Final answer:
In beakers under light, leaves perform photosynthesis, increasing oxygen and decreasing carbon dioxide, while snails undergo respiration, decreasing oxygen and increasing carbon dioxide levels. In the dark, all beakers only show respiration. The presence of light determines if photosynthesis takes place alongside respiration.
Step-by-step explanation:
In the given experiment with beakers containing spinach leaves, snails, or both, the primary processes occurring can be determined by the presence of light and the organisms involved. Spinach leaves perform photosynthesis in the presence of light by converting carbon dioxide into oxygen, while snails carry out cellular respiration, consuming oxygen and releasing carbon dioxide. In the dark, photosynthesis does not occur, so only respiration will be the active process.
For the beakers under the light bulb:
- Beaker with only leaves: Increase in Oxygen Level, Decrease in Carbon Dioxide Level (Photosynthesis).
- Beaker with only snail: Decrease in Oxygen Level, Increase in Carbon Dioxide Level (Respiration).
- Beaker with leaves and snail: Both Photosynthesis & Cellular Respiration will occur; the oxygen and carbon dioxide levels may vary depending upon the balance of the two opposing processes.
For the beakers in the dark closet:
- Beaker with only leaves: Decrease in Oxygen Level, Increase in Carbon Dioxide Level (Respiration).
- Beaker with only snail: Decrease in Oxygen Level, Increase in Carbon Dioxide Level (Respiration).
- Beaker with leaves and snail: Decrease in Oxygen Level, Increase in Carbon Dioxide Level (Both are respiring, no photosynthesis in the dark).