Lab 13 Diffusion and Osmosis in Eggs

glossary

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INTRODUCTION In this lab, you will learn about diffusion and osmosis. After completing this lab (and discussing osmosis and diffusion in class), you should be able to:

Define diffusion Define osmosis Analyze a given situation and predict whether diffusion or osmosis will occur Analyze a given situation and predict which directions particular molecules are likely to

move Explain the factors that affect the speed at which diffusion or osmosis occurs

Resources:Wikipedia is an excellent resource for finding definitions and examples. The ExploreLearning website (earlier this year, you obtained a username and password) has at least two Gizmos that can help you learn this process.

Complete the prelab before proceeding further.

http://www.biology-online.org/dictionary.aspmailto:rholsinger@sayreschool.org,dwheeler@sayreschool.orghttp://en.wikipedia.org/wiki/Diffusionhttp://www.explorelearning.com/

Lab 13 Prelab

Diffusion and Osmosis in Eggs

Name:

Pledge:

AUTHORIZED AID: You may discuss questions with classmates or other knowledgeable persons before

composing your OWN answer or you may use a source and cite it appropriately. (8 points)

1. Which types of cells have a cell membrane? (1)

Figure A

Figure B

2. Identify the figures above as either plant or animal cells. (2)

a. Figure A FORMDROPDOWN

b. Figure B FORMDROPDOWN

3. Which of the following functions is appropriate for the cell membrane? (1) FORMDROPDOWN

a. Controls the functions of the entire cell.

b. Makes protein.

c. Photosynthesizes.

d. Controls what enters and leaves the cell.

Use the following websites to read about diffusion and osmosis before answering the next set of questions:

Diffusion: http://en.wikipedia.org/wiki/Diffusion

Osmosis: http://en.wikipedia.org/wiki/Osmosis#Example_of_osmosis

4. True or False: Diffusion is the movement of molecules from areas of low concentration to areas of high concentration. (1) FORMDROPDOWN

a. If necessary, correct this statement to make it true:

5. True or False: Osmosis is a more specific name for the diffusion of water. (1) FORMDROPDOWN

a. If necessary, correct this statement to make it true:

6. When you've entered all your answers in the form fields, unprotect this document ("View", "Toolbars", "Forms" - then click on the padlock). Then, use your drawing tool to draw an arrow that points to the cell membrane in each of the cell figures above. (2)

References

"Typical Animal Cell." Biology. 12 Sept. 2006. National Research Council Canada.29 Jan. 2006 .

"Typical Plant Cell." Biology. 12 Sept. 2006. National Research Council Canada.29 Jan. 2006 .

dwheelerFile AttachmentLab 13 Prelab.doc

Lab 13 Diffusion and Osmosis in Eggs

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PROCEDURE

PaRt a Design an experiment to test which liquids pass into or out of the membrane of a chicken egg. Complete this section on your answer sheet and get approval to do it before setting it up.

Important information: Your egg will remain in each type of liquid for 24 hours. Your design must include a way to test how much liquid enters or exits the egg. You should also set up a data table to collect your data.

PaRt B You and your lab partner will have the opportunity to choose one liquid to test. Make sure you have your teachers permission to test the liquid you and your partner choose. Complete the Materials section of your answer sheet with the names of the liquids to be tested.

PaRt C You and your partner will be taking measurements of your egg every day and placing it in a different liquid daily. Make sure all data is documented on your answer sheet each day.

http://www.biology-online.org/dictionary.aspmailto:rholsinger@sayreschool.org,dwheeler@sayreschool.org

Lab 13 Answer Sheet

Diffusion and Osmosis in Eggs

Names:

Pledge:

Authorized Aid means you worked TOGETHER to complete this lab answers were discussed with one another before being typed, both of you participated in conducting the lab procedures, and any sources

or pictures are cited appropriately. (25 total points)

Experimental Design and Procedures

Use the research question to complete the experimental design.

Research Question: What liquids will pass through the membrane of a chicken egg?

a. Hypothesis (1):

b. Independent Variable (1):

c. Dependent Variable (1):

d. Control (1):

e. Constants (3):

1.

2.

3.

f. Methods (2) Make sure theyre detailed! Remember to include safety measures..

Materials

liquids to be tested (1): , , ,

egg

container

Parafilm

spoon

balance

graduated cylinder

soap

beaker brush

Results

1. Fill in the following data table (5 pts):

NOTE: All units should be metric (grams and/or milliliters)

Fill in the Independent Variable

Initial Weight of Fill in the Dependent Variable

(units)

Final Weight of Fill in the Dependent Variable

(units)

Difference in Weights of Fill in the Dependent Variable

(units)

Initial Volume of Fill in the Dependent Variable

(units)

Final Volume of Fill in the Dependent Variable

(units)

Difference in Volumes of Fill in the Dependent Variable

(units)

2. Insert graph(s) from Excel here:

NOTE: for help making graphs try: http://www-ed.fnal.gov/data/lifesci/data/tutorials/excel.shtml

Your graphs will be scored according to the following criteria:

a. The correct type of graph was chosen for the data presented. The graph was produced in Excel with appropriate major & minor divisions of the axes. Both axes are scaled properly (with divisions that are evenly spaced and make it easy for the reader to interpret). (1)

b. Both axes are labeled properly (IV & DV on appropriate axes) with words and units. (2)

c. Graph contains an appropriate title (one with both the IV & DV in it). (1)

3. Examine your data (both the data table and your graph).

a. According to your data, which liquids pass through the membrane (into the egg)? Be sure to explain how your data demonstrates this. (1)

b. Which liquids do not pass through the egg membrane (they may have caused liquid to leave the egg)? Be sure to explain how your data demonstrates this. (1)

4. Why did some liquids not pass through the membrane? (1)

5. Did you observe diffusion or osmosis in this lab? Explain your answer. (2)

6. What errors may have occurred in your experiment? (1)

dwheelerFile AttachmentLab 13 Answer Sheet.doc

Lab 13 Diffusion and Osmosis in Eggs

glossary

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HOmEwORkDont forget to do your homework!

REFERENCE

Holsinger, Rachel and Debbie Wheeler. Lab 13: Diffusion and Osmosis in Eggs. Sayre School: Lexington, KY. January 2007.

http://www.biology-online.org/dictionary.aspmailto:rholsinger@sayreschool.org,dwheeler@sayreschool.org

Lab 13 Homework

Diffusion and Osmosis in Eggs

Name:

Pledge:

AUTHORIZED AID: You may discuss questions with classmates or other knowledgeable persons before

composing your OWN answer or you may use a source and cite it appropriately. (15 total points)

Conclusions

1. Explain which direction the water and the salt will move (either into or out of the dialysis bag) in each of the following situations:

NOTE: Click here for the definition of solute. You may also find it helpful to draw a diagram of the dialysis bag in the beaker along with the salt concentrations to help you decide in which direction the water (solvent) or salt (solute) will move.

Another helpful resource: http://www.blobs.org/science/diffusion/index.shtml

a. A dialysis bag of 20% salt solution is placed in a beaker of 4% salt solution. (2)

i. Which direction will the water move? FORMDROPDOWN

ii. The solute (salt)? FORMDROPDOWN

b. A dialysis bag of 0% salt solution is placed in a beaker of 4% salt solution. (2)

i. Which direction will the water move? FORMDROPDOWN

ii. The solute (salt)? FORMDROPDOWN

c. A dialysis bag of 2% salt solution is placed in a beaker of 4% salt solution. (2)

i. Which direction will the water move? FORMDROPDOWN

ii. The solute (salt)? FORMDROPDOWN

d. A dialysis bag of 4% salt solution is placed in a beaker of 4% salt solution. (2)

i. Which direction will the water move? FORMDROPDOWN

ii. The solute (salt)? FORMDROPDOWN

2. Describe a situation in everyday life when diffusion or osmosis occurs. (2)

3. Making iced tea involves boiling water, adding tea bags to steep in the hot water, and, eventually, cooling the tea with ice. Would it be best to add sugar while the water was warm or after it had cooled? Explain your answer. (1)

4. You forgot to water your garden and notice that the plants have become wilted and limp.

a. Use the new vocabulary you've learned (osmosis, diffusion, etc.) to explain what has happened to the plant cells. (1)

b. What will happen to the plant cells if you now water the plants? (1)

5. A unicellular organism that normally lives in salt water is transferred to a beaker of fresh water. Explain what will happen to the cell. Use as many of the following words (appropriately) as you can: diffusion, osmosis, concentration, solute. (2)

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