Question

why plants release more oxygen during day time???

Answer 1

Coz they are doing photosynthesis during day time. At night they cannot perform photosynthesis because of no sunlight.

Answer 2

Plants release more oxygen during the daytime because they are 'awake', or their petals are not closed. During the nighttime, the plants go in a rest. Most oxygen is create through photosynthesis, and there cannot be any of that without sunlight.