Cellular totipotency
Cellular totipotency refers to the ability of a single cell to give rise to an entire organism. This concept was first proposed by German embryologist Hans Driesch in the late 19th century. It suggests that each somatic cell in a multicellular organism contains all the genetic information necessary to form an entire organism.

Mechanism of cellular totipotency
During the early stages of embryonic development, all cells in the embryo are totipotent. As the embryo develops, these totipotent cells undergo a process called cell differentiation, where they become specialized into different cell types with specific functions. This process is controlled by specific genes that are turned on or off in each cell, allowing them to acquire distinct characteristics.

Significance of cellular totipotency
The ability of cells to be totipotent is crucial for the development and regeneration of tissues and organs in multicellular organisms. It allows for the repair and replacement of damaged or lost cells, as well as the growth and development of an organism from a single fertilized egg. This property also plays a role in processes such as wound healing and tissue regeneration in adult organisms.

Applications of cellular totipotency
Understanding cellular totipotency has significant implications in the field of regenerative medicine. Scientists have been able to harness the totipotent properties of certain cells, such as embryonic stem cells, to generate various cell types in the laboratory. These cells can potentially be used for tissue engineering, organ transplantation, and treating degenerative diseases.

Conclusion
The ability of a living somatic nucleated cell to form the complete organism is referred to as cellular totipotency. This property is essential for the development, growth, and regeneration of multicellular organisms. Further research in this field holds great promise for the future of regenerative medicine.