i am not a master in biology but something i know that in plants the bark cells are impervious to gases and water as they have a chemical called suberin on their walls.

The Cell Master (Richard Hooke)

nucleic acids

stem cell are master cell. IE. they are further differentiated into different type of cell. Their fate is to form different type of blood cells and immune system cells

stem cells are undifferentiated cells that can change into the cells where they are needed. loads of cells die everyday and stem cells are used to replace them. there is now a treatment for all kinds of diseases where the body is to damaged to replace the cells. so a laboratory grows the stem cells and it is injected.

Stem cells currently have no use in the medical industry but around the year 2025 scientists are hoping to be able to master the art of being able to turn stem cells to a human's own cells which could cure cancer and many other diseases.