Unicellular organisms have receptors that have evolved to react to external dangers, along with self-protective, responsive mechanisms made to increase the likelihood of survival in the face of chemical and physical forms of attack or danger.
单细胞生物具有受体，它们已经进化到能够对外部危险作出反应，同时还有自我保护的反应机制，以增加在面对化学和物理形式的攻击或危险时存活的可能性。