Final answer:
Cells grown in culture outside the body are called 'c) “in vitro” cells' and are a crucial tool for cell and molecular biologists. 'In vitro' refers to cells growing in a controlled artificial environment using culture media.
Step-by-step explanation:
Cells grown in culture outside the body are called c)“in vitro” cells.
They have become an essential tool of cell and molecular biologists.
The term '“in vitro”' literally means 'in the glass' and refers to the fact that these cultures are grown in laboratory dishes, flasks, or other vessels.
When a cell is removed from an organism and placed into this artificial environment with culture media that provides necessary nutrients, support, and conditions it requires, the cell can grow and multiply.
The culture media typically includes physical media like a solid surface such as plastic or glass for cells to attach to and grow, as well as chemical media that contains the appropriate nutrients and hormones.
A primary cell culture refers to the initial growth of these cells in a culture vessel, when the cells tend to grow until they form a monolayer and become too dense, leading to contact inhibition.
To continue growth beyond this stage, cells may need to be transferred or passaged to fresh media, creating what is known as a secondary culture.
Alternatively, immortalized cell lines can be developed that do not experience contact inhibition and can be continuously subcultured.
For example, cancer cells, which are often the subject of in vitro studies, can be grown as continuous cell cultures that do not exhibit contact inhibition and can grow indefinitely if given the right conditions.