In an experiment to see if having a nurse come three times to visit the homes of newborn babies reduces doctor visits, what is the independent variable?

Explain two reasons you think it is important for scientists to search for new ways to treat cancer

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.

Molecules like glucose and amino acids are not lipid soluble, so cannot cross the cell membrane by simple diffusion. instead, they are shuttled across by carrier proteins in the membrane from high to low concentration. does this process require energy from the cell? this is an example of what type of molecular movement?