1. How is osmosis defined?

A. as active transport

B. as requiring a transport protein

C. as an example of facilitated diffusion

D. as diffusion of water through a selectively permeable membrane

2. Which of the following describe the role a biochemical pump plays in active transport?

!! Choose all that apply !!

A. It helps a cell accumulate a relatively high concentration of a molecule.

B. It helps move materials across the membrane against the concentration gradient.

C. It helps large molecules that do not normally cross the cell membrane to enter or exit cells.

D. It helps move water more quickly across the membrane.

3. Using your knowledge of osmosis, explain why you should not drink large quantities of ocean water by answering the following:

1) Is ocean water hyper, hypo or isotonic to your body? Explain why.

2) Based on your answer to part 1, what will this type of solution ultimately do to the cells of your body?

Answer using 2 to 3 complete sentences.

4. The paramecium is a fresh water protozoan. The salt content of its cytoplasm is greater than that of the surrounding medium. Using this information, answer the questions below:

1) Does water tend to enter or leave the paramecium? Is this process of passive or active transport? Explain.

2) What process does the paramecium use to expel water? Is this a process of passive or active transport? Explain.

Answer in 2 to 3 sentences.