A clinical study is conducted to determine the actions of an unknown test solution on red blood cell volume. One milliliter of heparinized human blood is pipetted into 100 milliliters of test solution and mixed. Samples are taken and analyzed immediately before and at 1-second intervals after mixing. The results show that red blood cells placed into the test solution immediately swell and burst. Which of the following best describes the tonicity and osmolarity of the test solution?
Tonicity and osmolarity are different. Osmolarity is merely another measure of solute concentration. Tonicity depends on the cell membrane and the solute and is determined by the behavior of the cells. The fact that red blood cells placed into the test solution gained volume (swelled) indicates that the test solution is hypotonic. In contrast, the osmolarity of the test solution cannot be determined by the behavior of the cells.
Hypeonic; could be hyperosmotic, hypo-osmotic, or iso-osmotic
Hypeonic; must be hyperosmotic or hypo-osmotic
Hypeonic; must be iso-osmotic
Hypotonic; could be hyperosmotic, hypo-osmotic, or iso-osmotic
Body fluid compaments