On the geological time scale, the early and late are subdivisions of the cretaceous period.

The correct answer is:

C)epochs

*the answer was not A.) ages, it was incorrect for me*

cell regulation is conducted by special proteins.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.