Why do organisms need both processes?

Natalie had random hand movements when she was two months old. when she was six months old, she used to grab a block with her whole hand. now at the age of ten months, she can grasp the same block with her thumb and forefinger. this sequence of growth in her hand and finger movements is according to the pattern.

In which case would a scientist choose to use a dissecting microscope rather than a compound microscope

Which group of molecules are targeted by the kinases in order to control this movement