Factors of Photosynthesis Flashcards
(15 cards)
Why is a plant destarched before photosynthesis experiments?
To remove stored starch so results reflect only the current experiment.
How is a plant destarched?
By keeping it in darkness for 48 hours.
What shows chlorophyll is necessary for photosynthesis?
Only green parts of a variegated leaf turn blue-black with iodine.
Why is the leaf boiled in water before the starch test?
To break down cell walls and denature enzymes.
Why is the leaf warmed in ethanol?
To remove chlorophyll which can mask colour change.
What result shows starch is present after iodine is added?
Blue-black colour.
What result shows starch is absent after iodine is added?
Orange/brown colour remains.
What proves light is necessary for photosynthesis?
Only parts of the leaf exposed to light turn blue-black with iodine.
What is the setup to test if light is necessary?
A leaf with a light-blocking stencil is exposed to sunlight for 4–6 hours.
What proves carbon dioxide is necessary for photosynthesis?
Plant A with CO₂ turns blue-black; Plant B without CO₂ does not.
What chemical provides CO₂ in photosynthesis experiments?
Sodium bicarbonate (NaHCO₃).
What chemical removes CO₂ in photosynthesis experiments?
Sodium hydroxide (NaOH).
How is light intensity investigated in photosynthesis?
By changing the distance of a lamp from the plant and using a glass sheet to block heat.
How is CO₂ concentration changed in a photosynthesis experiment?
By varying the amount of hydrogen carbonate in the solution.
How is temperature investigated in photosynthesis experiments?
By placing setups in environments with different temperatures.
