Funding sponsored by:
www.qad.com
Experimental Design:
Osmosis & the Chicken Egg
Click here to view the project resources.
Project Description: This guided inquiry lab takes the classic Osmosis Egg Cell Lab to the next level. Student teams design an experiment to test their claim (hypothesis). Throw away those boring lab reports! Teams create a website to showcase evidence (experiment results). Student teams present their websites to the class.
How it works:
1. Formative Assessment: Ask students what would happen to a shell-less egg if you soaked it in water. Students write their claim (hypothesis). Students write their reasoning (explain why they think this. Students usually have difficulty with this.)
2. Introduce other liquids and have them write claims & reasoning for each.
3. Pre-lab: show students how to measure circumference using a string, ruler, and plastic ball.
4. Pre-lab: show students how to measure weight using a scale and plastic ball.
5. Have student teams design an experiment to test their claims. Teacher: try not to give answers. Students will want you to tell them if they are "doing it right." Answer their question with a question or ask another student in the team what they think. You might say "How could that experiment be made even better?" or "What will that experiment tell you?" or "What kind of data will you collect?"
6. Students carry out tests and record their evidence (data).
7. Have students review evidence and check their reasoning. They may want to revise it.
8. Students create team websites to showcase their evidence.
9. Student teams present their evidence and reasoning. This is where you assess.
10. Class discussion: why did the egg shrink or swell? Ask for student ideas. Introduce the concept of osmosis.
See my website at sites.google.com/site/teachnetinnovator2012/ for the docs.
Assessment: I assess projects when teams present their websites.
Standards: Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations.
Estimated Number of Class Periods for Students To Complete Unit: 10 or More Class Periods.
Software or Materials Used: Google Form. Website to post link to Form such as Moodle (available through SBCEO), Edmodo, Google Sites, Weebly. Computer assess for students. Internet connection, LCD projector. Lab materials: chicken eggs, various solutions such as vinegar, corn syrup, sugar water, salt water, cornstarch solution, food coloring, scale (preferably electronic) string, rulers, plastic cups, wax pencils. Round objects of the same weight and size for prelabs (such as plastic balls)..
Keywords: biology, osmosis, computer, technology, website, inquiry, Google, Form, project, design
The Students: This unit is designed for all middle school students.
Overall Value: This project takes a cookbook type science experiment and turns it into an inquiry project. The key to good inquiry is for the teacher to relinquish the role as "sage on the stage," the one with all the answers. When students ask you a question or try to get their thinking validated by you, you might try saying "Good question, what do you think?" Or ask another student what they think. Also, don't just accept correct answers and don't tell them when they are wrong. Ask students to explain their ideas. You might say "Interesting idea, why do you think that? What evidence do you have for that?"
Subject Area: Science
Grade Levels: Grade 7
Tips for the Teacher:
Have fun and let me know how it goes!
Find resources on my website. Check out my blog at rickardbiology.blogspot.com.
