Why do scientists need to be able to study cells in a laboratory environment?

They are able to understand cells well. This they do by controlling particular variables of the cell and observe the effects on the cell. This allows them to understand how the cell works. The significance of this is that it is now possible to design drugs to particular diseases that affect humans.

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.