Nutrition.
To sustain adverse conditions and its utilization during active period of growth
Energy,Growth and Repair.
it means that get required energy(vit,min,etc) from it n use roughage to help in keeping ur bowl healthy.in lay man's language food utilization means to fulfill ur apettite.
Assimilation is the process of utilization of food by the body.
Food.
Food has various nutrients such as Carbohydrates, Fats, Proteins, Minerals,Vitamins.Each Nutrient contains energy,growth and many more.So for energy and growth and also for protection against diseases we need FOOD
All Organism need Food to promote growth and for energy.
solar energy
body needs food for growth, energy and repair
So that they will have energy to use for their growth and development.
Assimilation
In food, there are many macro molecules. Among them, the main contribution towards the energy is given by the carbohydrates and fats. For the development, growth and repair our cell needs proteins and other micro nutrients like vitamins and minerals.