Which term refers to the property that helps molecules stick together within a liquid?

Cohesion is the property that allows molecules of the same substance to stick together within a liquid. This phenomenon is primarily due to intermolecular forces, such as hydrogen bonding in water molecules. When water molecules attract each other, they create surface tension, allowing them to resist external force and maintain their shape.

Cohesion is essential in many biological processes; for example, it contributes to the way water moves through plants in a process called transpiration. It also plays a significant role in maintaining water's characteristics as a solvent and its ability to support life.

The other options involve different properties or concepts. Adhesion refers to the attraction between molecules of different substances, such as water sticking to the surface of a leaf. Solutes are substances that are dissolved in a solution, and enzymes are proteins that accelerate chemical reactions within cells. While relevant in the study of biology, they do not describe the sticking together of similar molecules within a liquid.