# Unicellular Cell Signaling --- **Unicellular cell signaling** are special methods of [[cell signaling]] that [[microbe|unicellular organisms]] can use to communicate with each other or their environment. ## Quorum Sensing **[[Quorum sensing]]** is used by bacteria to sense when there are many of the same bacteria in one area. Some genes are pointless to transcribe if there are not enough bacteria around to make the product strong enough for a significant result. ## Two-Component Regulatory System The **[[two-component regulatory system]]** is a system that bacteria use to turn on or off genes in response to what they sense in their environment. ## Chemotaxis **[[Chemotaxis]]** is a way bacteria can sort of "smell their environment. They can actually sense all sorts of stuff, like sugars or poisens in their environment. This is very related to our sense of smell. ___