Pi (π) is a mathematical constant that represents the ratio of the circumference of a circle to its diameter. It is an irrational number, meaning that it cannot be expressed as a simple fraction, and its decimal representation goes on infinitely without repeating.

Unlike Fibonacci numbers, Pi is not typically associated with patterns or structures found in living organisms. However, Pi does appear in some mathematical models used to study biological systems, such as:

1. DNA: The structure of DNA, which contains the genetic information of living organisms, can be modeled using mathematical curves called helices. The helix has a pitch angle that is related to Pi.
2. Protein folding: Proteins, which perform many functions in living cells, must fold into specific shapes to carry out their roles. The energy landscape of protein folding can be modeled using equations that involve Pi.
3. Ecology: Some models used to study the growth and interactions of populations of organisms, such as predator-prey dynamics, involve mathematical equations that include Pi.
4. Neuroscience: Some models used to study the firing patterns of neurons in the brain involve equations that include Pi.

In summary, Pi is not commonly associated with patterns or structures found in living organisms, but it does appear in some mathematical models used to study biological systems.