An organism needs a system of control and coordination for its survival in this word. The system of control and coordination is necessary in plants as well as animals (including human beings).
(i) The plants need carbon dioxide, water and sunlight. It is due to the presence of a hormonal system of control and coordination in plants that the stomata in leaves open to allow in carbon dioxide gas, the roots bend towards water and the shoots grow towards sunlight. It is also due to control and coordination that tendrils in plants having weak stems make them climb on to neighbouring supports.
(ii) In human beings, the system of control and coordination is needed for all our actions, thinking and behaviour. The human nervous system receives information from the surroundings, processes it and then responds accordingly. Our heart beart, breathing, reading, writing, cycling, dancing and various reflex actions are all because of the nervous system. The hormonal system (endocrine system) helps in controlling and coordinating activities like metabolism, development, reproduction and preparing our body to cope up with grave situations.
