Organisms Need Food for Energy

Food is essential for all organisms as it provides the necessary nutrients and energy required for growth and maintenance of their bodies. It is the primary source of energy for all living things, and without it, organisms would not be able to survive.

1. Energy Source:
- Food serves as a source of energy for organisms. The chemical energy present in food molecules, such as carbohydrates, proteins, and fats, is converted into a usable form of energy called ATP (Adenosine Triphosphate) through cellular respiration.
- ATP is the energy currency of the cell and is used for various metabolic processes, including growth, repair, movement, and reproduction.

2. Nutrient Supply:
- Food provides essential nutrients that are required for the proper functioning of the body. These nutrients include carbohydrates, proteins, fats, vitamins, minerals, and water.
- Carbohydrates are the main source of energy, proteins are necessary for growth and repair, fats provide energy and insulation, vitamins and minerals are essential for various bodily functions, and water is vital for hydration and overall functioning of cells and organs.

3. Growth and Development:
- Organisms need food to grow and develop. The nutrients present in food are utilized by cells to synthesize new molecules, build tissues, and repair damaged cells.
- During growth, organisms go through various stages, and the energy and nutrients obtained from food support these processes.

4. Maintenance of Body Functions:
- Food is required for the maintenance of body functions. Every organism has metabolic processes that occur continuously to sustain life.
- These processes include breathing, circulation, digestion, excretion, and movement. All of these activities require energy, which is obtained from the food we consume.

Conclusion:
Food is necessary for all organisms as it provides energy and essential nutrients required for growth, development, and maintenance of the body. Without food, organisms would not be able to carry out vital functions and sustain life. Hence, the correct answer to the given question is option C - Food.