The Cell Theory: An Evidence-Based Argument

Learning Resource Type

Lesson Plan

Subject Area

Science

Grade(s)

7

Overview

This lesson will require students to research the three tenets of cell theory and describe the scientific evidence that supports this theory. After students complete their research, they will engage in all steps of the writing process, including prewriting, outlining, revising, and editing. At the conclusion of the lesson, students will create a three-paragraph argumentative essay to examine the cell theory and the scientific evidence that supports this theory.

This lesson results from a collaboration between the Alabama State Department of Education and ASTA.

Science (2015) Grade(s): 7

SC15.7.1

Engage in argument from evidence to support claims of the cell theory.

UP:SC15.7.1

Vocabulary

  • Cell
  • Cell theory
  • Unicellular
  • Multicellular
  • Living
  • Non-living
  • Organism
  • Evidence
  • Scientific argument
  • Claims

Knowledge

Students know:
  • The presence or absence of cells in living and nonliving things.
  • The presence of cells in a variety of organisms, including unicellular and multicellular organisms.
  • Different types of cells within one multicellular organism.
  • Cells only arise from preexisting cells by division.
  • The cell is the structural and functional unit of all living things.

Skills

Students are able to:
  • Make a claim about a given explanation or model for a phenomenon, including the cell theory .
  • Identify and describe the given evidence that supports the claim.
  • Evaluate the evidence and identify its strengths and weaknesses.
  • Use reasoning to connect the necessary and sufficient evidence and construct the argument.
  • Present oral or written arguments to support or refute the given explanation or model for the phenomenon.

Understanding

Students understand that:
  • The three components of the cell theory:
  • All life forms are made from one or more cells.
  • Cells only arise from pre-existing cells.
  • The cell is the smallest unit of life.

Scientific and Engineering Practices

Engaging in Argument from Evidence

Crosscutting Concepts

Structure and Function

Primary Learning Objectives

  • Students will research the cell theory and the scientific evidence that supports this theory.

  • Students will analyze and evaluate the past and current scientific research that supports the cell theory.

  • Students will compose an argumentative essay that details the evidence that supports the cell theory.

Additional Learning Objective(s)

Students will engage in the writing process, including the steps of prewriting, outlining, revising, editing, and final publication.

Procedures/Activities

Before Strategy/Engage: 15 minutes

1. Give students two to three minutes to brainstorm a list of characteristics that all living things have in common.  NOTE: An online mind mapping tool such as MindMeister may be used for this step.  

2. Ask for student volunteers to share one idea from their brainstorm and create a class list on the board.

3. Allow students to move into groups of two to four students. Tell students their group should attempt to narrow down the class list created in step one to just three items. Allow students to discuss this task with their group members for about five minutes.

4. After students complete their discussion, tell students that scientists have narrowed down the list to just three items, and this list is called the cell theory. According to this theory, these three characteristics apply to all living things.

  • All living things are made of cells.
  • Cells are the basic units of structure and function of living things.
  • Living cells come from other living cells.

During Strategy/Explore & Explain: 60+ minutes

1. The teacher should give each student a copy of the Cell Theory Research Graphic Organizer (see attachments). 

2. The teacher should show the following video clip. Students should add notes to their graphic organizer while viewing the video clip. Students will listen for the names of the three scientists who are credited with developing this theory and write their names in the top box of the graphic organizer. The students should also record the discoveries that support each tenet of the cell theory in the boxes at the bottom of the graphic organizer. 

"The Wacky History of Cell Theory" from TED-Ed on youtube.com (6:11)

3. Students will need access to the articles listed in the materials section. Students may use a printed copy of the article or access the article online using an Internet-capable device.

 

 

4. Students will read the articles while continuing to add information to the Cell Theory Research Graphic Organizer (see attachments). This graphic organizer will require students to research the scientific evidence and discoveries that support the claims of the cell theory.

Note: Depending on students’ abilities, the teacher may wish to read the articles and complete the graphic organizer as a whole class, or model this skill one time before allowing students to read the articles independently or with a partner or small group. In addition, the teacher may wish to require students to cite the articles used during the lesson in MLA or APA format to include in a bibliography page for students' final essay.

After Strategy-Explain & Elaborate-60+ minutes

1. After reading the articles and completing research notes using the graphic organizer, students will begin to develop their argumentative three-paragraph essay. The teacher may wish to present the students with the grading rubric before they begin writing: Persuasion Rubric from readwritethink.org. The teacher should decide in advance if he or she will allow students to present their personal opinion of the cell theory or require a strictly scientifically-based argumentative essay. The rubric does require students to state a personal opinion. The teacher could remove this from the rubric if needed.

Note: Depending on students’ experiences in writing in an argumentative format, the teacher may wish to provide more or less scaffolding during this portion of the lesson.

2. Students will begin the writing process by planning in their essay using the Persuasion Map Graphic Organizer from readwritethink.org. Alternatively, the students may complete this persuasion map in an online format using this website: Persuasion Map Student Interactive from readwritethink.org.

Note: This graphic organizer was developed for a five paragraph essay. To modify it for a three paragraph essay, the teacher or students can cross off the "b" and "c" boxes for "Facts or Examples". With this modification, students will be required to explain one discovery that supports the cell theory. The "thesis" should contain a statement about the cell theory and list the three main tenets of the cell theory. The "main reasons" and "facts or examples" should be the discoveries that scientists have made to support the claims of the cell theory that students learn during their research. The "conclusion" should summarize the most important details of the student's argument.

3. After completing the Persuasion Map, students should begin writing their essay. The teacher may require students to hand write or type their rough draft.

4. After completing the rough draft, students should review their own writing using the Evidence-Based Argument Checklist from readwritethink.org. Students should also switch papers with a partner to allow a classmate to complete the same checklist. (The teacher may wish to make a two-sided copy of the Evidence-Based Argument Checklist, so students can use one side for a self-check and one side for a peer-check.) As students review their essay and their peer's essay, they should also be editing spelling and grammatical mistakes.

5. After each student has revised and edited their own essay and had at least one peer revise and edit their essay, the student should complete a final draft of their essay that details the evidence that supports the cell theory. The teacher could require this to be handwritten or typed.


Before Strategy/Engage: 15 minutes

1. Give students two to three minutes to brainstorm a list of characteristics that all living things have in common.  NOTE: An online mind mapping tool such as MindMeister may be used for this step.  

2. Ask for student volunteers to share one idea from their brainstorm and create a class list on the board.

3. Allow students to move into groups of two to four students. Tell students their group should attempt to narrow down the class list created in step one to just three items. Allow students to discuss this task with their group members for about five minutes.

4. After students complete their discussion, tell students that scientists have narrowed down the list to just three items, and this list is called the cell theory. According to this theory, these three characteristics apply to all living things.

  • All living things are made of cells.
  • Cells are the basic units of structure and function of living things.
  • Living cells come from other living cells.

During Strategy/Explore & Explain: 60+ minutes

1. The teacher should give each student a copy of the Cell Theory Research Graphic Organizer (see attachments). 

2. The teacher should show the following video clip. Students should add notes to their graphic organizer while viewing the video clip. Students will listen for the names of the three scientists who are credited with developing this theory and write their names in the top box of the graphic organizer. The students should also record the discoveries that support each tenet of the cell theory in the boxes at the bottom of the graphic organizer. 

"The Wacky History of Cell Theory" from TED-Ed on youtube.com (6:11)

3. Students will need access to the articles listed in the materials section. Students may use a printed copy of the article or access the article online using an Internet-capable device.

 

 

4. Students will read the articles while continuing to add information to the Cell Theory Research Graphic Organizer (see attachments). This graphic organizer will require students to research the scientific evidence and discoveries that support the claims of the cell theory.

Note: Depending on students’ abilities, the teacher may wish to read the articles and complete the graphic organizer as a whole class, or model this skill one time before allowing students to read the articles independently or with a partner or small group. In addition, the teacher may wish to require students to cite the articles used during the lesson in MLA or APA format to include in a bibliography page for students' final essay.

After Strategy-Explain & Elaborate-60+ minutes

1. After reading the articles and completing research notes using the graphic organizer, students will begin to develop their argumentative three-paragraph essay. The teacher may wish to present the students with the grading rubric before they begin writing: Persuasion Rubric from readwritethink.org. The teacher should decide in advance if he or she will allow students to present their personal opinion of the cell theory or require a strictly scientifically-based argumentative essay. The rubric does require students to state a personal opinion. The teacher could remove this from the rubric if needed.

Note: Depending on students’ experiences in writing in an argumentative format, the teacher may wish to provide more or less scaffolding during this portion of the lesson.

2. Students will begin the writing process by planning in their essay using the Persuasion Map Graphic Organizer from readwritethink.org. Alternatively, the students may complete this persuasion map in an online format using this website: Persuasion Map Student Interactive from readwritethink.org.

Note: This graphic organizer was developed for a five paragraph essay. To modify it for a three paragraph essay, the teacher or students can cross off the "b" and "c" boxes for "Facts or Examples". With this modification, students will be required to explain one discovery that supports the cell theory. The "thesis" should contain a statement about the cell theory and list the three main tenets of the cell theory. The "main reasons" and "facts or examples" should be the discoveries that scientists have made to support the claims of the cell theory that students learn during their research. The "conclusion" should summarize the most important details of the student's argument.

3. After completing the Persuasion Map, students should begin writing their essay. The teacher may require students to hand write or type their rough draft.

4. After completing the rough draft, students should review their own writing using the Evidence-Based Argument Checklist from readwritethink.org. Students should also switch papers with a partner to allow a classmate to complete the same checklist. (The teacher may wish to make a two-sided copy of the Evidence-Based Argument Checklist, so students can use one side for a self-check and one side for a peer-check.) As students review their essay and their peer's essay, they should also be editing spelling and grammatical mistakes.

5. After each student has revised and edited their own essay and had at least one peer revise and edit their essay, the student should complete a final draft of their essay that details the evidence that supports the cell theory. The teacher could require this to be handwritten or typed.

Assessment Strategies

Formative Assessment

The students will be informally assessed during the class discussion during the before strategy. The teacher should assess students' research by reviewing their Cell Theory Research Graphic Organizer. The teacher should informally assess students' rough draft writing by reviewing the Evidence-Based Argument Checklist.

Summative Assessment

The students will be formally assessed on their final draft of their argumentative essay using the Persuasion Rubric from readwritethink.org.

Acceleration

If students require acceleration strategies, the teacher could increase the length requirement of the final essay from a three paragraph essay to a five paragraph essay.

Students who meet the primary learning objectives could extend their learning by creating a rap or song about cell theory.

Intervention

The teacher may wish to provide additional scaffolding to those students requiring extra assistance during the after strategy of the lesson. The teacher could also pair struggling students with a peer.

The teacher may reduce the length requirement for the essay (for example, from three paragraphs to one paragraph focusing on the evidence that supports the claims for the cell theory). The teacher may also provide additional time for the writing process for those students who require it.

Total Duration

Greater than 120 Minutes

Background/Preparation

Students need not be familiar with the cell theory, as this lesson will introduce students to this scientific concept. Students should have experience in developing argumentative writing pieces. If students have not had experience in this area, the teacher may wish to introduce this skill prior to teaching this lesson. The following website introduces strategies to teach this writing skill: Developing Persuasive Writing Strategies from readwritethink.org

The teacher should be familiar with the three tenets of cell theory and the scientific discoveries that support this theory. The development of this theory, which is the foundation of biology, began in the 17th century with the invention of the microscope and exists as a large body of scientific research today. The development of the cell theory has been attributed to Schleiden, Schwan, and Virchow. The cell theory states:

1) All living things are made of cells.

2) Cells are the basic units of structure and function of living things.

3) Living cells come from other living cells.

To prepare for the lesson, the teacher should make copies of all required handouts and informational texts. 

Materials and Resources

Student Materials (per student)

Pencil

Notebook paper

Copies of the informational text (or Internet-capable devices to view informational text)

Cell Theory Research Graphic Organizer (see attachments)

Persuasion Map Graphic Organizer from readwritethink.org (an online version is also available)

Note: This graphic organizer was developed for a five paragraph essay. To modify it for a three paragraph essay, the teacher or students can cross off the "b" and "c" boxes for "Facts or Examples".

Website Links Used in Lesson (to be copied prior to lesson if Internet-capable devices are unavailable to students)

"Discovery of Cells and the Development of Cell Theory" from smithlifescience.com

"Cell Theory" from saylor.org

"Cell Theory" from the University of Miami Department of Biology

Handouts Used During Lesson (to be copied prior to lesson)

Persuasion Rubric from readwritethink.org to be used for summative assessment

Evidence-Based Argument Checklist from readwritethink.org

Technology Resources Needed

Student Technology Resources

An Internet-capable device to view informational text (if available)

Online prewriting graphic organizer: Persuasion Map Student Interactive from readwritethink.org (a PDF file is also available)

Website Links Used in Lesson

"Discovery of Cells and the Development of Cell Theory" from smithlifescience.com

"Cell Theory" from saylor.org

"Cell Theory" from the University of Miami Department of Biology

Teacher Technology Resources

Teacher computer with Internet access

Interactive whiteboard and/or projector with ability to project sound

Video clip from YouTube for during strategy: "The Wacky History of Cell Theory" from TED-Ed on youtube.com (6:11)

Approved Date

2016-12-28
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