Respiration is a vital process that occurs in all living cells, including plants. It is the process by which cells break down organic molecules to release energy in the form of ATP (adenosine triphosphate). Respiration in plants is similar to respiration in animals, but there are some differences.

- Respiration occurs in all living cells: Respiration is a fundamental process that occurs in all living cells, whether they are plant cells or animal cells. It is essential for the survival of the cell as it produces energy required for various cellular activities.

- Day and night respiration: Unlike animals, plants undergo respiration both during the day and night. During the day, plants undergo photosynthesis, a process in which they use sunlight, water, and carbon dioxide to produce glucose and oxygen. However, they also simultaneously undergo respiration to break down the glucose produced during photosynthesis to release energy. At night, when there is no sunlight available for photosynthesis, plants solely rely on respiration to produce energy.

- Formation of vitamins: Respiration in plants is not directly responsible for the formation of vitamins. Vitamins are organic compounds that are required in small amounts for the proper functioning of the body. While plants do produce some vitamins, their synthesis is not directly linked to respiration. Plants primarily synthesize vitamins through various metabolic pathways.

- Requirement of CO2: Respiration in plants often requires carbon dioxide (CO2). During respiration, plants utilize oxygen (O2) and glucose to produce carbon dioxide, water, and energy. The carbon dioxide produced during respiration is released into the atmosphere, while oxygen is used for other cellular processes. In the absence of sufficient oxygen, plants can switch to anaerobic respiration, where glucose is partially broken down to release energy in the absence of oxygen.

In conclusion, respiration is a characteristic process of all living cells, including plants. It occurs both during the day and night and is essential for the production of energy required for various cellular activities. While respiration in plants requires carbon dioxide, it is not directly involved in the formation of vitamins.