It's not accurate to say that all cells have the same structure and functions. In fact, cells are incredibly diverse, with a wide range of structures and functions that allow them to perform specialized tasks within an organism.

Here's why:

* Cellular Specialization: Cells within a multicellular organism differentiate into different types, each with unique structures and functions adapted to their specific role. For example, muscle cells have elongated structures for contraction, nerve cells have long axons for transmitting signals, and red blood cells lack a nucleus to maximize oxygen transport.

* Evolutionary Adaptation: Over time, cells have evolved to suit the specific needs of their environment and the organism they belong to. This specialization has allowed for increased complexity and efficiency in living organisms.

* Diversity of Life: From bacteria to plants to animals, the vast diversity of life on Earth reflects the immense diversity of cell types. Each organism has its own unique set of cell types adapted to its specific environment and lifestyle.

While all cells share some fundamental characteristics (e.g., cell membrane, cytoplasm, DNA), their specific structures and functions vary significantly.

Therefore, it's more accurate to say that cells share a common ancestor and a basic set of essential components that allow for life, but they have evolved to become highly specialized and diverse in their structure and function.