Question

give reason in plants oxygen release is major exchange during day time

Answer 1

because they prepare their food in presence of sunlight (day) and release oxygen in the process of photosynthesis

Answer 2

Because in day time in presence of sunlight plants follow the process of photosynthesis in which plant take carbon dioxide and release oxygen but in night there's no sunlight so no photosynthesis that's why plants exchange oxygen in day time.