Question

plants breath at night but it live without breathing in day how & why ?

Answer 1

During day time, plants are actively carrying out two processes, photosynthesis and respiration. Photosynthesis uses carbon dioxide while respiration uses oxygen. Since, the plants carry out both the processes, the net effect is release of oxygen by plant as it is produced in excess. At night, photosynthesis stops while respiration continues to occur. So, plants take up oxygen at night for respiration.