Photosynthesis Flashcards
(13 cards)
What is the equation for photosynthesis?
carbon dioxide + water (+ sunlight) -> glucose + oxygen
Side Notes:
- the glucose is stored as starch
- glucose formula is C6H12O6
- chlorophyll absorbs sunlight
Which factors affect the rate of photosynthesis?
Temperature
Carbon dioxide concentration
Light intensity
What is the test for starch?
- Test the sample with iodine solution.
- If the sample turns blue-black, starch is present.
What is the xylem?
It transports water.
Transpiration occurs here.
One direction (from roots to shoots).
Dead with cell walls containing lignin (woody).
End cell walls broken down to form a continous tube/straw.
What is the phloem?
It transports dissolved sugars & amino acids.
Translocation occurs here.
From sources to sinks, in all directions.
Cells have holes in end wall (sieve plates).
Alive
Describe the adaptations of a leaf.
Large surface area - can absorb more light
Waxy cuticle - reduces water loss
Explain an experiment to find where chlorophyll is in a leaf.
- Put leaf in a beaker of boiling water over a bunsen burner.
- Then place the leaf in ethanol in boiling water.
- Then wash the leaf in cold water.
- Then put iodine solution on the leaf on a white tile. Areas that contained chlorophyll will turn blue-black.
Explain the experiment for stomatal density?
- Coat the leaf surface with nail varnish, and wait for it to dry.
- Then peel off the layer and put it under a microscope.
- Count the number of stomata you see.
How does hydrogen carbonate indicator change?
It is usually orange.
It changes to yellow when a large amount of CO2 is present.
It changes to purple when a low amount of CO2 is present.
What is transpiration?
The evaporation of water from leaves. The water evaporates from the stomata. This means water moves via osmosis up to fill the space the evaporated water left behind. Then water is drawn from the soil into the root hair cells.
Mineral ions are taken up by active transport.
What is the rate of transpiration increased by?
High light intensity
High temperature
Air movement (wind)
Low humidity
What is a potometer?
A potometer can be used to measure the rate of transpiration. It works by releasing a small air bubble in the leaf so as the leaf loses water, the air bubble moves. The distance moved is measured over a certain time period.
What are pyramids of biomass?
Pyramid of numbers - how many organisms there are
Each level on a pyramid of numbers is called a trophic level.
Pyramid of biomass - how much dry mass of each organism there is
