Biological Noise and Its Origins Biological noise refers to the random fluctuations in molecular processes within cells, leading to phenotypic variations among genetically identical cells in the same environment. It is generally categorized into two types: intrinsic noise, which arises from the inherently stochastic nature of biochemical reactions (such as random bursts of mRNA transcription), and extrinsic noise, which stems from cell-to-cell differences in shared cellular resources, like ribosomes, polymerases, or cell cycle stages.

Deterministic vs. Stochastic Modeling Traditional deterministic models use ordinary differential equations (ODEs) to describe reaction rates. While useful for large-scale systems, ODEs fail to capture the dynamics of mesoscopic cellular environments where key molecules exist in very low copy  ...