CBSE Class 10 Answered

Plants utilize carbon dioxide and release oxygen during photosynthesis. When plants do not carry out photosynthesis, e.g., at night, they use cellular respiration for energy, releasing some carbon dioxide in the air. During day time, there is light coming from the sun. Plants need light to photosynthesize. At night there is no light, so plants cannot photosynthesize. Instead, they respire. Also, after death, decomposition of plants releases carbon compounds such as carbon dioxide and methane.