Which interaction type is described by diffusible, soluble signals rather than direct contact?

Which interaction type is described by diffusible, soluble signals rather than direct contact?

• A. Contact dependent interaction
• B. Biofilm formation
• C. Contact independent interaction
• D. Quorum sensing

Answer: (C)

Communication without direct cell-to-cell contact relies on diffusible, soluble signals that travel through the environment and affect nearby cells. This is called a contact-independent interaction. Quorum sensing is a classic example within this category, where signal molecules diffuse and accumulate with cell density to coordinate gene expression across the community. In contrast, interactions requiring physical contact or attachment—such as contact-dependent signaling or processes like biofilm formation that hinge on surface attachment—do not fit the description of diffusible, soluble signaling. So the described scenario best fits a contact-independent form of communication.

Communication without direct cell-to-cell contact relies on diffusible, soluble signals that travel through the environment and affect nearby cells. This is called a contact-independent interaction. Quorum sensing is a classic example within this category, where signal molecules diffuse and accumulate with cell density to coordinate gene expression across the community. In contrast, interactions requiring physical contact or attachment—such as contact-dependent signaling or processes like biofilm formation that hinge on surface attachment—do not fit the description of diffusible, soluble signaling. So the described scenario best fits a contact-independent form of communication.