7.4.2.2 Energy & Matter

Grade: 
7
Subject:
Science
Strand:
Life Science
Substrand:
Interdependence within the Earth System
Standard 7.4.2.2

The flow of energy and the recycling of matter are essential to a stable ecosystem.

Benchmark: 7.4.2.2.1 Photosynthesis

Recognize that producers use the energy from sunlight to make sugars from carbon dioxide and water through a process called photosynthesis. This food can be used immediately, stored for later use, or used by other organisms.

Benchmark: 7.4.2.2.2 Food Webs

Describe the roles and relationships among producers, consumers and decomposers in changing energy from one form to another in a food web within an ecosystem.

Benchmark: 7.4.2.2.3 Matter Transfer in Ecosystems

Explain that the total amount of matter in an ecosystem remains the same as it is transferred between organisms and their physical environment, even though its form and location change.

For example: Construct a food web to trace the flow of matter in an ecosystem.

Overview

Standard in Lay Terms 

MN Standard in Lay Terms

Material and energy move through nature to create a stable environment.

Big Ideas and Essential Understandings 

Big Idea

The flow of energy starts with producers and is distributed through food webs. Plants capture light energy from the sun and through the process of photosynthesis, convert it into chemical (bond) energy. This starts the flow of energy through all biological organisms. Producers, as the entry point for this energy, create complex relationships, allowing the trapped energy to flow from organism to organism, from trophic level to trophic level. Following the flow of energy and bond energy from start to finish, there is a general trend of loss of usable energy and a decrease in biomass of bond energy.

Benchmark Cluster 

MN Standard Benchmarks

7.4.2.2.1

Recognize that producers use the energy from sunlight to make sugars from carbon dioxide and water through a process called photosynthesis. This food can be used immediately, stored for later use, or used by other organisms.

7.4.2.2.2

Describe the roles and relationships among producers, consumers and decomposers in changing energy from one form to another in a food web within an ecosystem.

7.4.2.2.3

Explain that the total amount of matter in an ecosystem remains the same as it is transferred between organisms and their physical environment, even though its form and location change.

For example: Construct a food web to trace the flow of matter in an ecosystem.

The Essentials

©Gary Larson

Correlations 
  • NSES Standards:

Life Science

Content Standard C
As a result of their activities in grade 7, all students should develop understanding of:

 

1.    Structure and function in living systems

2.    Reproduction and heredity

3.    Regulation and behavior

4.    Populations and ecosystems

5.    Diversity and adaptations of organisms

5E The Living Environment :Flow of Matter and Energy

In the middle grades, the emphasis is on following matter through ecosystems. Students should trace food webs both on land and in the sea. The food webs that students investigate should first be local ones they can study directly. The use of films of food webs in other ecosystems can supplement their direct investigations but should not substitute for them. Most students see food webs and cycles as involving the creation and destruction of matter, rather than the breakdown and reassembly of invisible units. They see various organisms and materials as consisting of different types of matter that are not convertible into one another. Before they have an understanding of atoms, the notion of reusable building blocks common to plants and animals is quite mysterious. So following matter through ecosystems needs to be linked to their study of atoms.

Students' attention should be drawn to the transfer of energy that occurs as one organism eats another. It is important that students learn the differences between how plants and animals obtain food and from it the energy they need. The first stumbling block is food, which represents one of those instances in which differences between the common use of a term and the technical one cause persistent confusion. In popular language, food is whatever nutrients plants and animals must take in if they are to grow and survive (solutions of minerals that plants need traces of frequently bear the label "plant food"); in scientific usage, food refers only to those substances, such as carbohydrates, proteins, and fats, from which organisms derive the energy they need to grow and operate and the material of which they are made. It's important to emphasize that the sugars that plants make out of water and carbon dioxide are their only source of food. Water and minerals dissolved in it are not sources of energy for plants or for animals.

By the end of the 8th grade, students should know that

  • Food provides molecules that serve as fuel and building material for all organisms. 5E/M1a
  • Plants use the energy from light to make sugars from carbon dioxide and water. 5E/M1b
  • Plants can use the food they make immediately or store it for later use. 5E/M1c
  • Organisms that eat plants break down the plant structures to produce the materials and energy they need to survive. Then they are consumed by other organisms. 5E/M1de
  • Over a long time, matter is transferred from one organism to another repeatedly and between organisms and their physical environment. As in all material systems, the total amount of matter remains constant, even though its form and location change. 5E/M2
  • Energy can change from one form to another in living things. 5E/M3a

Framework for K-12 Science Education

Plants, algae (including  phytoplankton), and many micro-organisms use the energy from light to make sugars (food) from carbon dioxide from the atmosphere and water through the process of photosynthesis, which also releases oxygen. These sugars can be used immediately or stored for growth or later use. Animals obtain food from eating plants or eating other animals. Within individual organisms, food moves through a series of chemical reactions in which it is broken down and rearranged to form new molecules, to support growth, or to release energy. In most animals and plants, oxygen reacts with carbon- containing molecules (sugars) to provide energy and produce carbon dioxide; anaerobic bacteria achieve their energy needs in other chemical processes that do not require oxygen8LS1.C

Food webs are models that demonstrate how matter and energy is transferred between  producers (generally plants and other organisms that engage in photosynthesis), consumers, and decomposers as the three groups interact—primarily for food—within an ecosystem.  Transfers of matter into and out of the physical environment occur at every level—for example, when molecules from food react with oxygen captured from the environment, the carbon dioxide and water thus produced are transferred back to the environment, and ultimately so are waste products, such as fecal material. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem8LS2.B

Common Core Standards

Students will learn about carrying capacity in social studies as well as various biomes and  ecological succession.

Misconceptions

Student Misconceptions 

Student Misconceptions

  • 7.4.2.2.1, 7.4.2.2.2 Students' meaning for "energy" both before and after traditional instruction are considerably different from its scientific meaning. [1]
  • 7.4.2.2.1, 7.4.2.2.2 In particular, students believe energy is associated only with humans or movement, is a fuel-like quantity which is used up, or is something that makes things happen and is expended in the process. Students rarely think energy is measurable and quantifiable. [2]
  • 7.4.2.2.1 Although students typically hold these meanings for energy at all ages, upper elementary-school students tend to associate energy only with living things, in particular with growing, fitness, exercise, and food. [3]
  • 7.4.2.2.2 Middle- and high-school students tend to think that energy transformations involve only one form of energy at a time. [4]
  • 7.4.2.2.2 Although they develop some skill in identifying different forms of energy, in most cases their descriptions of energy change focus only on forms that have perceivable effects. [5]
  • 7.4.2.2.2 The transformation of motion to heat seems to be difficult for students to accept, especially in cases with no obvious temperature increase. [6]
  • 7.4.2.2.1 Finally, it may not be clear to students that some forms of energy, such as light, sound, and chemical energy, can be used to make things happen. [7]
  • 7.4.2.2.1 Some students of all ages have difficulty in identifying the sources of energy for plants and also for animals. [8]
  • 7.4.2.2.1, 7.4.2.2.2 Students tend to confuse energy and other concepts such as food, force, and temperature. As a result, students may not appreciate the uniqueness and importance of energy conversion processes like respiration and photosynthesis. [9]
  • 7.4.2.2.2 Although specially designed instruction does help students correct their understanding about energy exchanges, some difficulties remain. [10]
  • 7.4.2.2.1, 7.4.2.2.3 Careful coordination between The Physical Setting and The Living Environment benchmarks about conservation of matter and energy and the nature of energy may help alleviate these difficulties. [11]

[1] Solomon, J. (1983). Learning about energy: How pupils think in two domains. European Journal of Science Education, 5, 49-59.

[2] Solomon, J. (1985). Teaching the conservation of energy. Physics Education, 20, 165-170.

Watts, M. (1983). Some alternative views of energy. Physics Education, 18, 213-217.

[3] Black, P., Solomon, J. (1983). Life world and science world: Pupils' ideas about energy. In Marx, G. (Ed.),Entropy in the school: Proceedings of the 6th Danube seminar on physics education (pp. 43-55).

[4] Brook, A., Wells, P. (1988). Conserving the circus: An alternative approach to teaching and learning about energy. Physics Education, 23, 80-85.

[5] Brook, A., Driver, R. (1986). The construction of meaning and conceptual change in the classroom: Case studies on energy. The construction of meaning and conceptual change in the classroom: Case studies on energy..

[6] Brook, A., Driver, R. (1986). The construction of meaning and conceptual change in the classroom: Case studies on energy. The construction of meaning and conceptual change in the classroom: Case studies on energy..

Kesidou, S., Duit, R. (1993). Students' conceptions of the second law of thermodynamics: An interpretive study. Journal of Research on Science Teaching, 30, 85-106.

[7] Carr, M., Kirkwood, V. (1988). Teaching and learning about energy in New Zealand secondary school junior science classrooms. Physics Education, 23, 86-91.

[8] Anderson, C., Sheldon, T., Dubay, J. (1990). The effects of instruction on college nonmajors' conceptions of respiration and photosynthesis.Journal of Research in Science Teaching, 27, 761-776.

[9] Anderson, C., Sheldon, T., Dubay, J. (1990). The effects of instruction on college nonmajors' conceptions of respiration and photosynthesis.Journal of Research in Science Teaching, 27, 761-776.

[10] Anderson, C., Sheldon, T., Dubay, J. (1990). The effects of instruction on college nonmajors' conceptions of respiration and photosynthesis.Journal of Research in Science Teaching, 27, 761-776.

[11] Anderson, C., Sheldon, T., Dubay, J. (1990). The effects of instruction on college nonmajors' conceptions of respiration and photosynthesis.Journal of Research in Science Teaching, 27, 761-776.

Vignette

Students were running around the gym with paper lunch bags collecting 3cm paper squares. Most of the squares were white but some of them were cut from colored paper.

            "Shrews! Go!" Shouted Mr. R.

            Another set of students raced out onto the floor, tagged the other students on the shoulders. When tagged, the students carrying the bags handed the bags to the shrew students. The hunt continued for 15 seconds.

            "Hawks! Feed!" Shouted Mr. R.

            Three hawks "flew in" from the sidelines. Tagging the shrews, who handed over their collections of grasshopper feeding bags.

            "Stop!" you heard Mr.R holler.

            The frenetic activity stopped.

            Twenty grasshoppers had started the activity. One lone hopper remained. Six shrews had fed upon the insects, two survived the hawks' attack.

            Jasper, a hawk, raised his hand, full of paper sacks. "I've got eight stomachs! And man am I full!"

            It took a minute to de-escalate the class, but Mr. R got the students on the floor of the gym sitting still. They debriefed about what it was like to be a hopper, shrew or hawk. Then the class transitioned back to the classroom.

            When they got back to the room, Mr. R asked the to sit in their lab groups. Only three of the groups had a hawk and each had multiple "stomachs" in hand. Mr. R then rearranged the groups so they were clustered around those with hawks.

            "Dump out the contents of your stomachs. What do you notice about the contents of each stomach?" he asked.

            Taylor raised her hand, "There are different colored squares, most of them are white but there are a few multi-colored pieces too."

            "You need to count the squares and keep track of how many are white and how many are colored." R instructed. A collective grown spread across the room. "You know science can be hard work sometimes, so work hard." Mr. R encouraged.

            The students started making piles of their squares.

            "What do the squares represent?" probed Mr. R.

            "They are food." Austin replied.

            "But why are there different colors? And why are most of them white and only a portion multi-colored?"

            There was a pause in the classroom.

            Hans lifted his hand, "I think it shows the different things they eat. The white is one thing and the colored squares are something else?"

            "That's correct. The white is the majority of what grasshoppers eat. What do they eat? What is their diet made of?

            "Grasshoppers eat leaves. I've seen them in my garden eating leaves," reported Rachel. "So, maybe the different colors are different plants."

            "In a food web, how do these organisms, the grasshopper, the shrew and hawks fit together?" probed Mr. R.

            This lead into a discussion about producers and consumers, the various levels of each in a food web. There was also another discussion about pyramids and how food wound its way to the top of the pyramid from the base.

            "Where does this web start?" asked Mr. R.

            "It starts with the grasshoppers," said Amanda.

            Torrie countered, "No, it starts with the food the grasshoppers have eaten."

            Jose then chimed in, "I think it starts with the sun, remember the plants get their energy from the sun."

"Great thoughts, but what if I told you the multi-colored squares represented pesticides. What are pesticides?"

            Torrie answered, "My dad sprayed our bushes in front of the house with pesticide, he said, 'cause they were being eaten by bugs."

            "So, what did the pesticides do to the bugs?"

            "It killed them dead," replied Torrie.

            "Gina, you were the lone hopper left. How many white and colored squares did you have in your bag?"

            Gina answered, "I had 140 white squares and 30 colored ones."

            Mr. R said, "I'm sorry Gina, if you were a grasshopper that ate 30 colored squares, you would be dead. Those colored squares represented pesticide and that level would kill you."

            "AHHHH," Gina gasped as she grabbed her throat. Everyone laughed.

"Tim and Henry, you were surviving shrews. How many stomachs did you have?" asked Mr. R.

            Tim replied, "I twisted my knee in gym class. I only got one hopper and I had 110 white and 20 colored squares. Did I make it?"

            "You survived!"

            Hank answered, "I caught four hoppers and had around five hundred white squares. I got tired of counting them, but I know that I had 150 colored squares."

            "Bummer for you, I'm afraid that you've expired." Mr. R informed Henry.

            "Why did I die and Tim didn't?" Hank demanded!

            "Why do you think that Henry died and Tim made it out alive?" Mr. R posed the question to the class. "Talk with your lab mates and come to an answer."

            The class erupted into a discussion. In half a minute, Mr. R brought them back to focus. "Okay, what are some ideas?" And the class went on to discuss the difference between Tim and Henry's condition. Eventually, the fact that Henry had more pesticide than Tim was the conclusion. Even though they were both shrews, the amount of toxin was different.

            "Hawks let's hear it. What about your results?"

            The class continued looking at data and results, which hawks lived or not. The level of pesticide and the food web location was the focus of the remainder of the class.

            Eventually, the students worked their way to the idea of biomagnification. The farther up the food web the pesticide went, the more concentrated it became, leading to dire consequences for those organisms at the top trophic levels. The students were able to play act the food web, and come back to deal with quantifiable data, come to conclusions based on those numbers.

            This activity was taken from Project Wild copyright 1983, 1985 Western Regional Environmental Education Council.

Resources

Instructional Notes 

Suggested Labs and Activities

Instructional Resources 

Instructional Suggestions/Options

  • Decompostion Columns from Bottle Biology Learn how to explore science and the environment with soda bottles and other recyclable materials.
  • Project Wild: Muskox Manuevers. Students role play wolves and musk oxen in this outdoor look at behavior and predator prey relationships.
New Vocabulary 

Vocabulary/Glossary

  • Consumer: organism that relies on other organisms for energy and food supply; also called heterotrophs.
  • Producer: an organism that synthesizes energy-rich organic compounds from sunlight.
  • Decomposer: organism that breaks down and obtains energy from dead organic matter.
  • Predator: an organism that captures and feeds on another organism.
  • Prey: an organism that is captured and fed upon.
  • Migration: seasonal behavior resulting in the movement from one environment to another.
  • Water cycle: the continuous movement of water on, above and below the surface of the Earth.
Technology Connections 
  • Internet connections if possible, to go online and find pictures to create food webs.
  • Cameras/flip videos/microscopes/ to use on a field investigation to take pictures to use for creating a food web.
  • web-based Journey North  A global study of wildlife migration and seasonal change.
  • Hardware cameras that connect to microscopes would enable class to see chloroplasts streaming in elodea leaves to see how the sun is the source of energy for all things. 
Cross Curricular Connections 

social studies connection with biomes, and how abiotics affect biotic factors. 

References 

Additional Resources

Activities from Bottle Biology Learn how to explore science and the environment with soda bottles and other recyclable materials. Create Decomposition Columns to Bottle Gardens: (lots of activities using pop bottles)

Assessment

Assessment of Students

  • Formative Assessment:          

Evaluation: Draw a diagram of a food web.

Application: Using yarn and pictures of plants and animals, glue the animals to a piece of poster paper. Have students use the yarn to demonstrate the flow of energy through the web.

Recall: List three composers, producers and consumers.

  • Summative Assessment;

Evaluation: Ask students to write a paragraph in response. Consider and discuss the possible reasons for use of pesticides. What are some of the tradeoffs? What are some of the consequences?

Recall: Which of the following organisms would be a producer?

     a. deer c. eagle   b. grass    d. cows

your answer.

Assessment of Teachers

  • How are you going to provide access to nature in your setting? Not everyone has a nature preserve across the street.
  • How can you make this standard relevant to your students and their social and cultural background?
  • If you do not have access for your students to nature, can you bring nature in?

Differentiation

Struggling Learners 

Struggling and At-Risk:

  • Snow, D. (2003). Noteworthy perspectives: Classroom strategies for helping at-risk students (rev. ed.). Aurora, CO: Mid-continent Research for Education and Learning.
  • In 2002, McREL conducted a synthesis of recent research on instructional strategies to assist students who are low achieving or at risk of failure. From this synthesis of research, McREL identified six general classroom strategies that research indicates are particularly effective in helping struggling students achieve success.
  • Hands on labs like the one in the vignette helps special ed students comprehend concepts better than straight book work.
English Language Learners 
  • Herr, N. (2007). The sourcebook for teaching science. This page contains strategies to help teachers better attend to the needs of their ELL learners. These strategies are grouped according to the following learning tasks:listening, visualiza tion, interpersonal communication, laboratory, demonstrations, reading and writing, instruction and vocabulary.
  • Power points or posters constructed in duel languages would help ELL students.
  • Pictures of food webs would be acceptable.
Extending the Learning 

G/T: 

  • Teachers First is an educational support website that may help with G/T students
  • Cogito is another website that is available for G/T Students.
  • Gifted students may create more in-depth food webs.
Multi-Cultural 
  • Science education should include the use of culturally relevant content.  Atwater and Black (Ferguson, Robert. "If Multicultural Science Education Standards' Existed, What Would They Look Like?." Journal of Science Teacher Education. 19.6 (2008): 547-564. Print.)  have proposed several ways to integrate culturally relevant content into the curriculum.  The value of using such approaches is that they can improve the conversation about beliefs in science and hone beliefs about science for all students.
  • Multicultural science education.  Official NSTA Position Statement.
  • Freelang.net hosts a English to Ojibwe and Ojibwe to English dictionary that may be used to look up meanings to vocabulary words.
  • Activities like those in the vignette would help students
  • Pictures of food webs would be acceptable. With duel labels
Special Education 
  • Technologies for Special Needs Students: In their newsletter, "Tech Trek",  from the National Science Teachers Association, there are suggestions for using technology including voice recognition software.
  • Hands on labs like the one in the vignette helps special ed students comprehend concepts better than straight book work.
  • Pictures of food webs would be acceptable.

Parents/Admin

Classroom Observation 

Administrators

There should be a lot of outside activities with this standard. Rural, suburban and urban settings are full of nature. Teachers need to access any corners of the campus to get outside and to address the nature deficit.  Louv, R. (2008). Last child in the woods. Chapel Hill: Algonquin Books.  The author correlates the trend that children are spending less time outdoors, resulting in a wide range of behavioral issues. 

Parents 
  • Parents:  students maybe talking about food webs at home.
  • Parents could see posters come home.