• Identification of structures and functions of cell organelles will be assessed generally through class discussions and formally through a review of worksheets and K-W-L charts.

• Collect Venn diagrams and the Cell Factory Worksheet for individual assessment.

• Collect and check the Cell Concepts worksheet in order to assess whether students understand the concepts from Lessons 1 and 2.

Day 1

Start the lesson by briefly reviewing where the previous lesson left off: “Yesterday we learned that cells are the basic building blocks of all living organisms. Today we are going to learn about how cell parts perform all the functions of living things. They work together with other similar cells to help us move, eat, think, and so on.”

Display the Prokaryotic and Eukaryotic Cells Poster for the class to see (S-6-4-2_Prokaryotic and Eukaryotic Cells Poster.doc). Make copies for each student if an overhead projector is unobtainable.

“What are the differences between the two cells?” Give students a moment to examine the poster and come up with the answers. Possible answers may include:

1. Presence of flagella
2. Number of parts/components
3. Complexity
4. Presence of a nucleus

Explain that the number of internal structures and the nucleus being essential differences between the two types of cells. “The two cells represent prokaryotic and eukaryotic organisms. Can anyone tell me why having a nucleus is important?” Students may be unfamiliar with the terms but give them some time to brainstorm. Review their comments as a class before moving on to note-taking.

Tell students, “Most organisms are prokaryotes and they have just one cell. They are able to carry out all life functions even though they only have one cell. How do you think they survive? (Hint: Look at the cell parts).” Answers will vary, but should relate prokaryote cell parts with life functions.

“A nucleus is the control center or “brain” of each cell. It allows a cell to perform more functions, and organisms that have these types of cells are able to do more things. We have a nucleus in each of our cells, so we have eukaryotic cells in our bodies. Now we are going to learn more about each type of cell and what parts make them work.”

Instruct students to take out their science journals and set up a K-W-L chart with the following information in it.

Give students time to create their K-W-L charts and fill in the information above. Next, have students pair up with one other student to brainstorm answers to questions 1 through 4 in the W section of their K-W-L charts. When finished, collect responses from pairs to see which group had the most number of cell similarities correct. Assign appropriate rewards reflective of classroom procedures. Provide students with clues to obtain the remaining similarities by asking them the following, leading questions:

5. “Can anything enter or leave a cell?”
6. “How does a cell keep what it wants and get rid of what it doesn’t?”
7. “When more cells are made, how do cells know what job or function to perform?”
8. “What gives cells their shape?”

Give students a few minutes to discuss their answers in pairs and modify their similarities reflectively. Collect students’ responses again, but lead students toward all similarities through Socratic dialogue/leading questions, for example: “All cells have specific functions. DNA is responsible for a cell’s characteristics like shape, size, color, and function. If all cells perform specific functions, do they all have DNA?”

Once all responses have been given or students have exhausted their attempt to answer questions 1-4, review the answers and have students correct any mistakes.

Instruct students to put their K-W-L charts away for the next activity, but inform them that questions 3–5 will be addressed after the next activity on cell organelles. Hand out the Cell and Factory Worksheet (S-6-4-2_Cell and Factory Worksheet and KEY.doc) to each student. Provide students with the following directions:

9. “Read through the worksheet first to get acquainted with each organelle and its function in the cell.”
10. “Next, read through the second page, which lists common factory jobs and their descriptions.”
11. “Finally, match the factory job from the second page with the cell organelle with the most similar job function.”

When students are finished, allow them to work with a partner to review their answers and come up with any questions on the material. Review the answers with students (the key is provided with the worksheet) and address any student questions.

Day 2

Display the Plant and Animal Cells Poster for the class (S-6-4-2_Plant and Animal Cells Poster.doc). Ask students to identify similarities between the two cells by raising their hands and providing comments. Examples of similarities and differences are listed below. Do not provide students with more examples than they provide, as you will fill in the K-W-L chart later on.

Similarities:

12. Similar organelles (mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles)
13. DNA
14. Cytoplasm

Differences:

15. Plants have a cell wall
16. Plants have chloroplasts
17. Plants have larger vacuoles

Then, show students the “What Cells Look Like Under a Microscope” table on the second page of the Plant and Animal Cells Poster. Have them answer the questions in the table. Also, ask “How can drawings of plant and animal cells help us to better understand cells when we look at them under a microscope?”

Instruct students to take out their K-W-L charts and answer question 5. Use the notes below as an answer key.

When students are finished filling out their K-W-L charts, hand out copies of the Plant and Animal Cell Venn Diagram (S-6-4-2_Plant and Animal Cell Venn Diagram and KEY.doc), and instruct students to read the directions and begin working. This assignment may be used for homework if time is an issue.

Hand out copies of the Cell Concepts worksheet and have students complete it individually (S-6-4-2_Cell Concepts and KEY.docx). This worksheet includes concepts from Lessons 1 and 2.

Extension:

• Students who need more practice with the standards can complete partially-filled out K-W-L charts, which are modified to individual needs. Students may also provide answers to worksheets and diagrams orally.

• For the Cell and Factory worksheet, it may be helpful to allow students to cut and paste the factory jobs next to the appropriate organelle functions. Students may read more about how the cell organelles function together as a system at the Web site, “A Busy Factory” (see Related Resources).

18. Students going beyond the standards can complete a second cell function comparison activity in which they compare cell functions of the following organelles to basic anatomical functions in the human body. Students will create a table with the following organelles, including organelle functions and the human body parts/functions that they think best match the organelle functions.

Example:

Organelle	Function	Human Body Part	Function
Nucleus	Control center of the cell	Brain	Control center of the body

27. Organelles to use include:

Cell membrane

Nucleus

Endoplasmic reticulum

Ribosomes

Golgi apparatus

Lysosomes

Mitochondria

Cytoplasm

Vacuole