Question

If a cell has less concentration of solutes inside than outside, it is in a(n) ___________ environment.

		Hypertonic
		Isotonic
		Hypotonic
		Mesotonic

Answer 1

ans:Hypotonic

A hypotonic solution has a lower concentration of solutes than another solution. In biology, a solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated. For cells without a cell wall such as animal cells, if the gradient is large enough, the uptake of excess water can produce enough pressure to induce cytolysis, or rupturing of the cell. When plant cells are in a hypotonic solution, the central vacuole takes on extra water and pushes the cell membrane against the cell wall.

If the extracellular fluid has lower osmolarity than the fluid inside the cell, it’s said to be hypotonic—hypo means less than—to the cell, and the net flow of water will be into the cell.

The ability of an extracellular solution to make water move into or out of a cell by osmosis is know as its tonicity. Three terms—hypotonic, isotonic, and hypertonic—are used to compare the osmolarity of a cell to the osmolarity of the extracellular fluid around it.

In the reverse case, if the extracellular fluid has a higher osmolarity than the cell’s cytoplasm, it’s said to be hypertonic—hyper means greater than—to the cell, and water will move out of the cell to the region of higher solute concentration

In an isotonic solution—iso means the same—the extracellular fluid has the same osmolarity as the cell, and there will be no net movement of water into or out of the cell.