Which word describes the act of generating and separating substances from cells or bodily fluids?

The act of generating and separating substances from cells or bodily fluids is best described by the word "secrete." This term is often used in biological contexts to refer to the process by which cells produce and release substances, such as hormones, enzymes, or other molecules, into bodily fluids or cavities. Secretion is a crucial function in various physiological processes, allowing cells to communicate with one another and to influence different systemic functions within an organism.

The other options do not accurately capture this meaning. While "excrete" refers specifically to the process of eliminating waste materials from the body, such as through urine or feces, "isolate" pertains to separating something from a larger group, and "conceal" means to hide or keep something from being seen or known. These terms do not imply the active generation and release of substances in the same way that "secrete" does.