Cell Differentiation Is The Spice Of Life
Lesson 6 of 7
Objective: SWBAT develop a claim describing the importance of cell differentiation and provide evidence to support their claim based on observations made in the lab, as well as supporting research pertaining to the structure and function of various types of cells.
Students will label their paper, "Animal Cells vs. Plant Cells" and record 3 facts from this short video clip that discusses the differences between plants and animals even if they are both eukaryotic cells. Students notes may vary, but as long as the facts are accurate there are no right or wrong answers for this anticipatory activity. The teacher will randomly select three volunteers to share their facts to create the foundation for today's lesson to build upon through the microscopic investigation of plant and animal cells.
The teacher will show the class a review slide of the Venn Diagram that depicts the similarities and differences between plant and animal cells. This graphic organizer was originally presented in the lesson, "Art for Cell" to the students as a conclusion to the "Structure and Function of the Cell Lecture Notes".
Students will pair-share the most significant differences between plants and animals in a short one-minute conversation which will serve as a review and connection to prior knowledge to prepare students for today's experiment.
Students will need to recreate the Venn Diagram in the conclusion section of their lab summary in an effort to retain the similarities and differences between plant and animal cells.
Sample of Student Work -Cell Venn Diagram - This student has taken the time to identify similarities and differences between plant and animal cells. The students were encouraged to use their textbook and lecture notes as a reference to ensure all details were identified in this activity.
Student Inquiry - Students will be able to browse the extensive class set of slides and select two prepared slides based on their personal interest. Slide samples include human blood smears, osteocytes (bone cells), cardiac cells, or plant stems and leaves to name just a few. These types of prepared slides can be purchased from any science supply catalog in preparation for this activity. Students enjoy the autonomy to select their own slides and the freedom to learn more about topics that support their personal interests. To learn more about this strategy, please view the Reflection for this section.
Each student will receive an Investigation Guide to record all of their observations, critical thinking, and research throughout this inquiry activity. As students-pairs view their selected slides under the microscopes, they will diagram their field of view and attempt to identify the structures that they are able to observe. Students will work in pairs in order to collaborate and assist one another in the challenge of locating the specimen sample and focusing the microscope so that the cell structures/organelles can be viewed to the best of our ability. In order to supplement student knowledge of their slide samples, the class set of laptops will be available to provide students the opportunity to research what the cell sample looks like under higher magnification and/or a more effective staining technique. Students are also encouraged to research the function of the cell types in an effort to make the connection between structure and function for their selected samples. Students will need to develop a statement that explains the relationship between their observations and the specific function of the cell type.
Cell Differentiation Sample #1: This student worked really hard to identify the small details of the cells that she selected to study. The sketches of the cells are above and beyond my expectations. The quality of work and depth of thought by this student made this assignment a success.
Cell Differentiation Sample #2: This student had fun with this assignment, but remained at a more superficial level of understanding based on her selection of plant versus animal cells. The student did express their appreciation for the opportunity to learn and really liked to use the microscope.
Basic Investigation - If your student population will benefit from differentiated instruction, this lab investigation is a more basic approach to introducing the differences between plant and animal cells. Students will need to review the basics of staining techniques and how to prepare a wet-mount slide before the start of this activity. This lab is a more traditional approach of preparing and viewing cheek cells, onion cells, and elodea (water plant) cells at lower level of Webb's Depth of Knowledge. In the past, I have used this lab activity as an introduction to our Cell Biology Unit and the Student Inquiry Lab as a review before the assessment.
Students will use their microscope observations of varying cell types, their lecture notes about cell organelles, and the diagrams of cells from their textbook to draw evidence to make a claim that cell differentiation is essential to life as we know it! Students will record their evidence and claim at the bottom of their cell illustration sheet that was completed in the section above. Students may need some encouragement to get started on such a "big" concept as cell differentiation. Some possible teacher prompts may include:
- Why don't all cells in our body look the same?
- Did you notice that the different samples of plant cells looked different?
- How do these differences allow the organism, plant or animal, sustain their daily functions and remain alive?
- Would you be able to survive if your body only had one type of cell?
- How does cell differentiation enable you to do all of the things you do each day?
Remind students that they need to cite actual evidence that supports their claim:
- My observation of the blood cell and bone cell showed that even though both cells came from the human body they appear way different because they have different roles in our body.
- Even though both plant cells appeared green, their structure was different because the plants had adapted to survive in different terrains.
Cell differentiation is a wonderful opportunity to introduce evolution and let your students know what they will be studying in later units!
Close - A Final Analogy
As a final review of today's lesson, students will use their prior lecture notes and work from today's lesson to compare each cell organelle to a different part of a city. Students will need to create at least 10 analogies that compare the plant and animal cells to a city. Encourage your students to be creative and think outside of the box
- For example, the nucleus of a cell is like City Hall because it runs the city and makes the rules for how the city functions.
Sample of Student Work - The Cell is Like A . . . this student was able to think outside of the box and compare the cell to a city. I appreciated her attention to detail and her ability to connect our study of the cell to her experiences in our town.