6th Grade - Unit 3: Cells and Body Systems

Instructional Sequence

Assessment Types at
This Stage

Assessment Description

Learning Target

Engage

Predictions and Observations: Students’ background knowledge about what needs energy is assessed.  

Students participate in a card sort activity in which they sort cards based on whether they think the object on the card needs energy or not. Students come up with some initial ideas that all living things need energy. 

It is okay if students are unsure about how to best sort the cards. What is important is that students access their prior knowledge and come up with a set of rules for organizing the objects on the cards. 

Explore

Predictions, Observations, and Inferences: Students use a microscope to make observations of living and nonliving things.

Students are introduced to using a compound microscope (optional). Students then explore and compare living and nonliving things viewed through a microscope. Finally, students watch two videos that show the movements of three of the living specimens viewed in the lab. 

Students should be able to

• Draw and record observations of select living and nonliving things viewed under a microscope.
• Identify patterns in the structures of living things.
• Observe living things at a microscopic level and discuss how they all have parts that move. 

Explain

Reading, Group Discussion, Written Responses, and Observations: Students read an article about the characteristics of living things and how living things use energy. 

In this lesson, students read an article about the characteristics of living things. The article outlines the characteristics that all living things share and helps students see how many of those characteristics require energy. 

Students should be able to 

• Explain what structures living things are made of.
• Explain characteristics living things have in common.
• Explain how living things use energy.

Elaborate

Applying Understanding to a New Context: Students’ background knowledge about the relative size of objects is assessed. Students begin to think about how cells in the human body are organized into tissues. 

Students sort cards according to the size of the objects on the cards. The objects on the cards range from as large as a city bus to as small as an atom or molecule. Students engage in a card activity where they take notes about bone, muscle, nerves, blood, skin, fat and small intestinal cells and tissues. Groups answer questions about how living things use energy to make connections to the Culminating Project. 

Students should be able to

• Answer questions about the relative size of cells and why we need microscopes to view cells. 
• Recognize that different types of cells are in multicellular organisms and these cells have different jobs. 
• Explain how living things, including cells, use energy to move, grow, develop, reproduce, respond to stimuli, or maintain stable internal conditions.

Evaluate

Engaging in Argument from Evidence; Understanding, Obtaining, Evaluating, and Communicating Information: 

Students demonstrate their understanding and evaluate their knowledge of how living things are made of cells and how living things and their cells need energy. 

Students engage in a Critique, Correct, Clarify routine in which they must pull apart and correct one possible conception that novices might have regarding what living things are made of and how they use energy. The class updates the Know, Wonder, Learned (KWL) chart with what they learned. 

Students should be able to

• Critique, correct, and clarify a statement about what living things are made of and how they use energy.
• Revisit and add what was learned to the KWL chart. 
• Explain how human cells use energy.
   

Instructional Sequence

Assessment Types at
This Stage

Assessment Description

Learning Target

Engage

Predictions and Observations: 

Students review nutrition labels of common food and drinks. 

Students record their observations of what is in the common food and drinks they consume.

At this point, all answers are acceptable. What is important is that students access their prior knowledge about what is in food that cells could get energy from. 

Explore

Observations and Inferences: 

Students observe a demonstration in which a balloon is inflated by carbon dioxide gas produced by yeast. After the demonstration, students work with a computer simulation of diffusion across a cell membrane.

Students record their observations and collect data. The simulation focuses on the structure and function of a cell membrane.  

Students should be able to 

• Gather evidence and use it to support claims about whether a chemical reaction is happening.  
• Gather evidence that the structure of a cell membrane allows some but not all molecules to pass in and out of a cell. 

Explain

Reading, Group Discussion, and Written Responses: 

Students work with a computer simulation of a yeast cell and read a comic about the behavior of yeast cells. Students then explain what they think happened in the Yeast in a Bottle demonstration. Finally, students read an article about animal cells.

The simulation focuses on the basic structure of a yeast cell and the function of some of the parts of the cell. The comic outlines what students observed in the simulation about how yeast cells get energy and building materials, eliminate waste, and reproduce. Students use information from the comic and the simulation to explain what happened in the Yeast in a Bottle demonstration from the previous lesson. Students then read an article about animal cells. To help students make sense of the reading, students take notes in a table.

Students should be able to 

• Explain what happened to yeast cells in the Yeast in a Bottle demonstration.
• Identify and explain the function of organelles in animal cells, including the cell membrane, nucleus, and mitochondria.
• Explain that sugar moves through chemical reactions that release energy that cells can use.

Elaborate

Applying Understanding to a New Context: Students read about how cells get energy from stored food. Students connect to the Culminating Project by considering what is in caffeinated beverages that cells get energy from.

 

Students read a short article about how the body can store glucose as fat which the body can use for energy. Students record their observations of what is in common caffeinated beverages and then connect to the Culminating Project by answering questions about which of these caffeinated drinks our cells get energy from and explaining their answer.

Students should be able to

• Explain how the body can store food molecules to be used later.
• Explain that cells get energy from caffeinated beverages with sugar and calories but not beverages without. 

Evaluate

Using Models to Show Understanding; Obtaining Evidence and Engaging in Argument from Evidence:

Students demonstrate their understanding and evaluate their knowledge of the basic structure and function of animal cells and how cells get energy from glucose. 

Students engage in a Critique, Correct, Clarify routine in which they correct a statement regarding how cells get energy from caffeine. Students come up with an analogy that compares an animal cell and its organelles to something in everyday life. The class updates the Know, Wonder, Learned (KWL) chart with what they learned. 

Students should be able to

• Critique, correct, and clarify a statement about how cells get energy from what we eat and drink.
• Describe a model of an animal cell using a nonbiological analogy.
• Revisit and add what was learned to the KWL chart. 

Instructional Sequence

Assessment Types at
This Stage

Assessment Description

Learning Target

Engage

Predictions and Observations: Assesses student’s background knowledge about body systems and caffeine.

Students have a group discussion about body systems.

It is okay if students are not sure about the exact nature of different body systems. 

Explore

Observations and Inferences: 

The whole class role-plays what happens to food when it is eaten, digested, and transported throughout the body.

Students reflect on their roles in the class body system role-play. Students also consider how different systems communicate and work together with other body systems to digest food and transport nutrients throughout the body. 

Students should be able to

• Notice patterns in their results.
• Start thinking about the many body parts and systems involved in eating food and how these systems interact and communicate.
• Connect to the Culminating Project through a question regarding what they think happens when caffeine is ingested. 

Explain

Reading, Group Discussion, and Written Responses

Students participate in a jigsaw activity about different body systems working together to communicate and collaborate. Students connect to the Culminating Project by answering questions about how caffeine affects different body systems. 

Students should be able to

• Explain that the body is a system of interacting subsystems composed of groups of cells. 
• Describe how selected human body systems interact with other human body systems.
• Explain the hierarchy of systems in the body: cells, tissues, organs, organ/body systems, organism.
• Explain how caffeine travels through the body and affects different systems in both positive and negative ways.  

Elaborate

Applying Understanding to a New Context: Students build on what they have been learning about how body systems work together by conducting an investigation to study the effect of plant extracts on the heart rate of a Lumbriculus worm. 

In the investigation, students observe and determine the heart rate of a Lumbriculus worm before and after the addition of black tea (containing caffeine). Students use the evidence collected about the worm in the lab and notes from the Explain lesson to provide an explanation of what they think happens to the worm’s cardiovascular, muscular, and nervous systems after ingesting caffeine. 

Students should be able to 

• Generate and record data about a Lumbriculus worm’s response to black tea.   
• Explain how they think the worm’s cardiovascular, muscular, and nervous systems were affected by the black tea. 

Evaluate

Using Models to Show Understanding; Obtaining, Evaluating, and Communicating Information; Engaging in Argument from Evidence: Students demonstrate their understanding and evaluate their knowledge of body systems. Students create a poster that illustrates and describes how the body systems they have studied communicate and collaborate during an activity. Students work on their Group and Individual Culminating Projects.

 

Students create a poster to illustrate and describe how selected body systems they have studied communicate and collaborate during an activity. Students use a Stronger and Clearer literacy protocol to help them refine their thinking and understanding. Students work on their Culminating Project arguments as a group and individually construct a counterargument in the form of a Letter to the Editor. Students provide and receive feedback from a partner about their letters and use the feedback to improve the letters.

Students should be able to 

• Create a poster that includes a diagram with accurate labels and a detailed description of how the body systems interact to complete an activity. 

Group Culminating Project presentations should  

• Address both the risks and benefits of caffeine.
• Give arguments that include evidence gathered during the unit about how caffeine affects human cells and systems in the body.
• Use evidence-based reasoning in their arguments. 
• Provide evidence that shows how at least three different human body systems work together when caffeine is consumed. The body systems students can address in their presentation are limited to the cardiovascular, digestive, muscular, and nervous systems. 

Individual Culminating Project letters should

• Include the same criteria as the Group Culminating Project in a counterargument.
• Be revised and improved based on peer feedback. 

Desired Results

Overview

Through investigations in the Cells and Body Systems Unit, students consider why living things need energy. Students gather evidence to support the concept that all living organisms are made of cells. Students develop and use models to describe the function of a cell as a whole and the ways that parts of cells contribute to the function of the cell, with a focus on how food is broken down through chemical reactions to release energy. The unit focuses on selected parts of cells and how they facilitate collaboration as well as the communication of messages within and between cells. Finally, students explore the concept that all multicellular organisms are complex and organized, as they investigate how the body is a system of interacting subsystems composed of groups of cells. 

Project Tasks

Connections to the Culminating Project Lift-Off: Students watch a video about caffeine consumption. They answer Reflection Questions designed to draw upon their prior knowledge of caffeine, energy, food, and the body. 

Connections to the Culminating Project Subunit 1: Students record what they have figured out about how living things use energy and think about what they need to know next to determine if caffeine can provide energy for our bodies and the cells within them. In the Evaluate lesson, students record what our bodies use energy for and consider how our bodies and cells get energy, if not from caffeine. 

Connections to the Culminating Project Subunit 2: Students look at the nutrition labels of caffeinated drinks with and without sugar to discuss which drinks have substances that cells can get energy from.

Connections to the Culminating Project Subunit 3: Students reflect on their positions for their arguments and work on the Group Culminating Project presentation. Students then work on the Individual Culminating Project, in which they write a counterargument letter and use a peer feedback form to critique one another’s letters. Students have an opportunity to revise their letters based on this feedback.
 

Estimated length of project: 225 min

ESTABLISHED GOALS

MS-LS1-1. Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. . [Clarification Statement: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells.]
 

MS-LS1-2. Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.[Clarification Statement: Emphasis is on the cell functioning as a whole system and the primary role of identified parts of the cell, specifically the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall.] [Assessment Boundary: Assessment of organelle structure/function relationships is limited to the cell wall and cell membrane. Assessment of the function of the other organelles is limited to their relationship to the whole cell. Assessment does not include the biochemical function of cells or cell parts.]
 

MS-LS1-3. Use argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells.  [Clarification Statement: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems.] [Assessment Boundary: Assessment does not include the mechanism of one body system independent of others. Assessment is limited to the circulatory, excretory, digestive, respiratory, muscular, and nervous systems.]

MS-LS1-8. Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories. [Assessment Boundary: Assessment does not include mechanisms for the transmission of this information.]

NGSS Lead States. 2013. Next Generation Science Standards: For States, By States. Washington, DC: The National Academies Press.

ESSENTIAL QUESTION

Should SFUSD ban caffeine? Why or why not?

Students will be able to independently use their learning to

• Construct and present an argument, supported by evidence, for or against the banning of caffeine in the school district.
• Address the counterargument to their group’s position in a letter that is reviewed by their peers. 

Students will know

• Living things are made of many and different cells.
• The function of the cell and its parts.
• How human cells use energy.
• How body systems work together

Evidence

Assessment Evidence

PERFORMANCE TASK: The Great Caffeine Debate

Group Culminating Project: Students work together to create a presentation in which they argue whether caffeine should be banned or allowed in the San Francisco Unified School District (SFUSD). Student arguments must address how interacting body systems are affected when caffeine is consumed. 

The Group Culminating Project will be assessed using the Science Content Rubric, with a focus on the following rows:

• Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. 
• Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.
• Use an argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells.

The Group Culminating Project will also be assessed using the Oral Presentation Rubric. Select one area from this rubric for your students to focus on during their presentations.

Individual Culminating Project: In the Individual Culminating Project, each student addresses the counterargument to their groups’ positions in a letter that is reviewed by their peers.

The Individual Culminating Project will also be assessed using the Science and Engineering Practices Rubric, with a focus on the following rows:

• Engaging in Argument from Evidence
• Constructing Explanations and Designing Solutions
• Developing and Using Models
• Obtaining, Evaluating, and Communicating Information

Learning Plan

Subunit 1

In the Engage lesson, students think about what things need energy and see a pattern that many of those things are living. In the Explore lesson, students watch videos of three living things—amoeba, elodea, and mouse heart—under a microscope and observe how all the cells move, which students infer requires energy. In the Explain lesson, students read an article about the characteristics of living things and why living things need energy. In the Elaborate lesson, students record what they have figured out about how living things use energy and think about what they need to know next to determine if caffeine can provide energy for our bodies and the cells within them. In the Evaluate lesson, students record what our bodies use energy for and consider how our bodies and cells get energy, if not from caffeine. 

Subunit 2

In the Engage lesson, students look at common nutrition labels and think about what is in food and drinks that our cells get energy from, focusing on calories and sugar. In the Explore lesson, students explore a simulation and figure out that large molecules cannot pass through a cell membrane. Students are told that caffeine is a large molecule and infer that it cannot get into the cell. In the Explain lesson, students record an initial explanation for how people get energy from what they eat and drink. Students revise that explanation at the end of the lesson. In the Elaborate lesson, students look at the nutrition labels of caffeinated drinks with and without sugar to discuss which have substances that cells can get energy from. In the Evaluate lesson, students critique,  correct, and clarify an incorrect statement about how cells obtain energy. The class then revisits the driving question board to update with what has been learned in Subunit 2. 

Subunit 3 

In the Engage lesson, students think about how caffeine might interact with various body systems. In the Explore lesson, students do a role-play to figure out what happens when we consume food and drink. In the Explain lesson, students work together on a jigsaw activity, in which they explore how caffeine affects certain human body systems in both positive and negative ways, and revise the role-play activity to include caffeine. In the Elaborate lesson, students conduct an investigation to study the effect of a plant extract containing caffeine on the heart rate of a Lumbriculus worm. In the Evaluate lesson, students reflect on their positions for their argument and work on the Group Culminating Project presentation. Students then work on the Individual Culminating Project, in which they write a counterargument letter and use a peer feedback form to critique one another’s letters. Students have an opportunity to revise their letters based on this feedback. 

Unit Map

Cells and Body Systems

Essential Question: Should SFUSD ban caffeine? Why or why not?

Lift-Off and Introduction to the Culminating Project

 Subunit 1: Living Things Need Energy

Why do living things need energy?

Engage • Explore • Explain • Elaborate • Evaluate

Subunit 2: Cell Structure and Function

How do our cells get energy from what we eat and drink?

Engage • Explore • Explain • Elaborate • Evaluate

Subunit 3: Body Systems Working Together

What happens to caffeine in our body systems? 

Engage • Explore • Explain • Elaborate • Evaluate

Group Culminating Project

The Great Caffeine Debate

Individual Culminating Project

Letter to the Editor
 

Course Concepts

+ Foundational Crosscutting Concepts: These concepts are foundational to the understanding of middle school science. They are present throughout the course. Students are expected to continue to apply their knowledge of the concepts to subsequent relevant projects. 

* Focal Crosscutting Concept: This concept is called out consistently in the Teacher Book and once per subunit in the Student Book. Students will consider the unit project through the lens of this Crosscutting Concept. 

Crosscutting Concept

Unit 1: Energy

Unit 2: Human Impact on Earth’s Climate

Unit 3: Cells and Body Systems

Unit 4: Reproduction and Heredity

Patterns

*

Cause and Effect

+

*

+

+

Scale, Proportion, and Quantity

+

+

Systems and System Models

+

+

*

Energy and Matter

*

Structure and Function

+

Stability and Change

+

Science and Engineering Practices 

+ Foundational Science and Engineering Practices: These practices “carry forward” through the course. Students focus on one of them per unit and are then expected to continue to apply that knowledge to subsequent relevant projects. 

* Focal Science and Engineering Practice: This practice is called out consistently in the Teacher Book and once per subunit in the Student Book. Students will use this practice to complete the unit project. 

Science and Engineering 

Practices

Unit 1: Energy

Unit 2: Human Impact on Earth’s Climate

Unit 3: Cells and Body Systems

Unit 4: Reproduction and Heredity

Asking Questions and Defining Problems 

+

+

Developing and Using Models 

*

+

+

+

Planning and Carrying Out Investigations 

+

+

+

Analyzing and Interpreting Data

+

*

Using Mathematics and Computational Thinking

Constructing Explanations and Designing Solutions

+

+

*

Engaging in Argument from Evidence

+

*

+

Obtaining, Evaluating, and Communicating Information

+

+

+

MS-LS1-1 

Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. [Clarification Statement: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells.]

MS-LS1-2

Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function. [Clarification Statement: Emphasis is on the cell functioning as a whole system and the primary role of identified parts of the cell, specifically the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall.] [Assessment Boundary: Assessment of organelle structure/function relationships is limited to the cell wall and cell membrane. Assessment of the function of the other organelles is limited to their relationship to the whole cell. Assessment does not include the biochemical function of cells or cell parts.]

MS-LS1-3

Use argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells. [Clarification Statement: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems.] [Assessment Boundary: Assessment does not include the mechanism of one body system independent of others. Assessment is limited to the circulatory, excretory, digestive, respiratory, muscular, and nervous systems.]

MS-LS1-8 

Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories. [Assessment Boundary: Assessment does not include mechanisms for the transmission of this information.]

Misconception 

Accurate Concept

Caffeine is “good” for the body. Caffeine is “bad” for the body. 

Much research is still being done on both the risks and benefits of caffeine consumption. The toxicity of any substance is based on many factors, including how much of a substance is consumed as well as the age and overall general health of the consumer. In this unit, students are encouraged to focus on possible risks and benefits of consuming products that contain caffeine based on evidence they gather.  

Caffeine provides the body with energy.

Caffeine has many metabolic effects on the body, yet caffeine molecules do not provide calories for the body. Caffeine itself is not directly converted into energy by cells in the body. What people often mean when they say that caffeine “gives them energy” is that caffeine makes them feel like they have more energy because of its stimulant effects. Caffeine can cause a person to feel more awake and mentally alert, but this is not a result of cells converting caffeine molecules into energy. 

Misconception 

Accurate Concept

Some living parts of organisms are not made of cells (AAAS Project 2061, n.d.).

From American Association of the Advancement of Science (AAAS) Misconceptions (http://assessment.aaas.org/misconceptions/CEM003/281)

The living parts of living things are made of cells, such as skin on a human or the leaves of a plant. When viewed under a microscope, evidence can be provided to show that these parts of living things are made of cells. 

There is no such thing as an organism made of a single cell (AAAS Project 2061, n.d.).
 

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/CEM005/281)

There are both unicellular and multicellular organisms. 

All cells look the same (AAAS Project 2061, n.d.). 

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/CEM001/281)

There are many different types of cells. Cells can have different shapes and sizes to perform their specialized functions. 

Misconception 

Accurate Concept

Cells are only filled with air or water (AAAS Project 2061, n.d.). 

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/CEM008/282)

Cells are made up of molecules, including water and other molecules. These molecules are responsible for the structure and function of the cell. In this unit, students will be responsible for recognizing and understanding the role of selected substructures of cells including the nucleus, mitochondria, and cell membrane. 

All the cells in an organism do not need food or a way to eliminate waste. (This could also be about other basic life processes that all cells share.) (AAAS Project 2061, n.d.)

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/CEM009/282)

All cells share certain basic characteristics and life functions such as converting food to energy, making materials for growth, and eliminating waste.  

Misconception 

Accurate Concept

There is no connection between the digestive system and the cardiovascular system in the body (Buckley, 2000; Carvalho et al., 2004). 

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/BFM028/185-188)

The body is a system of interacting subsystems that are composed of groups of cells. As an example, food is broken down into smaller molecules by the digestive system, and these molecules enter the cardiovascular system through capillaries in the digestive tract.  

Food is broken down into molecules in the body, but these molecules do not enter cells.
 

From AAAS Misconceptions (http://assessment.aaas.org/items/BF133001#/0)

Some molecules in food such as simple sugars are already small enough to enter cells. Other food molecules must be broken down into smaller molecules in the digestive system. Some of these molecules are transported by the cardiovascular system to different cells in the body. Some of the molecules are eliminated as waste. 

Permanent

Consumable

Teacher Provided

• Compound microscope (8)
• Table salt slide (8)
• Baking soda slide (8)
• Amoeba proteus slide (8)
• Elodea slide (8)
• Human heart slide (8)
• Box of blank slides (1)
• Bottle (4)
• Funnel (1)
• Pack of balloons (1)
• Tray (32)
• Safety goggles (32)
• 600 mL beaker (4)
• 50 mL beaker (8)
• Clicker counter (8)
• 25 mL graduated cylinder (8)

• Lens cleaning paper (2) 
• Baking soda box (1)
• Dry yeast (2 oz)
• Sugar (1 lb)
• Dried black tea (150 g)
• Coffee filters (5)
• Transparent tape roll (3)
• Box of cover slips (1)
• Plastic cups (48)
• Pipette (80)
• Lumbriculus worm (8)

• Piece of chart paper (11)
• Large 5"x7" sticky notes (144) 
• Sticky notes (144) 
• Highlighters (32)
• Marker (32) 
• Colored pencils (32)
• Meter stick (1)
• Timer (1)
• Trash can (1)
• Permanent marker (8)
• Balloons (10)
• Masking tape (1 roll)