The macula densa cells respond to changes in na+ content of the filtrate. These cells senses changes in the sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood, for the purpose of altering the volume of blood and return blood pressure to normal.
Rubbing alcohol will float and corn oil will sink
It helps scientists improve on research and tests/examinations to understand the object a little more. For Example: The newer modified microscope helps zoom into harder to see microrganisms. So if technology changed then most of our scientific knowledge wouldve been mistaken this whole time. We wouldnt know many things if technology didnt exist.