Final answer:
The life of a cell in a healthy human being is best characterized by the concept of homeostasis, which is the balance or equilibrium that cells maintain to survive within varying external conditions by adjusting internal systems.
Step-by-step explanation:
In a healthy human being, a cell's life is best described by the philosophy of homeostasis. Homeostasis refers to the dynamic state of balance or equilibrium within the cell or the body, in which cells must constantly adjust systems to maintain a stable internal environment despite changing external conditions. This is essential for the survival of cells within the parameters that are compatible with life. For instance, maintaining optimal levels of blood pressure and blood oxygen content is crucial because deviations can lead to illness or even death.
Understanding this concept is further supported by the fact that cells undergo the process of reproduction to replace worn-out cells, contributing to the maintenance and repair of tissues which is a part of dynamic homeostasis. Every cell in a multicellular organism like a human is descended from a single ancestor cell, and even after full growth is achieved, cell reproduction continues to be vital for tissue repair and regeneration.
Therefore, the primary responsibility of each cell includes homeostasis, accommodating various structures and metabolic activities necessary for survival, and ensuring growth and reproduction. All of these are in line with enduring understanding 2.B. which states that growth, reproduction, and dynamic homeostasis require that cells create and maintain internal environments that are different from their external environments.