Biology Homework [Plant Leaves and Photosynthesis Required Practical] Flashcards
28/05/25 (20 cards)
What’s the relationship between light intensity and distance? HT ONLY
As distance increases the light intensity decreases. They are inversely proportional.
State the inverse square law HT ONLY.
1/d^2
Why is a thin leaf an adaptation for photosynthesis?
Short diffusion distances for gases to move in and out.
In the photosynthesis RP, state the apparatus used.
LED lamp, ruler, pondweed, beaker of water, sodium hydrogen carbonate solution, stopwatch.
What is the function of veins in the leaves?
Veins are the xylem and phloem vessels.
In the photosynthesis RP, state the dependent variable.
Volume of oxygen produced.
In the photosynthesis RP, state the independent variable.
Light intensity.
Which layer of the leaf contains the most chloroplasts?
Palisade mesophyll layer.
In the photosynthesis RP, what apparatus was used to measure volume of oxygen?
Gas syringe.
In the photosynthesis RP, why is it important to control other factors e.g temperature and carbon dioxide concentration.
They affect the rate of photosynthesis; we’re only investigating the effect of light on the rate of photosynthesis.
How are xylem vessels involved in photosynthesis?
Xylem transport water from the roots to the leaves for photosynthesis.
In the photosynthesis RP, how was reliability ensured?
By repeating at each distance.
In the photosynthesis RP, how is light intensity changed?
By using a ruler to change difference.
In the photosynthesis RP, why is it important for everyone to use the same size pondweed.
Size of pondweed will affect the amount of chlorophyll present which can affect the rate of photosynthesis.
How are phloem vessels involved in photosynthesis?
Phloem vessels carry glucose made in the leaf to where it’s needed in the rest of the plant.
In the photosynthesis RP, name the source of carbon dioxide.
Sodium hydrogen carbonate solution.
How are guard cells and stomata involved in photosynthesis?
Guard cells open and close the stomata to allow carbon dioxide in and oxygen out.
Why is a wide leaf an adaptation for photosynthesis?
Large surface area to absorb maximum sunlight.
In the photosynthesis RP, state the control variables.
Temperature, concentration of carbon dioxide, type of plant, size of pondweed, volume of water.
After changing the distance why is it important to wait 1 minute before taking measurements?
Allow time to acclimatise.
