In cells, the activity of enzymes is often regulated by other enzymes or molecules. Why
is this necessary?

What happens during interphase? (1)the nucleus grows to its full size. (2)the cell grows to its full size. (3)the nucleus divides into two nuclei. (4)the cell divides into two cells.

Archaebacteria use for movement. celia flagella pili cell walls

This is the interaction of two organisms where one is and the other is neither nor harmed.