DENDROLOGY

Detailed explanation-1: -In daylight, plants are both respiring and photosynthesising, so oxygen and carbon dioxide are diffusing in and out of the leaves. But overnight, without sunlight, photosynthesis stops and stomata close. With just respiration taking place, only oxygen diffuses into the leaves and only carbon dioxide diffuses out.

Detailed explanation-2: -Photosynthesis is the process by which plants use energy from the sun to make food. They use carbon dioxide from the air and water from the soil to make sugar and oxygen. Most plants release oxygen only during the day, when the sun can power photosynthesis.

Detailed explanation-3: -You are correct, plants do release carbon dioxide (CO2) at night, although they also release CO2 during the day. This is a part of the process of respiration!