What keeps an organism alive?
Even when you are sitting still, your body is busy. Cells use energy, exchange materials, and remove waste. The basic activities that maintain an organism are called life processes.
Nutrition supplies materials and energy sources. Respiration releases usable energy from food. Transport moves substances where they are needed. Excretion removes metabolic wastes.
These activities work together. Food alone cannot sustain a cell unless nutrients reach it and the cell can release energy from them.
KEY TAKEAWAY
Life processes maintain living organisms, even when there is no visible movement.