High School Biology Textbooks: A Benchmarks-Based Evaluation

Biology: The Dynamics of Life. Glencoe/McGraw-Hill, 2000

Cell Structure and Function: Instructional Analysis

I: Providing a Sense of Purpose
Conveying unit purpose Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. A problem, question, representation (or otherwise identified purpose) is presented to students.
  2. The problem, question, representation (or otherwise identified purpose) is likely to be comprehensible to students.
  3. The problem, question, representation (or otherwise identified purpose) is likely to be interesting and/or motivating to students.
  4. Students are given an opportunity to think about and discuss the problem, question, representation (or otherwise identified purpose).
  5. Most lessons are consistent with the stated purpose and those that are not are explicitly labeled as digressions.
  6. The material returns to the stated purpose at the end of the unit.

Rating = Poor
The material meets indicator 1 and minimally meets indicator 5, but does not meet indicators 2–4 and 6.

Indicator 1: Met
The material provides purposes for individual chapters but not for units. Chapters provide explicit statements of purpose. At the beginning of each chapter, the student text includes brief sections titled “What You’ll Learn” and “Why It’s Important.” For example, Chapter 7: A View of the Cell begins with the following statements:

What You’ll Learn

  • You will distinguish eukaryotic and prokaryotic cells.
  • You will learn the structure and function of the plasma membrane.
  • You will relate the structure of cell parts to their functions.

Why It’s Important

A knowledge of cell structure and function is essential to a basic understanding of life.

p. 174s

Unit introductions do not begin with a question or problem that students will be trying to solve in the unit. Instead, unit introductions present a topic related to the upcoming chapters. For example, at the beginning of Unit 3: The Life of a Cell, teachers are instructed to have students focus on a photograph:

Ask students to describe some of the things they see in the photograph of cells of the retina in terms of color, shape, and other visual characteristics. We appreciate the amazing variety and details of the visual world around us through the work of specialized cells in the retina. Each retinal cell receives a small piece of an image from another cell, such as the pyramidal neuron from another part of the brain, and only by working together can cells piece together all of the information to give an accurate view of the world around us.

p. 142t

Even though this introduction does not provide a purpose for the unit, students might surmise a purpose from the title of the unit “The Life of a Cell.”

Indicator 2: Not met
Purpose statements for chapters and units are not likely to be comprehensible to students. Unit purpose seems only slightly related to the following chapters, while the chapter purposes include technical terms (such as “eukaryotic,” “prokaryotic,” and “plasma membrane”) that are not likely to be familiar to students.

Indicator 3: Not met
Neither unit nor chapter purposes are likely to be interesting or motivating to students. No problem or question is provided that could spark interest.

Indicator 4: Not met
Students are not asked to think about the purpose statements. Each chapter begins with a Getting Started Demo feature in the teacher notes which is described as providing “an inquiry approach to starting the chapter” (p. 17T). While the Getting Started Demos could provide opportunities for students to think about the purpose statements, the Getting Started Demos for the chapters addressing the key ideas were not related to the purpose of each chapter.

Indicator 5: Minimally met
Readings within the chapters reflect the bulleted list of objectives under the What You’ll Learn headings. However, some reading sections and activities are not clearly linked to these bulleted statements. For example, Section 7.1 The Discovery of Cells, focuses on the history of the cell theory and the development of microscopes (pp. 175–180s). While these topics are related to the general topic of cells, they are not related to the bulleted statements at the beginning of the chapter. Similarly, the Bellringer activity on surface area (p. 185t) is not related clearly to the bulleted statements of purpose at the beginning of the chapter.

Indicator 6: Not met
While each chapter provides a summary of the main ideas and vocabulary of the text sections (e.g., p. 197s), these summaries are not linked to the purpose statements at the beginning of the chapter.

Conveying lesson/activity purpose Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material conveys or prompts teachers to convey the purpose of the activity to students.
  2. The purpose is expressed in a way that is likely to be comprehensible to students.
  3. The material encourages each student to think about the purpose of the activity.
  4. The material conveys or prompts teachers to convey to students how the activity relates to the unit purpose.
  5. The material engages students in thinking about what they have learned so far and what they need to learn/do next at appropriate points.

Rating = Poor
The material meets indicator 1 and somewhat meets indicator 3, but does not meet indicators 2, 4, and 5.

Indicator 1: Met
Three features can help to convey the purpose of readings for students:

When you work on a group project, each person has his or her own skills and talents that add a particular value to the group’s work. In the same way, each component of a eukaryotic cell has a specific job, and all of the parts of the cell work together to help the cell survive.

p. 185s

Each section starts with an introductory paragraph to help convey the purpose of the reading to students (e.g., pp. 175s, 181s).

Indicator 2: Not met
Both section titles and objectives include technical vocabulary—such as “eukaryotic,” “highly folded membranes,” and “fluid mosaic model” (pp. 185s, 181s)—that may not be comprehensible to students who have not already studied the topic.

Indicator 3: Somewhat met
Students are given some opportunities to think about section titles, objectives, and introductions with the Bellringer activity in the teacher notes at the start of each section. For example, at the start of the section The Plasma Membrane (p. 181st), teachers are asked to display a transparency showing a test tube with two types of molecules in it, but covered with a membrane and inverted in a beaker of water, the sugar molecules appear both inside and outside the test tube, while the starch molecules are only in the test tube. The two questions at the bottom of the transparency to be asked of students are: “What is happening to the starch and the sugar?” and “What does this tell you about the membrane covering the test tube?” (p. 181t). However, other Bellringer activities are less obviously related to the chapter sections (e.g., p. 185t).

Indicator 4: Not met
The material does not convey or prompt the teacher to convey how the material is tied to the chapter or unit purpose.

Indicator 5: Not met
The material does not engage students at appropriate points in thinking about what they have learned so far and what they need to learn next.

Justifying lesson/activity sequence Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material includes a logical or strategic sequence of activities.
  2. The material conveys the rationale for this sequence.

Rating = Fair
The material somewhat meets indicator 1, but does not meet indicator 2.

Indicator 1: Somewhat met
The topics covering the key ideas about cell structure and function appear to be logically sequenced, but the presentation of ideas within each topic does not. The topic sequence for Chapter 7: A View of the Cell includes: cell theory, general information about the two basic types of cells and microscopes, the plasma membrane, and lastly, more specific information about cellular organelles. However, the presentation of key ideas within each topic is interrupted by more sophisticated and/or tangential information. For example, the section on the organelles of the cell focuses mostly on the names and details of the structures of the organelles (e.g., “It is within these thylakoid membranes that the energy from sunlight is trapped. These inner membranes are arranged in stacks of membranous sacs called grana, which resemble stacks of coins. The fluid that surrounds the grana membranes is called stroma” [p. 190s]), without relating the structural details to the functions they serve.

Indicator 2: Not met
The material does not convey a rationale for the sequence of units or chapters or for the sequence of readings or other activities within chapters.

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II: Taking Account of Student Ideas
Attending to prerequisite knowledge and skills Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material alerts the teacher to specific prerequisite ideas or skills (versus stating only prerequisite topics or terms).
  2. The material alerts teachers to the specific ideas for which the prerequisites are needed.
  3. The material alerts students to prerequisite ideas or experiences that are being assumed.
  4. The material adequately addresses (provides instructional support for) prerequisites in the same unit or in earlier units (in the same or other grades). (The material should not be held accountable for addressing prerequisites from an earlier grade range. However, if a material does address such prerequisites they should count as evidence for this indicator.)
  5. The material makes adequate connections (provides instructional support for connections) between ideas treated in a particular unit and their prerequisites (even if the prerequisites are addressed elsewhere).

Rating = Poor
The material minimally meets indicator 4, but does not meet indicators 1–3 and 5.

Indicator 1: Not met
The material does not alert the teacher to specific prerequisite ideas or skills.

Indicator 2: Not met
The material does not alert teachers to the specific ideas for which prerequisites are needed.

Indicator 3: Not met
The material does not alert students to prerequisite ideas or experiences that are being assumed.

Indicator 4: Minimally met
The material does not adequately address prerequisites in the same unit or in earlier units. Only three of the five prerequisite ideas for cell structure and function are mentioned briefly in the student text. For example, part of the prerequisite idea that cells carry out many of the same basic functions of organisms, such as extracting energy and getting rid of waste [5C(6-8)/3] is mentioned once in a figure caption in the first chapter. The caption explains that “Like all organisms, earthworms are made up of cells. The cells form structures that carry out essential functions, such as feeding or digestion. The interaction of these structures and their functions result in a single, orderly, living organism” (p. 7s). Similarly, part of the prerequisite idea that “Atoms may stick together in well-defined molecules….” [4D(6-8)/1] is mentioned once in the student text. The text states that “A molecule is a group of atoms held together by covalent bonds and having no overall charge” (p. 150s). The following text does not further explain this prerequisite, rather it continues by explaining how formulas for molecules are written and how ionic bonds form. Lastly, the prerequisite idea that “The rate of reactions among atoms and molecules depends on how often they encounter one another, which is affected by the concentrations, pressure, and temperature of the reacting materials” [4D(9-12)/9] is treated partially in the student text in the statement:

Chemical reactions can occur only when conditions are right. For example, a reaction might depend on temperature, the availability of energy, or a certain concentration of a substance dissolved in solution. Chemical reactions in organisms also depend on the pH of the environment.

p. 154s

In addition, a laboratory activity has students look at how temperature affects the behavior of an enzyme (pp. 168–169st).

Indicator 5: Not met
The material does not make connections between key ideas treated in a unit and their prerequisite ideas. While the text states a prerequisite idea about molecules [4D(6-8)/1] in its presentation of compounds and bonding (pp. 149–151s), it does not connect it to the key idea that “The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins” (Idea c). Such a connection would explain how the function of a molecule depends on the structure of that molecule. Similarly, even though the text explains that reaction rates depend on factors such as concentration, temperature, and pH and provides a laboratory activity about an enzyme’s behavior in different temperatures, this material is not related to the key idea that cells function best within a narrow range of temperature and acidity (Idea d).

Alerting teachers to commonly held student ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material accurately presents specific commonly held ideas that are relevant to the key ideas and have appeared in scholarly publications (rather than just stating that students have difficulties with particular ideas or topics).
  2. The material clarifies/explains commonly held ideas (rather than just listing them).

Rating = Not rated
For the topic of cell structure and function, materials were not rated on this criterion because no research base outlines commonly held student ideas.

Assisting teachers in identifying their students’ ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material includes specific questions or tasks that could be used by teachers to identify students’ ideas.
  2. The questions/tasks are likely to be comprehensible to students who have not studied the topic and are not familiar with the scientific vocabulary.
  3. The questions/tasks are identified as serving the purpose of identifying students’ ideas.
  4. The material includes questions/tasks that ask students to make predictions and/or give explanations of phenomena (rather than focus primarily on identifying students’ meanings for terms).
  5. The material suggests how teachers can probe beneath students’ initial responses to questions or interpret student responses (e.g., by providing annotated samples of student work).

Rating = Poor
The material does not meet any indicators.

Indicator 1: Not met
The material provides no questions that could be used by the teacher to find out what students know about the key ideas before instruction begins. Although the material provides teachers with a Bellringer activity to introduce each section (e.g., pp. 175t, 181t, 185t), the questions accompanying the activity are not likely to reveal students’ ideas about the key ideas. Two of these Bellringer activities are not related to the key ideas: one focuses on microscopes (p. 175t) and the other on surface area (p. 185t). The third Bellringer activity relates to the control of the cell membrane (p. 181t), but the questions provided are not likely to elicit students’ ideas on the cell membrane. The teacher is to display a transparency showing a test tube with two types of molecules in it (sugar and starch), but covered with a membrane and inverted in a beaker of water. The sugar molecules appear both inside and outside the test tube, while the starch molecules are only in the test tube. Two questions at the bottom of the transparency ask students: “What is happening to the starch and the sugar?” and “What does this tell you about the membrane covering the test tube?” (p. 181t). Neither question relates this phenomenon to the cell membrane and students are not likely to understand that the test tube is a model of the cell and its membrane. In addition, each chapter begins with a Getting Started Demo feature in the teacher notes which is described as providing “an inquiry approach to starting the chapter” (p. 17T). While the Getting Started Demos could be a source of questions to identify student ideas, the Getting Started Demos in the relevant chapters for cell structure and function were not related to the key ideas.

Indicator 2: Not met
There are no questions to be examined for comprehensibility.

Indicator 3: Not met
The questions are not identified as serving the purpose of identifying students’ ideas.

Indicator 4: Not met
None of these questions asks students to give explanations or make predictions.

Indicator 5: Not met
The material offers no suggestions for how teachers can probe beneath students’ initial responses to questions. For example, the teacher’s guide does not tell the teacher to listen for his/her students’ responses or to avoid correcting their ideas at a given time. Without these warnings, it is unlikely that the questions provided will be used to elicit student ideas.

Addressing commonly held ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material explicitly addresses commonly held ideas.
  2. The material includes questions, tasks, or activities that are likely to help students progress from their initial ideas, for example, by
    1. explicitly challenging students’ ideas, for example, by comparing their predictions about a phenomenon to what actually happens
    2. prompting students to contrast commonly held ideas with the scientifically correct ideas, and resolve differences between them
    3. extending correct commonly held ideas that have limited scope.
  3. The material includes suggestions to teachers about how to take into account their own students’ ideas.

Rating = Not rated
For the topic of cell structure and function, materials were not rated on this criterion because no research base outlines commonly held student ideas.

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III: Engaging Students with Relevant Phenomena
Providing variety of phenomena Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Phenomena could be used to support the key ideas.
  2. Phenomena are explicitly linked to the relevant key ideas.

Rating = Poor
Since the rating scheme depends on how many phenomena meet both of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

The material provides no phenomena to support the key ideas. While the material provides a few phenomena related to these key ideas, none was shown to be explained by the key ideas. Hence, the phenomena are not likely to help make the ideas credible to students. For example, for the idea that “Every cell is covered by a membrane that controls what can enter and leave the cell” (Idea a), students examine a diagram from an experiment on yeast cell membranes (p. 182s). Living yeast and boiled yeast cells were treated with a stain. Students are to conclude that boiling the yeast cells kills the cells and destroys the membrane’s selective permeability therefore allowing the stain to enter the cell, while the living yeast cells, with their membrane intact, were not stained. However, since the boiled yeast cells have a destroyed membrane, this does not show that the membrane can control what can enter and exit the cell, rather it shows that without a membrane, cells can be stained.

For the idea that cells have specialized parts for specialized functions (Idea b), students read that as a tadpole becomes a frog, lysosomes in a tadpole’s tale begin to digest the unneeded tale (p. 190s). However, this phenomenon is not explained in terms of this key idea. Another possible phenomenon for Idea b presents an experiment in which the nucleus-containing foot of an Acetabularia cell was removed and placed on the stem from a different species of Acetabularia (p. 186st). Students are to conclude that the nucleus (found in the foot region) controls the type of cap that grows back if it is removed. However, the diagram is not adequately explained for students to follow the experiment.

No other relevant phenomena are provided.

Providing vivid experiences Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Each firsthand experience is efficient (when compared to other firsthand experiences) and, if several firsthand experiences target the same idea, the set of firsthand experiences is efficient. (The efficiency of an experience equals the cost of the experience [in time and money] in relation to its value.)
  2. The experiences that are not firsthand (e.g., text, pictures, video) provide students with a vicarious sense of the phenomena. (Please note that if the material provides only firsthand experiences, this indicator is not applicable.)
  3. The set of firsthand and vicarious experiences is sufficient.

Rating = Poor
Since the rating scheme depends on how many phenomena meet all of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

The material meets no indicators. Given that none of the provided phenomena was explained by the key ideas, there is essentially nothing to be judged for vividness.

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IV: Developing and Using Scientific Ideas
Introducing terms meaningfully Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material links technical terms to relevant experiences that develop the idea as the term is used (rather than just having students learn definitions of terms).
  2. The material restricts the use of technical terms to those needed to communicate intelligibly about key ideas.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not link new technical terms to relevant experiences. With few relevant phenomena (see discussion in Category III), there seems to be little point to using the terms other than having students learn their definitions. For example, terms like “organelle” (p. 177s) and “plasma membrane” (p. 181s) are defined in the abstract with no helpful examples given to make the terms concrete for students. Even when the terms are linked to a representation, the representation focuses on the structure of the cell part but does not help to explain the part’s function (e.g., Figure 7.8 on p. 187s and Figure 7.9 on p. 188s).

Indicator 2: Not met
The material does not restrict the use of technical terms to those needed to communicate intelligibly about the key ideas. The key ideas about cell structure and function are introduced along with many unnecessary terms such as “plastids,” “microtubules,” “thylakoid,” “granum,” “stroma,” “nucleolus,” “nuclear pores,” “chromatin,” “transport proteins,” “fluid mosaic model,” “phospholipids,” and “glycerol backbone.”

Representing ideas effectively Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Representation is accurate (or, if not accurate, then students are asked to critique the representation).
  2. Representation is likely to be comprehensible to students.
  3. Representation is explicitly linked to the real thing.

Rating = Poor
Since the rating scheme depends on how many representations meet all of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

Although this material presents several diagrams of cell organelles, such as Figure 7.8 (p. 187s) and Figure 7.9 (p. 188s), none of the diagrams helps to clarify the function of the organelles or how they contribute to the cell as a system. Hence, these diagrams do not focus on the key idea that cells have specialized parts for specific functions (Idea b). For the idea that cells are covered by a membrane that controls what can enter and exit the cell (Idea a), most related diagrams focus on the structure of the membrane rather than the function of control (such as diagrams on pp. 183s, 184s, 204s, and 205s).

However, the text provides a few analogies that could be useful, such as describing the cell membrane as a window screen that lets air in but keeps bugs out (pp. 181–182s). Also, a teacher’s note suggests that teachers ask students to list the body systems that they need to live (p. 188t, Chalkboard Activity). The teacher is to use this list as a way of introducing the organelles that perform the life functions of cells. Two teacher Discussion notes suggest involving students in assessing the strengths and weaknesses of specific analogies, one that compares the cell membrane to the walls of a house (p. 184t) and another that compares the cell to a team (p. 193t). Since most analogies only help to clarify a few features of the reference, asking students to consider the limitations of an analogy is a useful strategy.

The text and teacher’s notes also suggest a few model building activities, but often these focus on structures of the cell rather than functions (e.g., p. 190t). One model building activity has students make a model of a cell membrane using a plastic bag, starch solution, and iodine (p. 204s). Although this could be a good model for the selective permeability of the cell membrane, none of the directions or follow-up questions focuses students on how this simulation models the cell membrane.

Demonstrating use of knowledge Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material consistently carries out (or instructs teachers to carry out) the expected performance (e.g., the student text explains a particular phenomenon using the kinetic molecular theory). (Teacher’s guides often include responses to questions posed in the student text. If the material does not instruct the teacher to use the answers to model the use of knowledge, such responses do not count as instances of modeling.)
  2. The performance is step-by-step.
  3. The performance is explicitly identified as a demonstration of the use of knowledge or skill.
  4. The material provides running commentary that points to particular aspects of the demonstration and/or criteria for judging the quality of a performance.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not demonstrate the use of key ideas or suggest how teachers could do so.

Indicator 2: Not met
No demonstrations are provided.

Indicator 3: Not met
No demonstrations are provided.

Indicator 4: Not met
No demonstrations are provided.

Providing practice Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material provides a sufficient number of tasks in a variety of contexts, including everyday contexts. (In order to determine whether the task/question addresses the actual substance of the key idea, reviewers will need to consider both the question and the expected response in the teacher’s guide.)
  2. The material includes novel tasks.
  3. The material provides a sequence of questions or tasks in which the complexity is progressively increased.
  4. The material provides students first with opportunities for guided practice with feedback and then with practice in which the amount of support is gradually decreased.

Rating = Poor
Since the rating scheme depends on how many practice tasks meet all of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

Two kinds of questions and tasks were considered for this criterion: Chapter Assessment questions at the end of the chapter, and student tasks and questions within the chapter requiring application of ideas presented in the text. The material does not provide a sufficient number of practice questions for the key ideas. While questions are provided for some key ideas, most questions only require students to repeat information found in the text. For example, the following tasks are provided for the idea that cells have specialized parts for specific functions (Idea b):

Which component is NOT stored in plastids?

  1. lipids
  2. pigments
  3. amino acids
  4. starches

p. 198st, question 7

Vacuoles are membrane-bound spaces that serve as temporary storage areas.

p. 198st, question 11

The small bumps shown in this photomicrograph are the site of protein synthesis.

p. 198st, question 12

These questions mainly involve restating information found in the text. Very few questions are provided that ask students to use the key ideas in novel situations, such as the following question:

Making Predictions Predict whether you would expect muscle or fat cells to contain more mitochondria and explain why. Muscle cells are very active cells that use a lot of energy, whereas fat cells are used mainly for storage of fat. Mitochondria are the cell organelles that transform energy for the cell. Therefore, muscle cells will contain more mitochondria.

p. 199st, question 23

For the idea that cells are covered by a membrane that controls what can enter and exit the cell (Idea a), the following questions are provided:

The plasma membrane maintains a chemical balance within a cell by regulating the materials that enter and leave the cell.

p. 198st, question 14

How does the structure of the plasma membrane allow materials to move across it in both directions? Some protein transporters carry materials out of the cell and some carry materials into the cell. The lipid bilayer itself allows diffusion of small molecules in either direction.

p. 199st, question 22

These questions merely involve repeating information found in the text, which sometimes includes more sophisticated language.

For the other key ideas no more than a single question is provided and it is not novel.

The material does not provide a sequence of questions or tasks in which the complexity is progressively increased. Only individual questions are provided.

The material does not provide students first with opportunities for guided practice with feedback and then with practice in which the amount of support is gradually decreased.

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V: Promoting Students’ Thinking about Phenomena, Experiences, and Knowledge
Encouraging students to explain their ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Material routinely encourages students to express their ideas.
  2. Material encourages students not only to express but also to clarify, justify, and represent their ideas (a material is not expected to encourage students to clarify, justify, and represent ideas each time they are asked to express their ideas; however, in the course of teaching a particular key idea the material should provide students with opportunities to clarify, justify, and represent ideas).
  3. Material provides opportunities for each student (rather than just some students) to express ideas.
  4. Material includes specific suggestions on how to help the teacher provide explicit feedback to students or includes text that directly provides students with feedback.
  5. Material includes suggestions on how to diagnose student errors, explanations about how these errors may be corrected, and recommendations for how students’ ideas may be further developed.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not routinely encourage students to express their own ideas about key ideas on cell structure and function. While the material provides several features in the teacher’s guide that could be a source of relevant tasks or questions—for example, Biology Journal, Discussion, Reinforcement, Portfolio, Meeting Individual Needs—few of the tasks or questions focus on the key ideas. Most questions and tasks focus on the structures of organelles, but not the functions:

Use models of plant cells and animal cells (available from biological supply houses) to review and reinforce knowledge of cell parts.

p. 189t

…Have students use paper and other materials to build cell organelles to scale and then hang them inside the classroom cell.

p. 190t

Have students make a large drawing of a mitochondrion or a chloroplast. Drawings should illustrate the internal and external shapes of the organelles.

p. 191t

A few questions or tasks are relevant to the key ideas, such as the following:

Ask students to evaluate the strengths and weaknesses of the analogy that a plasma membrane is similar to the walls of a house.

p. 184t

However, the number of relevant questions is woefully insufficient to give students a chance to express their ideas about the key ideas about cell structure and function.

Indicator 2: Not met
For the few tasks aligned with the key ideas, students are not asked to clarify, justify, or represent their ideas.

Indicator 3: Not met
The material does not provide opportunities for each student to express his/her ideas about cell structure and function.

Indicator 4: Not met
The material does not include specific suggestions to help the teacher provide explicit feedback to students, nor does the text provide feedback.

Indicator 5: Not met
The material does not include suggestions on how to diagnose student errors, explanations about how those errors may be corrected, or recommendations for how students’ ideas may be further developed.

Guiding student interpretation and reasoning Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material includes specific and relevant tasks and/or questions for the experience or reading.
  2. The questions or tasks have helpful characteristics such as
    1. framing important issues
    2. helping students to relate their experiences with phenomena or representations to presented scientific ideas
    3. helping students to make connections between their own ideas and the phenomena or representations observed
    4. helping students to make connections between their own ideas and the presented scientific ideas
    5. anticipating common student misconceptions
    6. focusing on contrasts between student misconceptions and scientific alternatives.
    Please note that while a single high quality task or question sequence might have only one of these characteristics, the set of sightings should exhibit several of them.
  3. There are scaffolded sequences of questions or tasks (as opposed to separate questions or tasks).

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The student text provides Section Assessment questions at the end of each section of text, Analysis and Critical Thinking questions at the end of lab activities, and Discussion Questions and some Reinforcement questions in the teacher notes. However, few of the questions are specific and relevant to the key ideas. For example, the questions provided for the Section Assessment on the cell membrane do not focus on the related key idea (Idea a):

  1. How is the plasma membrane a bilayer structure?
  2. Explain how selective permeability maintains homeostasis within the cell.
  3. What are the components of the phospholipid bilayer, and how are they organized to form the plasma membrane?
  4. Why is the plasma membrane referred to as a fluid mosaic?

p. 184s

And very few of the questions at the end of lab activities focus on the key ideas on cell structure and function, even when the activities could have been related to these ideas. For example, only one question follows the Acetabularia phenomenon (see the description of this phenomenon in the criterion Providing Variety of Phenomena in Category III). Students are asked: “Why is the final cap like that of the cell from which the nucleus was taken? (HINT: Recall the function of the nucleus.)” (p. 186st).

Indicator 2: Not met
None of the questions in the Section Assessments, Discussion Questions, Reinforcements, or at the end of lab activities has helpful characteristics such as framing important issues, helping students make connections between their own ideas and the presented scientific ideas, or anticipating student misconceptions.

Indicator 3: Not met
None of the questions in the Section Assessments, Discussion Questions, Reinforcements, or at the end of lab activities involves scaffolded sequences of questions, which could guide students from phenomena or their own ideas about phenomena to the scientific ideas.

Encouraging students to think about what they have learned Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material gives students an opportunity to revise their initial ideas based on what they have learned (without asking them explicitly to think about how their ideas have changed).
  2. The material engages (or provides specific suggestions for teachers to engage) students in monitoring how their ideas have changed, but does so infrequently in the unit.
  3. The material engages (or provides specific suggestions for teachers to engage) students in monitoring how their ideas have changed and does so periodically in the unit.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not give students an opportunity to revise their initial ideas based on what they have learned.

Indicators 2 and 3: Not met
The material does not engage students in monitoring how their ideas have changed.

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VI: Assessing Progress

To assess students’ understanding of concepts at the end of instruction, Biology: The Dynamics of Life provides a Chapter Assessment guide with individual chapter tests. Chapters 8 and 9 from the 1998 edition of the assessment guide were examined for the first two assessment criteria (the 2000 edition of the assessment guide was unavailable at time of review). According to the Teacher Guide, the student text includes a three-page Chapter Assessment at the end of each chapter that can be used to “determine whether any substantial reteaching is needed” (p. 33T). Hence, relevant items in Chapter Assessments for Chapter 7: A View of the Cell and Chapter 8: Cellular Transport and the Cell Cycle (2000 edition of the student text) were examined for the third assessment criterion, Using Assessment to Inform Instruction.

Aligning assessment to goals Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The specific ideas in the key ideas are necessary in order to respond to the assessment items.
  2. The specific ideas in the key ideas are sufficient to respond to the assessment items (or, if other ideas are needed, they are not more sophisticated than key ideas and have been taught earlier).

Rating = Poor
Since the rating scheme depends on how many assessment tasks meet both of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

Biology: The Dynamics of Life includes very few items in the 1998 test booklet for Chapter 8: A View of the Cell and Chapter 9: Homeostasis and the Plasma Membrane that assess any of the key ideas, which is far from sufficient. Although several questions are provided that focus on the structure of cell organelles, they do not assess the function of the organelles (Idea b). For example:

The folded system of membranes that forms a network of interconnected compartments inside the cell is called the endoplasmic reticulum.

Chapter Assessment, pp. 43 and 294, question 4

In a chloroplast, the stack of membranous sacs are called

  1. stroma.
  2. grana.
  3. plastids.
  4. thylakoid membrane.

Chapter Assessment, pp. 44 and 294, question 3

Other questions also mention the function of organelles, but still focus on the students’ recall of the technical term that is being described in the question. For example:

In plants, the structures that transform light energy into chemical energy are called chloroplasts.

Chapter Assessment, pp. 43 and 294, question 7

In a cell, the sites of protein synthesis are the (ribosomes, nucleolus).

Chapter Assessment, pp. 43 and 294, question 14

One question was provided that focuses on that idea that the cell membrane controls what can enter and exit the cell (Idea a), but it only requires the student to recall the name of the cell structure:

The movement of materials into and out of the cells is controlled by the (cytoplasm, plasma membrane).

Chapter Assessment, pp. 43 and 294, question 12

One question was provided that targets the idea that cells have specialized parts for specific functions (Idea b):

Question: In plants, cells that transport water against the force of gravity are found to contain many more mitochondria than do some other plant cells. What is the reason for this?

Suggested Response: Mitochondria are organelles that produce energy for cell reactions; active cells usually have more mitochondria than do less active cells. It would be reasonable to conclude that the number of mitochondria is in direct relation to the amount of work done by the cells.

Chapter Assessment, pp. 45 and 295, question 3

Some questions are provided that introduce new information, such as:

Question: Many types of animal cells have a thin, flexible cell covering outside the plasma membrane. This cell covering, called a glycocalyx, consists of complex carbohydrates bonded to the proteins and lipids in the plasma membrane. How is the glycocalyx similar to the cell water of a green plant? How is it different?

Suggested Response: Both the glycocalyx and the cell wall surround the plasma membrane. The cell wall is made of cellulose and is fairly thick, stiff, and rigid; the glycocalyx is a complex carbohydrate that is quite thin and flexible. The glycocalyx is bonded to the plasma membrane; the cell wall is not.

Chapter Assessment, pp. 46 and 295, question 1

Lastly, the material provides a few items that focus on the details of experimental design rather than on the key ideas about cell structure and function (see pp. 47 and 296, and 53 and 299, in Chapter Assessment).

No other items are provided to assess the key ideas about cell structure and function.

Testing for understanding Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Assessment items focus on understanding of key ideas.
  2. Assessment items include both familiar and novel tasks.

Rating = Poor
Since few assessment tasks were aligned to the key ideas, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

Of the relevant assessment items described under the previous criterion, only one requires understanding of the key idea. Clearly this is not sufficient to assess students’ understanding of the key ideas examined here.

Using assessment to inform instruction Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material uses embedded assessment as a routine strategy (rather than just including occasional questions).
  2. The material assists teachers in interpreting student responses to diagnose what learning difficulties remain.
  3. The material provides specific suggestions to teachers about how to use the information from the embedded assessments to make instructional decisions about what ideas need to be addressed by further activities.

Rating = Poor
Since the material provides few tasks for this criterion, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

No indicators are met. The material does not use embedded assessment as a routine strategy. Only a handful of relevant questions are included in Chapter Assessments for Chapter 7: A View of the Cell and Chapter 8: Cellular Transport and the Cell Cycle (shown earlier for the criterion Providing Practice in Category IV).

The material does not assist teachers in interpreting student responses to diagnose what learning difficulties remain.

According to the Teacher Guide, the student text includes a three-page Chapter Assessment at the end of each chapter that can be used to “determine whether any substantial reteaching is needed” (p. 33T). However, no specific suggestions are provided on how to use the information from the items to make instructional decisions.

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VII: Enhancing the Science Learning Environment
Providing teacher content support Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Alerts teachers to how ideas have been simplified for students to comprehend and what the more sophisticated versions are (even though students are not required to understand the more sophisticated versions).
  2. Provides sufficiently detailed answers to questions in the student book for teachers to understand and interpret various student responses.
  3. Recommends resources for improving the teacher’s understanding of key ideas.

Rating = Minimal support is provided.
The material provides minimal support in alerting teachers to how ideas have been simplified for students to comprehend and what the more sophisticated versions are. Content background notes usually summarize the student text (e.g., p. 142t, Unit Overview; p. 201t, Key Concepts) or briefly elaborate on one or a few student text concepts (e.g., p. 178t, Background). Overall, the teacher content support is brief, localized, and fragmented.

The material does not usually provide sufficiently detailed answers to questions in the student book for teachers to understand and interpret various student responses. While most answers include expected scientific responses, little, if any, additional information is provided for teachers to field potential student questions or difficulties (e.g., p. 184t, Section Assessment, answer 2; p. 206t, Section Assessment, answer 5). In addition, some questions go unanswered (e.g., p. 200s, Getting Started; p. 201t, Bellringer).

The material provides minimal support in recommending resources for improving the teacher’s understanding of key ideas. The material lists references in introductory notes (p. 50T, Teacher Readings) and in the “National Geographic Teacher’s Corner” section at the beginning of each chapter (e.g., “‘Life Grows Up,’ by Richard Monastersky, April 1998” [p. 174Bt]). While these resources might help teachers improve their understanding of the key ideas, the lists lack annotations about what kind of specific information the resources provide.

Encouraging curiosity and questioning Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Includes suggestions for how to encourage students’ questions and guide their search for answers, respect and value students’ ideas, raise questions of evidence, and avoid dogmatism.
  2. Provides examples of classroom interactions—e.g., dialogue boxes, vignettes, or video clips—that illustrate appropriate ways to respond to student questions or ideas, etc.

Rating = Minimal support is provided.
The material provides a few suggestions for how to encourage students’ questions and guide their search for answers. For example, a teacher note suggests inviting a cell biologist to speak to the class and having the students prepare questions in advance to ask the guest (e.g., p. 213t, TechPrep).

The material provides a few suggestions for how to respect and value students’ ideas. Teacher notes state that multiple student answers should be acceptable for some questions (e.g., p. 182t, Thinking Critically, item 2). Journal activities elicit students’ ideas about particular concepts and issues (e.g., p. 183t, Biology Journal).

The material provides a few suggestions for how to raise questions such as “How do we know? What is the evidence?” and “Are there alternative explanations or other ways of solving the problem that could be better?” However, it does not encourage students to pose such questions themselves. Specifically, the material includes a few tasks that ask students to provide evidence or reasons in their responses (e.g., p. 182st, Thinking Critically, item 3; p. 204st, Analysis, item 2).

The material provides a few suggestions for how to avoid dogmatism. The first chapter portrays the nature of science as a durable yet dynamic human enterprise in which all people can participate (e.g., pp. 11–25s). The material also discusses current biology topics (e.g., pp. 178–179s, Focus On) and issues related to chapter content (p. 170s, BioTechnology). However, the material also contributes to dogmatism by presenting most of the text in a static, authoritative manner with little reference to the work of particular, practicing scientists and expecting single, specific responses for most student tasks.

The material does not provide examples of classroom interactions (e.g., dialogue boxes, vignettes, or video clips) that illustrate appropriate ways to respond to student questions or ideas. However, a limited sense of desirable student-student interactions may be gained from general guidelines (p. 32T, Group Performance Assessment) and particular directions for cooperative group activities (e.g., p. 177t, Portfolio; p. 193t, Reteach).

Supporting all students Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material avoids stereotypes or language that might be offensive to a particular group.
  2. The material illustrates the contribution of women and minorities to science and brings in role models.
  3. The material suggests alternative formats for students to express their ideas during instruction and assessment.
  4. The material includes specific suggestions about how teachers can modify activities for students with special needs.
  5. The material provides strategies to validate students’ relevant personal and social experiences with scientific ideas.

Rating = Some support is provided.
The material generally avoids stereotypes or language that might be offensive to a particular group. For example, photographs include a diverse cultural mix of students and adults (e.g., pp. 176s, 181s, 185s), but the number of photographs that include people throughout the material is few.

The material provides some illustrations of the contributions of women and minorities to science and as role models. Most of the contributions of women and minority scientists, however, appear in separate sections within each chapter entitled Cultural Diversity. Cultural Diversity features include information about particular scientists or cultural groups related to the chapter content. For example, one Cultural Diversity feature suggests discussing the contributions of the African American scientist Ernest Everett Just in the development of understanding about the plasma membrane (p. 182t). The material also includes a related feature entitled Careers in Biology. The Careers in Biology feature briefly describes scientific occupations related to the material, provides information on how students can learn more about the careers, and includes photographs of scientists, who are sometimes women or minorities (e.g., p. 40st). All of these sections highlighting cultural contributions are interesting and informative, but may not be seen by students as central to the material because they are presented in sidebars and teacher notes.

The material suggests multiple formats for students to express their ideas during instruction and assessment, including individual journal writing (e.g., p. 183t, Biology Journal), cooperative group activities (e.g., p. 177t, Portfolio), laboratory investigations (e.g., pp. 194–195s), whole class discussions (e.g., p. 184t, Discussion), essay questions (e.g., p. 183t, Check for Understanding; Chapter Assessment, pp. 45 and 295, question 3), written reports (e.g., p. 196t, Teaching Strategies, item 2), research projects (e.g., p. 176t, Enrichment), visual projects (e.g., p. 176t, Assessment), concept mapping (e.g., p. 199s, Chapter 7 Assessment, item 24), modeling (p. 181t, TechPrep), and portfolio (e.g., p. 183t, Portfolio). However, the material does not usually provide a variety of alternatives for the same task in either instruction or assessment.

The material does not routinely include specific suggestions about how teachers can modify activities for students with special needs. However, the Teacher Wraparound Edition gives general suggestions in introductory notes (pp. 30T–31T) and provides additional activities and resources for students of specific ability levels. At the beginning of each chapter, teacher notes link chapter activities to various learning styles (e.g., p. 174t, Multiple Learning Styles) and provide a key to activity codes for English language learners and different ability levels (e.g., p. 200At, Key to Teaching Strategies). Within each chapter, activities for students with special needs are entitled Meeting Individual Needs (e.g., p. 191t). Other additional activities within chapters include Extension (p. 193t), Reteach (e.g., p. 193t), and Reinforcement (e.g., p. 189t). Supplemental program resources provide further additional activities and resources for students (for a description, see pp. 20T–27T).

The material provides some strategies to validate students’ relevant personal and social experiences with scientific ideas. Some text sections relate specific, personal experiences students may have had to the presented scientific concepts (e.g., p. 181s). In addition, some tasks (e.g., p. 188t, Chalkboard Activity; p. 193st, Section Assessment, item 5) ask students about particular personal experiences they may have had or suggest specific experiences they could have. However, the material rarely encourages students to contribute relevant experiences of their own choice to the science classroom. Overall, support is brief and localized.

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