Question

water diffuses down its concentration gradient by osmosis, which is a passive transport process. an isotonic solution has the same concentration of membrane - impermeable solutes as normal extracellular fluid. in contrast, a hypotonic solution has a comparatively lower concentration of membrane - impermeable solutes and a higher concentration of water, while the opposite is true of a hypertonic solution. water always moves from higher to lower water concentration until equilibrium is reached. the movement of water can alter the volume or pressure of a cell, which is referred to as tonicity. a cell that is immersed in a hypertonic solution loses water and shrinks, a process called crenation. a cell that is immersed in a hypotonic solution takes in water and swells. if the concentration difference is large enough, the movement of water into the cell can cause the cell to rupture, a process called lysis.

1. physiological saline is a solution containing 0.9% nacl. a cell in 1.5% nacl is in a(n) ___ solution.

○ isotonic
○ hypertonic
○ hypotonic

1. the movement of water by osmosis is always from a ___.

○ low to high solute concentration
○ high to low solute concentration

Explanation:

1. A hypertonic solution has a higher concentration of membrane - impermeable solutes compared to the cell's interior. Since 1.5% NaCl has a higher salt (solute) concentration than the physiological saline (0.9% NaCl) and the cell's normal environment, the cell in 1.5% NaCl is in a hypertonic solution.
2. Osmosis is the movement of water from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration).

Answer:

1. B. hypertonic
2. B. high to low solute concentration