All three processes (decomposition, photosynthesis andrespiration) can occur in the Light Bottles. Oxygen is producedduring photosynthesis and consumed by respiration and decompositionin the bottle.

In a healthy lake, ample photosynthesis occurs. In this case,which dissolved oxygen test bottle should have the highest levelsof oxygen?

    a. Time 0 orinitial bottle filled with lake water but not incubated inlake    
    b. Light bottlewith lake water incubated for 24 hours    
    c. Dark bottlewith lake water incubated for 24 hours