AP Biology...quick question

<p>if you were testing the effect of varying amounts of light on dissolved oxygen in an alge-rich water culture and one recived 0% light(Dark) and the other recived 100% Light(initial), why does Initial-Dark= Respiration?</p>

<p>oh yea, the Initial used o2 in respiration and the o2 was given off in photosynthesis
the Dark used o2 in respiration and there was no photosynthesis</p>