Students place three identical plants inside three identical, sealed clear containers.
Container 1 is placed in direct sunlight for 24 hours.
Container 2 is placed inside a dark room with no light for 24 hours.
Container 3 is placed in a dark room for 12 hours and is then moved into sunlight for 12 hours.
Students measure the concentration of carbon dioxide in the air inside the container over a period of 24
hours and graph their results.
Concentration of CO, (ppm)
Time (min)
Which colored line on the graph above represents container 2?
O.
Ob
O
The black line.
The red line.
The blue line.