6. Plant nutrition Flashcards
What are 5 different forms which carbohydrates made in photosynthesis are stored?
starch, cellulose, glucose, sucrose, nectar
What is the use of starch?
stores energy
What is the use of cellulose?
builds cell walls
What is the use of glucose?
for respiration (provides energy)
What is the use of sucrose?
to be transported in phloem vessels
What is the use of nectar?
it attracts insects for pollination
Why are nitrate ions important for plants?
produce amino acids
Why are magnesium ions important for plants?
make chlorophyll
What is the effect of concentration of Co2 on photosynthesis?
when level increases, so does rate of photosynthesis since co2 is necessary to carry out photosynthesis. however, there will reach a point in which it will make no difference anymore because there is a limited number of chloroplasts in the leaf. the chloroplasts become the limiting factor.
What is the effect of light on photosynthesis?
when level increases, so does rate of photosynthesis since light is necessary to carry out photosynthesis. however, there will reach a point in which it will make no difference anymore because there is a limited number of chloroplasts in the leaf. the chloroplasts become the limiting factor.
What is the effect of temperature on photosynthesis?
when level increases, so does rate of photosynthesis since molecules have more energy at higher temperatures. however, there will reach a point, after optimum temperature, in which enzymes will denature and not function anymore, reducing rate of photosynthesis.
Define ‘photosynthesis’.
process which plants use energy from light to synthesise carbohydrates from raw materials
State the word equation for photosynthesis.
carbon dioxide + water → glucose + oxygen
What other two things does photosynthesis need to occur?
light and chlorophyll
What is chlorophyll?
green pigment in chloroplasts
What is the role of chlorophyll in photosynthesis?
converts light energy into chemical energy, for the synthesis of carbohydrates to occur
State the balanced chemical equation of photosynthesis.
6CO2 + 6H2O → C6H12O6 + 6O2
What are two adaptations of leaves that help them in their functions?
large surface area
thin
Name two reasons why leaves are thin.
- CO2 from the air can quickly diffuse to cells which perform photosynthesis
- sunlight can penetrate more easily
Name a reason why leaves have large surface areas.
- large area exposed to sunlight/air (can absorb more easily)
How is the cuticle adapted for its function?
waxy layer
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How are the upper/lower epidermis adapted for their function (except for guard cells)?
very thin layer, no chloroplasts, allows light to penetrate
How is the palisade mesophyll layer adapted for its function?
- many chloroplasts
- chloroplasts at edge of the cell for a large vacuole allowing more light to enter
How is the xylem adapted for its function?
made of dead cells: tubes are hollow and waterproof, allowing water to pass
How is the phloem adapted for its function?
sieve tubes for the transportation of sucrose
companion cells so that energy for transport is provided
How is a guard cell adapted for its function?
gain and lose water, causing them to change shape and open and close the stoma
How is the spongy mesophyll adapted for its function?
air spaces between cells, making diffusion of gases throughout the leaf possible
What is the function of the cuticle?
prevents water loss by evaporation from leaf
What is the function of the chloroplast?
photosynthesis occurs here
What are the functions of the upper/lower epidermis?
protects inner cells
What is the function of the palisade mesophyll layer?
photosynthesis occurs here
What is the function of the xylem?
transports water + mineral ions from roots to leaves
What is the function of the phloem?
transports sucrose away from leaf
What is the function of the guard cell?
in pairs, to control the size of a stoma’s opening
What is the function of the stomata?
it controls the diffusion of gases in and out of the leaf
What is the function of the air spaces?
leave space for diffusion of gases throughout leaf
What is the function of the upper epidermis?
protects inner cells
