Please clarify your question. You're asking about how scientists grow cells, but you haven't specified the environment or context.

Do you want to know:

* How scientists grow cells in a lab setting? This would involve discussing cell culture techniques, media, and incubators.

* How cells grow in a natural environment? This would involve discussing cell division, differentiation, and the role of nutrients and other factors.

* How scientists grow specific types of cells? This would involve discussing the specific requirements for different cell types, such as stem cells, cancer cells, or bacteria.

Please provide more detail so I can give you a helpful answer.