A group of students designed a series of experiments to investigate factors affecting the rate of photosynthesis in plants - VCE - SSCE Biology - Question 5 - 2002 - Paper 1
Question 5
A group of students designed a series of experiments to investigate factors affecting the rate of photosynthesis in plants. The plants were enclosed in clear plastic... show full transcript
Worked Solution & Example Answer:A group of students designed a series of experiments to investigate factors affecting the rate of photosynthesis in plants - VCE - SSCE Biology - Question 5 - 2002 - Paper 1
Step 1
Write a balanced chemical equation for the process of photosynthesis.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The balanced chemical equation for photosynthesis is:
6CO2+6H2O+radiant energy→C6H12O6+6O2
This equation shows that carbon dioxide and water, in the presence of light energy, are converted into glucose and oxygen.
Step 2
By referring to your balanced equation, explain why the oxygen concentration in the air surrounding the plants can be used as a measure of the rate of photosynthesis.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Oxygen is a byproduct of the photosynthesis process, as indicated in the balanced equation. The more photosynthesis occurs, the greater the production of oxygen. Therefore, measuring the oxygen concentration can provide a direct indication of the rate at which photosynthesis is taking place.
Step 3
Explain why the oxygen concentration in the plants decreased during the first 10 minutes of the experiment.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
During the first 10 minutes, the plants were kept in the dark, which inhibited the process of photosynthesis. Consequently, oxygen was being utilized for respiration by the plants, leading to a decrease in the concentration of oxygen. Without light, there was no production of oxygen through photosynthesis to replenish what was being consumed.