose?
photosynthesis:
CO2+ H2O —> O2 + glucose
respiration:
glucose + O2 —> CO2 + H2O
energy release
sucrose:
nectar
transport of sugar in phloem
lipids:
in cell membrane
energy storage in seeds
starch:
carbohdydrates
energy storage
cellulose:
cell wall
DNA:
genetic material
amino acids
proteins
nucleotides
chlorophyll
what is the main point of respiration?
to provide energy
what is sucrose?
a disaccharide made of glucose and fructose
how is sucrose transported through the plant?
it dissolves in water and is transported through the phloem
where is sucrose transported to and for what purpose?
all parts of the plant that don’t photosynthesis
can be used for respiration, storage and synthesis of other substances
is the main element of nectar which is ussed to attract pollinating animals
what is starch?
glucose that is not needed for respiration
where is starch stored?
starch grains in cells of their stems or roots or special organs (tuber)
why do cells convert glucose into starch?
so it doesn’t alter the osmotic potential in cells
what are lipids needed for?
building up a cell membrane
why are lipids good for long-term energy storage in seeds?
they have a higher energy content than starch
what is cellulose?
a polymer made up of 1000s of glucose molecules
what is cellulose used for?
it forms microfibrils which are very strong and used for structural support in the plant cell wall
what are proteins made of?
amino acids
what are some proteins used for?
to form enzymes or structural components of the cell
where does nitorgen come from for building amino acids?
it is absorbed as nitrate from the soil by the roots of the plant
what are nucleotides made of?
glucose, nitrogen, phosphous
why is DNA important?
there is no life without DNA
DNA defines nearly all characteristics
what material is needed to synthesis chlorophyll?
magnesium
why is chlorophyll important?
allows plants to absorb light
chlorophyll and light are needed for photosynthesis
what is glucose’s use and elements?
substrate for respiration
C, H, O
what is sucrose’s use and elements?
main sugar carried in phloem
also in nectar
C, H, O
what is chlorophyll’s use and elements?
absorption of life in photosynthesis
C, H, O, Mg
what are lipid’s use and elements?
components of cell membranes
long term energy storage (seeds)
C, H, O
what is starch’s use and elements?
storgae of carbohydrates
C, H, O
what is cellulose’s use and elements?
component of cell walls
C, H, O
what are nuecleotide’s use and elements?
components of DNA
C, H, O, N, P
what are amino acid’s use and elements?
components of proteins
C, H, O, N
if plants recieve full nutirents what will their growth be like?
normal
what is nitrate used for in plants and what happens if a plant lack nitrate?
is needed for making amino acids (these contain elements H, C, O and N)
plants eed amino acids to make protein which is required for plant gworth
if a plant lack nitrate then growth is stunted and the plant might have yellow leaves
what is magnesium used for in plants and what happens if a plant lack magnesium?
is needed for making chlorophyll - this plays an important part in trapping the light energy during photosynthesis
the colour of this pigment is yellowif a plant lacks magnesium then it will have yellow leaves
how are soil minerals controlled and why are they controlled?
adding inorganic fertiliser or manure to soil
extra minearls increase growth rate
how is soil struture controlled and why is it controlled?
ploughing fields to break up compact soil
allows better uptake of minerals and water
how is soil pH controlled and why is it controlled?
adding lime to acidic soil
low pH can reduce uptake of minerals
how is water controlled and why is it controlled?
watering
required for photosyntheiss
how is carbon dioxide controlled and why is it controlled?
required for photosynthesis
greenhouse (e.g. burning fossil fuels)
required for photosynthesis
how is heat controlled and why is it controlled?
greenhuse (e.g. burning fossil fuels)
required for photosynthesis
how is carbon dioxide controlled and why is it controlled?
greenhouse (e.g. artificial lightning)
required for photosynthesis
what features are controled when improving crop yield?
soil minerals
soil mixture
soil pH
water
carbon dioxide
heat
light
what is tropism?
the growth response of a plant to a directional stimulus
stimulus = light
what is the name of response, repsonse of shoots and repsonse of roots?
name of response: phototropism
repsonse of shoots: grow towards the light source (positive phototropism)
repsonse of roots: mostly none or negative phototropism
stimulus: gravity
what is the name of response, repsonse of shoots and repsonse of roots?
name of response: geotropism
repsonse of shoots: grow away from direction of gravity (negative geotropism)
repsonse of roots: grow towards direction of gravity (positive geotropism)
stimulus: water
what is the name of response, repsonse of shoots and repsonse of roots?
name of response: hydroptropism
repsonse of shoots: none
repsonse of roots: some grow towards direction of water (positibe hydrotropism)
stimulus: touch of an object/support
what is the name of response, repsonse of shoots and repsonse of roots?
name of response: thigmotropism
repsonse of shoots: some grow towards and bend around support (positive thigmotropism)
repsonse of roots: grow away from object (Negative thigmotropism
what is an auxin?
a hormone (plant growth substance) that is responsible for tropism
prodcued in the tip of the shoot
auxin diffused from the … of the …
it is destroyed by …
accumulates on the … side
causes cell … which leads to … the shoot toward the light
auxin diffused from the tip of the shoot
it is destroyed by light
accumulates on the shady side
causes cell elongation which leads to bending the shoot toward the light
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