Plants were grown in a green house under 14 cycles of 12 hours light (day) and 12 hours dark (night). At the end of the 14^th cycle, plants were divided into 4 groups that were exposed to one of four experimental light conditions.

The following table shows the rate of photosynthesis under each of the experimental light conditions.

Plant Group	Treatment	Photosynthesis Rate %
1	Dark (no light)	0
2	Green light	14
3	Full spectrum, dim light	47
4	Full spectrum, bright light	100

1. Which of the variables in this experiment is the dependent/measured variable?
   1. Wavelength of light
   2. Light intensity
   3. Photosynthesis rate
   4. Number of days
    
2. The four groups of plants are kept under the experimental conditions indefinitely. Which group of plants will die first because of the light conditions?
   1. Group 1
   2. Group 2
   3. Group 3
   4. Group 4
    
3. The immediate cause of death in the previous question is lack of
   1. CO₂
   2. O₂
   3. glucose
   4. amino acids
    
4. Which group produces the most oxygen?
   1. Group 1
   2. Group 2
   3. Group 3
   4. Group 4