What is the substance directly involved in cellular communication within the human body

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.

The transport tubes for food coming down the plants are called?

This is collection of data made by comparing objects in standard units. in science, the units are metric.