The Incredible (Non-Edible) Egg Lab!
Background:
Eggs are very useful for modeling osmosis because you can remove their shells and pretend that they are
cells. Soaking an egg in white household vinegar for 48-72 hours dissolves the shell and hardens the outside
of the egg white, leaving a semi-permeable membrane to the inside of the egg. Using eggs as models for
cells, you will design an experiment to answer the following question:
How do hypertonic, hypotonic, and isotonic solutions affect the mass of cells?
Materials to start add to it as you see fit, including all materials used in the lab:
□ 3 eggs
□ Household vinegar
□ Digital scale and weighing plates
□ 3 graduated cylinders (name the size you use)
□ A variety of solutions (name your solutions)
□ Masking Tape
□ Sharpies
Originality
Prior to your lab being considered proficient, it must be uploaded on turnitin.com. Any websites used as
research, must be included as an in text citation and the URL at the end of the report in a work cited section.
Wikipedia will not be accepted as a resource. All parts of the lab must be in your own words.
Guidelines for Writing Egg Lab Report
I. Include a Title – should identify the goal of the lab and specific organism(s) involved.
II. State the Problem – give a question that you’re trying to answer or identify the problem you’re trying to solve with the
experiment that you’re doing.
III. Hypothesis – Stated in “If …... then ……., because” format. Include a logical reason for choosing one solution over the
others to be more successful at demonstrating the lab. (3 hypotheses, one for each egg)
IV. Background Information – provide a paragraph of background information for all key concepts and processes involved.
Your background information should cover the following elements –
What is the purpose of the lab?
- How are diffusion, osmosis, and the cell membrane connected?
- What is osmotic pressure?
- What is the difference between hypertonic, hypotonic, and isotonic solutions? What affect do they have on a cell and
its size/shape?
- How do solute and solvent concentrations play a role in osmotic pressure? Discuss the movement of the water and
concentration gradient.
- Why is using the egg a good example of a cell in this experiment?
- Why is the egg first kept in vinegar before performing the experiment?
V. Materials – List all materials used. See list above. .
VI. Procedures – List procedures in a set of steps in the order necessary to complete the lab. Procedures should be clear enough
that someone could use them to reproduce the same experiment. Use concise language, be thorough. Do not use personal
pronouns (he, she, them, they, etc.) At the end of your procedures list the Manipulated Variable, Responding Variable and
Controlled Variables.
1.
2.
Data – record quantitative and qualitative forms of data. Use charts, tables, diagrams to organize and display data. Label
numbers with correct units.
Graph- illustrating data (bar or line), with X and Y axis and title.
VII. Analysis and Conclusion –. A good conclusion can answer the
what, how and why of the lab.
The conclusion should be written out in paragraph form and should include the following parts. Use the italicized words as guides
to begin your statements.
1. The purpose of this experiment was to ... (Check your purpose)
2. To achieve this purpose we ... (What did you do in the lab? Be very brief)
3. My hypothesis was ... (discuss each hypothesis)
4. The data does/does not support my hypothesis. My experiment showed that ...(your results here) (Use data from your
experiment to explain why or why not your hypothesis was proven or not)
5. An explanation for our results might be ... (Use concepts covered in class, discuss how the water moved, type of
solution (hyper, hypo, iso), type of osmotic pressure the egg was (hypo, hyper, iso), discuss solute/solvent concentrations,
discuss data patterns
VIII. Error Analysis – Evaluate the validity of the results? What have you done to ensure that the results could be repeated or
give you a valid result? (Include at least 3 ideas) Address the issue of number of trials and how it affects the validity of your
experiment. If you don’t think your lab was valid – give reasons why. Consider what might have not worked well in the lab.
Explain how potential errors would influence your final result – be specific
The error analysis should be written out in paragraph form and included the following parts. Use the italicized words as a guide to
begin your statements.
1. Potential sources of error that could have effected our results were…….. (Discuss how they effected your data)
2. To ensure valid results in the lab we … (discuss your validity measures)
3. Our lab results were/were not valid because… (Discuss factors that affected your results. What affect did the error have
on your data? Be specific.)
4. Address the number of trials and how it affects the validity of your results.
5. Our results could be improved if we ... (Suggestions for improvement on the lab [better equipment is not a valid
suggestion], OR how could you take this experiment further, what would you like to investigate more?).
6. I could take this experiment further by…(future research or unanswered questions
Miscellaneous:
Type your report. Double space between sections, single space within a section.
Use the headings listed above for each section.
Edit / Proof-read your work.
Always turn in a neat, well organized report – on time.
Important Dates:
November 14th/ 15th – lab handed out, experiment set up
November 16th/ 17th – Final data collected, computer lab day
November 18th- Computer lab day
November 21st/ November 22nd- Lab report Draft Due, Peer Edit in class, computer lab time for changes
November 28th/ November 29th- Final draft of lab report due at the beginning of your class period, turn in
peer edit and stamped draft for points
December 2nd- Lab report due on Turnitin.com by 3pm, no lab on turnitin.com = a “0” for lab
Turnitin.com Class Enrollment
Period
Class ID
Class Password
Period 1
Period 2
Period 3
4556842
4556843
4556844
biologyrocks
biologyrocks
biologyrocks