The correct answer is option b. They receive instructions in their DNA.
The DNA (deoxyribonucleic acid) or the genes present in the cell guides the fate of the cells during the process of cellular differentiation in the embryonic life of the multicellular organism. The signaling molecule change the genetic expression changes, by which the cells are differentiated.
The only independent variable in this experiment is the amount of nitrogen Sarah uses. All of the other variables are dependent on other factor and processes, but Sarah controls the amount of nitrogen that she uses for each plant.
They help absorb nutrients <span />
The correct answer is "<span>they can develop into most types of human cells".
Stem cells are cells that are undifferentiated to what function they may serve, depending on the tissue where it will develop in to. In the context of brain tissue implants, these stem cells can develop into brain cells or nerve cells or neurons which comprises the functional brain tissue; this is clinically significant as neurons are not capable of replacing themselves if damaged.</span>