Exploring Selective Permeability with Dialysis Tubing

What is selective permeability?

• A membrane's ability to allow all substances to pass through.

• A membrane's ability to allow only water to pass through.

• A membrane's ability to allow some substances to pass through but not others.

• A membrane's ability to block all substances from passing through.

What is the purpose of using dialysis tubing in the experiment?

• To demonstrate the impermeability of membranes.

• To show how all substances can pass through membranes.

• To demonstrate selective permeability.

• To filter out all substances from a solution.

What substances were placed inside the dialysis bag?

• Iodine and starch

• Fructose and glucose

• Fructose and starch

• Starch and glucose

What was the initial color of the starch-fructose solution inside the bag?

• Purple

• White

• Yellow

• Black

What indicates that iodine diffused into the dialysis bag?

• The solution in the test tube turned purple.

• The solution in the cup turned purple.

• The solution inside the bag turned white.

• The solution inside the bag turned purple.

What process is primarily at work in this lab experiment?

• Active transport

• Filtration

• Diffusion

• Osmosis

Why didn't the starch diffuse out of the dialysis bag?

• Because the concentration gradient was not high enough.

• Because the starch reacted with iodine outside the bag.

• Because the bag was permeable to starch.

• Because the starch was too large to pass through the pores.

What happened to the iodine once it entered the dialysis bag?

• It diffused back into the cup.

• It chemically reacted with the starch.

• It remained unchanged.

• It turned into fructose.

Why is the color of the iodine solution in the cup lighter after the experiment?

• Because the iodine evaporated.

• Because the iodine was absorbed by the glass.

• Because the iodine diffused into the bag and reacted with starch.

• Because the iodine was diluted with water.

Why is selective permeability important for living systems?

• It allows all substances to enter the cell.

• It allows cells to control what enters and exits, maintaining homeostasis.

• It allows only water to enter the cell.

• It prevents any substances from entering the cell.