Materials

Standards

Objectives

  • Identify the basic structure of cells

  • Identify similarities and differences in plant and animal cells

  • Understand how cells work

Key Concept

  • Cells are the basic units of structure and function in living things

Vocabulary

Tier 2 Function
Tier 3 Cell
Diffusion
Nucleus

Evidence-Based Reading

  • Set a Purpose for Reading: Before students read the lesson, have them make a KWL chart to determine what they know and what they want to know. Later, they can fill in the column about what they learned. Tell students they can also preview the lesson headings and subheadings to get an idea of what topics will be covered. Skim the text to find out how the author presents the material and get an idea of what kinds of diagrams and charts are provided.

21st Century Skill

  • Critical Thinking and Problem Solving: Have students work in pairs to practice writing explanations. Have students take turns interviewing each other and writing a profile based on the information provided. Interviewers could begin with general questions to find a specific topic of interest. Interviewees may provide information about a hobby or a favorite place to visit. Have students write clear, orderly explanations of the partner’s information. Explanations should be factual only and free of opinion.

Interactive Strategy

  • Create and Label Drawings

Writing Topic

  • Review the definition of a summary and write the definition on the board. Then have partners exchange the summaries they wrote about diffusion. Encourage students to offer their partners suggestions on how to make their summaries more effective.

Writing Practice

  • Determine Conclusions

  • Use Reasoning, Planning, and Evidence

Before Lesson

At some point, most students have probably studied cells but may not know or remember much detail. Have a discussion with students about what they already know about plant and animal cells and what they’d like to learn. Write their answers on the board or on a large sheet of paper. Have students check off each item on the list as they work through the lesson.

Background

Each member of a team-whether a sports team, an acting troupe, or a community action committee-plays a specific role within the team and follows a unique set of rules for that role. At the same time, each member contributes to the overall function of the team. Ask students to visualize this concept as they learn about cells.

Guided Practice

  • The Structure of Cells
    • Cytoplasm
    • Cell Structures
      • Cell Membrane
      • Nucleus
    • Specialized Cell Structures
    • Specialized Cell Structures in Plants
    • How a Cell Works
    • Diffusion
    • Active Transport

Core Skill

Determine Conclusions: After students have read the text, have students work together in pairs. Have one student write a conclusion that answers the question Why does a cell have specialized parts? Ask the other student to point out the sentences in the text that serve as evidence supporting this conclusion.

Support Conclusions: Tell students that most of the time, in science writing, conclusions will be easy to determine and there will be plenty of supporting material included. This is because the practice of science requires that evidence be provided for hypotheses and other scientific statements. Ask students what might happen if scientists did not provide information that supports their conclusions when they share their findings with other scientists.

Extension

Create and Label Drawings: Have students draw and label the plant cell and the animal cell shown on page 136. Then ask students to prepare a three-column table. Have students’ list plant cell structures in the first column and animal cell structures in the second column. Remind students that many of these structures are found in both plant and animal cells. In the third column, ask students to use their own words to state the function of each structure.

Use Reasoning, Planning, and Evidence: Challenge students to research the use of intravenous saline solution to treat dehydration. Ask students to cite evidence supporting the use of IV saline solutions and challenge them to draw conclusions about why an intravenous saline solution is used instead of water.

Lesson Review