I. Curricular Framework

Concept:

Functions

Essential Question:

How is the structure and function of a cell like that of a city?

Bridge:

Structures

Content:

Cell Anatomy

Outcomes:

II. Standards Aligned

III. Instruction and Assessment

1. Connect: Connecting to the Concept Experientially

Objective: To have students personally realize that all living things, including themselves, are made up of cells.

Activity: The students begin this unit by looking at the basic structure of their bodies by doing the classic "cheek cell" lab. Having reviewed the parts and techniques of using a light microscope, the students gently rub the inside of their cheeks with toothpicks. They then make wet mounts and stain their specimens with methylene blue. They should see flat, irregularly roundish squamous cells with lavender cytoplasm and dark purple nuclei. They will also see strange foreign particles and even bacteria. The students should be provided with the materials necessary to draw what they see and color it. (It proves useful to provide students with a worksheet which has circles approximately 6cm in diameter representing the microscope field.)

Assessment: Attentiveness of the class to the activity, success in finding their cheek cells and excitement at looking at a piece of themselves.

2. Attend: Attending to the Connection

Objective: To have the students reflect on the experience of seeing some of their own cheek cells; to have them realize that in that dark, purple, central spot are all the directions for making them uniquely themselves.

Activity: Students are given the opportunity to reflect on a series of guiding questions, first independently and then as a class. Sample questions would include: What did the cells look like? Were they all exactly the same? How big are your cells? Do you think all your body cells look alike? What are some special types of body cells you know about? Did you see anything besides your cheek cells on the slide? Do you think bacteria are cells? Why is it appropriate to define a cell as a building block? Does each person have a structure in common? How are we the same? How are we different?

Assessment: Quality and appropriateness of student answers.

Assessment, Phase One, Level of Engagement, Fascination:

3. Image: Creating a Mental Picture

Objective: The students will identify some of the functions of the organelles by working with the metaphor of the cell as a city.

Activity: Students have only seen cytoplasm and a nucleus when they looked at their cheek cells. For homework, they are asked to take an imaginary trip into the cell. They are told that the cell is like a city. The assignment asks them to identify the things that every functioning city needs and then to record those things in drawing or in words. The next class begins with generating a composite list. Then the teacher generates some thought questions: What would happen in a city where there were no water reservoirs; no garbage trucks; no transport system? Can you see why a cell would need similar structures?

Assessment: Quality of student responses: their ability to identify all the critical structures that keep a city functioning and to take the metaphorical leap to see that a cell would need similar structures and functions.

Assessment, Phase Two, Seeing the Big Picture:

4. Inform: Receiving Facts & Knowledge

Objective: To provide the students with the names, structures and functions of the organelles of the cell and to show their universality as well as the link to specialization.

Activity: Using electron micrographs of real cells, a 3D model, and the metaphor that links the organelles to the parts of a city, the teacher presents the STRUCTURES and FUNCTIONS of the cell's organelles.

Assessment: Quality of students' notes; their ability through verbal checking to identify organelles and their functions.

Assessment, Phase Three, Success with Acquiring Knowledge:

5. Practice: Developing Skills

Objective: To confirm the students' ability to visually identify both drawings and electron micrographs of cell organelles; to check that they can verbally identify the organelles and match them with their unique and yet interrelated function in the cell; to have the students identify examples of protozoa, plant and animal cells under the microscope.

Activity: For this octant, students 1) complete a worksheet where they label the parts in a drawing of the cell, 2) take a quiz of simple matching columns for structure and function, 3) participate in a practice review in which the teacher conducts a "CELL CITY TOUR" (this is one of the highlights of the year. The teacher can get dressed up in a slicker, galoshes, umbrella and carry a picket sign that says 'CELL TOURS." She/he greets the students at the door and welcomes them into a cell. Tacked up around the room are simple, large, colorful drawings typically used to designate the difference organelles. Members of the "tour group" are invited to come up and describe in detail a random "site" on the tour), 4) look at microviewer slides of real cell organelles, 5) bring in samples of water, plants, etc. that they chose to look at under the microscope.

Assessment: Quality of student involvement in the activities: their success in labeling the diagram and matching structures and functions; their enthusiasm and accurate, active participation in the "Tour"; their ability to draw and identify organelles on the microviewer slides.

Assessment, Phase Four, Success with Acquiring Skills:

6. Extend: Extending Learning to the Outside World

Objective: To have the students own and "play with" the functioning parts of the cell.

Activity: Working in approximately three groups of eight, the students plan a creative way to act out the parts of a cell. Essentially, they are designing one more metaphors in which they act out their understanding of the cell and its organelles. They can write a play and get dressed up to match the functions of the organelles, or they can write a rap song or a long rhyming poem, or even become a living model.

Assessment: Creativity and participation of the group members.

7. Refine: Refining the Extension

Objective: To have the students check their productions for technical accuracy.

Activity: Students confer with other group members and the teacher to check the accuracy of their ideas and to hone the presentations.

Assessment: Faithfulness of the creative metaphors to the structures and/or functions of the organelles.

8. Perform: Creative Manifestation of Material Learned

Objective: Have the students share what they have learned about the cell and its organelles and "teach it" in yet another way.

Activity: Groups present their "Cell Productions" for the rest of the class.

Assessment: Quality of productions; enthusiasm and enjoyment of the performers and audience.

Assessment, Phase Five,Performance, Creative Use of Material Learned: