Required practical - Investigating photosynthesis (AQA GCSE Biology Combined Science): Flashcards
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Practise the cards
10 cards from this deck
What is measured to determine rate of photosynthesis?
What is measured to determine rate of photosynthesis?
Oxygen bubbles
Purpose of sodium hydrogen carbonate solution
Purpose of sodium hydrogen carbonate solution
Provides CO₂ for photosynthesis
Direction cut end of pondweed should point
Direction cut end of pondweed should point
Upward
Why use LED lamps in this practical?
Why use LED lamps in this practical?
To avoid heating up the water
Number of repeat measurements needed at each distance
Number of repeat measurements needed at each distance
3 times
Wait time after moving lamp before counting
Wait time after moving lamp before counting
5 minutes
Effect on bubbles as lamp moves further away
Effect on bubbles as lamp moves further away
Fewer oxygen bubbles produced
How to calculate mean bubble count
How to calculate mean bubble count
Add three runs and divide by 3
Initial lamp distance from boiling tube
Initial lamp distance from boiling tube
10 cm
Inverse square law: effect of doubling distance
Inverse square law: effect of doubling distance
Light intensity becomes four times weaker