Exercise 2 Postlab

A cell that neither gains nor loses water when it is immersed in a solution is hypotonic to its environment. metabolically inactive. isotonic to its environment. dead. hypertonic to its environment.

isotonic to its environment.

Which of the following statements regarding diffusion is false? Diffusion is a result of the kinetic energy of atoms and molecules. Diffusion requires no input of energy into the system. Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated. Diffusion occurs even after equilibrium is reached and no net change is apparent. Diffusion is driven by concentration gradients.

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

Why is there a limit to the size of cells? Small cells experience efficient diffusion of oxygen and nutrients into the cells and waste products out of the cells due to their relatively large surface area to volume ratios. Small cells retain water and nutrients more effectively. Small cells experience efficient diffusion of oxygen and nutrients into the cells due to their relatively small surface area to volume ratios. Large cells require too much energy to survive. Small cells experience efficient diffusion of oxygen and nutrients into the cells and waste products out of the cells due to their relatively large surface area to volume ratios.

Small cells experience efficient diffusion of oxygen and nutrients into the cells and waste products out of the cells due to their relatively large surface area to volume ratios.

A bag made from dialysis tubing is filled with water and placed in a 15% sugar solution. A second bag, also made from dialysis tubing, is filled with 15% sugar solution and placed in water. Both bags are left for one hour and then weighed. What do you expect will happen? The first bag will lose weight and the second bag will gain weight. Neither bags will experience a net weight change. The first bag will gain weight and the second bag will lose weight. The first bag will lose weight due to osmosis, while the weight of the second bag will remain constant.

The first bag will lose weight and the second bag will gain weight.

A bucket is divided in half by a semi-permeable membrane. Equal amounts of fresh water and salt water are added to opposite sides of the membrane. What will happen? The side with the fresh water will increase in volume. There will be no change in the water on either side of the membrane. The fresh water will become salty as salt passes through the membrane. Water will move equally from both sides and neither side will increase in volume The side with the salt water will increase in volume.

The side with the salt water will increase in volume.

In the lab, you use dialysis tubing that is permeable to water, but not sucrose, to make an artificial cell. The "cell" is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur? Water will leave the "cell" Water will enter the "cell" Sucrose will enter the "cell" Sucrose will leave the "cell"

Water will leave the "cell"

If a red blood cell is placed in an isotonic saline solution, which will occur? Water will move into and out of the cell equally. Salts will move into and out of the cell equally. Salts will move into the cell from the surrounding solution. Water will move into the cell from the surrounding solution.

Water will move into and out of the cell equally.

In the process of osmosis, the net flow of water molecules into or out of the cell depends upon differences in the concentration of water molecules inside and outside the cell rate of movement of insoluble molecules inside the cell concentration of lipids in the cell membrane rate of molecular motion on either side of the cell membrane

concentration of water molecules inside and outside the cell

_______ is a shrinking of the cytoplasm away from the cell wall due to osmosis. recombination diffusion plasmolysis osmolarity

plasmolysis

Brownian motion is defined as: random movement of small particles due to collisions with molecules within a liquid directional movement of small particles due to collisions with molecules within a liquid directional movement of small organisms (such as bacteria) due to collisions with molecules within a liquid movement of small organisms in response to stimuli in a liquid

random movement of small particles due to collisions with molecules within a liquid

When placed in a hypotonic solution, an animal cell will neither gain nor lose water. experience turgor. swell and lyse. shrivel. lose water.

swell and lyse.

Osmosis can be defined as the diffusion of water across a membrane. the diffusion of nonpolar molecules. the diffusion of a solute into the cell. active transport of water across a membrane.

the diffusion of water across a membrane.

Plasma membranes are selectively permeable. This means that anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy. the plasma membrane allows some substances to enter or leave a cell more easily than others. cholesterol cannot enter the cell. plasma membranes must be very thick. glucose cannot enter the cell.

the plasma membrane allows some substances to enter or leave a cell more easily than others.

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference? the fact that plant cells are isotonic to tap water the relative impermeability of the plant cell wall to water the relative inelasticity and strength of the plant cell wall the expulsion of water by the plant cell's central vacuole the relative impermeability of the plant cell membrane to water

the relative inelasticity and strength of the plant cell wall