UNIT TITLE: Exploring Ecosystems

GRADE LEVEL: 5th grade

LENGTH OF UNIT: 10 weeks

SECTION 1: Key Ideas and Major Understandings

Individual organisms and species change over time.

  1. In all environments, organisms with similar needs may compete with one another for resources. (3.2a)
  2. Extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient to permit its survival. Extinction of a species is common… (3.2b)
  3. Although the time needed for change in a species is usually great, some species of insects and bacteria have undergone significant changes in just a few years. (3.2d)

Organisms maintain a dynamic equilibrium that sustains life.

  1. Animals and plants have a great variety of body plans and internal structures that contribute to their ability to maintain a balanced condition. (5.1a)
  2. An organism’s overall body plan and its environment determine the way the organism carries out the life processes. (5.1b)
  3. The methods for obtaining nutrients vary among organisms. Producers, such as green plants, use light energy to make their food. Consumers, such as animals, take in energy-rich foods. (5.1d)
  4. Herbivores obtain energy from plants. Carnivores obtain energy from animals. Omnivores obtain energy from both plants and animals. Decomposers, such as bacteria and fungi, obtain energy by consuming wastes and/or dead organisms. (5.1e)
  5. The survival of an organism depends on its ability to sense and respond to the external environment. (5.1g)

Plants and animals depend on each other and their physical environment.

  1. Energy flows through ecosystems in one direction, usually from the Sun, through producers and consumers and then to decomposers. This process may be visualized with food chains or energy pyramids. (6.1a)
  2. Food webs identify feeding relationships among producers, consumers, and decomposers in an ecosystem. (6.1b)

Human decisions and activities have had a profound impact on the physical and living environment.

  1. A population consists of all individuals of a species that are found together at a given place and time. Populations living in one place form a community. The community and the physical factors with which it interacts compose an ecosystem. (7.1a)
  2. Given adequate resources and no disease or predators, populations (including humans) increase. Lack of resources, habitat destruction, and other factors such as predation and climate limit the growth of certain populations in the ecosystem. (7.1b)
  3. The environment may contain dangerous levels of substances (pollutants) that are harmful to organisms. Therefore, the good health of environments and individuals requires the monitoring of soil, air, and water, and taking steps to keep them safe. (7.1e)
  4. Overpopulation in any species impacts the environment due to increased use of resources. Human activities can bring about environmental degradation through resource acquisition, urban growth, land-use decisions, waste disposal, etc. (7.2c)
  5. Since the Industrial Revolution, human activities have resulted in major pollution of air, water, and soil. Pollution has cumulative ecological effects such as acid rain, global warming, or ozone depletion. The survival of living things on our planet depends on the conservation and protection of Earth’s resources. (7.2d)

SECTION 2: Essential/Unit Questions and Skills

Essential Questions:

  1. How do living and nonliving things interact?
  2. How do adaptations help organisms?
  3. How do environmental changes affect species?
  4. What is the role of humans in an ecosystem?
  5. Why is it important to study food webs and ecosystems?

Unit Questions:

  1. What are adaptations?
  2. What are structural adaptations? Identify them and state their functions.
  3. What are behavioral adaptations? Identify them and state their functions.
  4. What adaptations help organisms survive in a water environment? On land?
  5. What adaptations help organisms survive seasonal changes?
  6. What are individuals, populations, communities, and ecosystems?
  7. What is the difference between biotic and abiotic factors?
  8. What are examples of different biomes? How are they similar/different?
  9. What is the role of producers in an ecosystem?
  10. How do consumers/decomposers get the energy and nutrients they need?
  11. What do food chains and food webs show about energy flow?

Living Environment Skills:

  1. Interpret and/or illustrate the energy flow in a food chain, energy pyramid, or food web.
  2. Identify structure and function relationships in organisms.

SECTION 3: Assessments and Targets

Diagnostic Assessments:

  1. K-W-L chart – Given at the start of the unit to provide an informal assessment of what students know about ecosystems and what they wish to learn.
  2. Pre-Unit Test – A formal assessment of students’ knowledge. This test will cover relevant standards in the Elementary Science Core Curriculum (K—4th grade).

Formative Assessments:

1. Student-teacher conferences and checklists.

2. Whole-class discussions at the end of lessons.

3. Reflection logs – Students will complete daily reflections throughout the duration of their research projects.

4. Students will be assessed throughout several learning experiences, such as:

a. Sort ecosystem cards according to ecological organization levels

b. Determine the effect of sunlight on plant growth

c. Observe the behavior and response of earthworms

d. Watch Jane Goodall’s famous observational study of chimpanzees

e. Identify the structures and function of snails, crickets, anoles, and “Betta fish”

f. Dissect owl pellets and construct a food chain

Note: For the complete list of learning experiences, see Section 8: Schedule of Lessons.

Summative Assessments:

1. Individual research reports on different ecosystems.

2. Group PowerPoint presentation.

3. Post-Unit Test – Formally assess students’ mastery of unit standards and skills.

4. End-of-unit reflection – Informal assessment of students’ progress and dispositions.

SECTION 4: Unit Vocabulary

Organism / Adaptation / Fungus/fungi
Habitat / Behavioral adaptation / Behavior
Camouflage / Structural adaptation / Structure
Individual / Function / Degrees Celsius (ºC)
Population / Evolution/evolve / Thermometer
Community / Species / Prey
Ecosystem / Pollution/pollutants / Predator
Biotic factors / Acid rain / Dissect
Abiotic factors / Global warming / Overpopulation
Food chain / Extinction / Hibernation
Biome / Survival / Mimicry
Producers / Carnivores / Migration
Consumers / Herbivores / Primary consumer
Decomposers / Omnivores / Secondary consumer
Food web / Regulation / Third-level consumer
Advantage / Reproduce
Disadvantage / Resource

SECTION 5: Achievement Targets and Assessment Methods

Achievement
Target / Selected
Response / Essay / Performance
Assessment / Personal Communication
Knowledge & Understanding / • Multiple-choice questions from previous State Science Exams.
•Vocabulary
fill-ins (Do Nows). / • Various essay exercises throughout the unit.
• Essays included in post-unit test. / Other methods are preferable. / • Whole-class discussions at the end of lessons.
• Student-teacher conferencing and checklists.
Reasoning
Proficiency / Other methods are preferable. / • Students explain the relationship among the different levels of a food web. / • Observe/assess students creating food webs. / • Ask students to “think aloud” and ask followup questions to probe reasoning.
Performance Skills / Other methods are preferable. / Other methods are preferable. / • Observe and evaluate group PowerPoint presentations. / • Assess oral communication skills during group presentation.
Ability to Create
Products / • Students will complete checklist to ensure completion of their projects. / • Brief essay to assess mastery of standards prior to start of research project. / • Construct food web diagram.
• Create individual research report on an ecosystem and its organisms. / • Probe procedural knowledge during group presentations (e.g., How did you obtain this information?).
Dispositions / Other methods are preferable. / • Open-ended questionnaire at the end of unit (reflection piece). / • Can infer dispositions from behavior and products (anecdotals). / • Ask students why ecosystems are worth studying.

SECTION 6: Possible Misconceptions and Solutions

Students may believe that…

  1. All plant and animal species have been discovered. Discuss how new species are being discovered frequently (especially insects). Do a shared reading of the article More than 1,000 Species Found in Mekong.
  2. An individual plant or animal can suddenly develop a new adaptation during its lifetime.Address this issue during the Walking stick lesson. Students will perform an online investigation to explore how successive generations of walking sticks survive or become extinct due to their protective coloration.
  3. Animals behave the same way that humans do. For example, students observing a population of crickets may state: “They are playing together.” Students must learn to distinguish facts and opinions when writing observations. Address this problem when students are completing observation logs for their terrariums and aquariums.
  4. Animals that eat other animals are being “mean” or “evil.” Explain that it is necessary for all living things to obtain nutrients and carry out their life processes. Do a shared reading of the article Why Some Animals Are Considered “Bad” or “Scary.”
  5. All desert ecosystems are hot. Even deserts that are hot during the day can become uncomfortably cold at night. One group of students will research desert biomes. Ask them to address this issue in their presentation to the class.

SECTION 7: Statement of Purpose

Introduction

It is clear that this unit, Exploring Ecosystems, is not intended to be cursory. It is, in fact, a careful amalgamation of two major units – Food Chains and Webs and Populations and Ecosystems – created by Delta Education. These two units served as a supporting backbone on which to build my lessons. I would like to stress that none of these lessons have been copied straight from the Teacher’s Guide. Every single one has been altered, expanded, or improved in order to meet the specific needs of my students. It is my personal belief that cookie-cutter worksheets are rarely (if ever) appropriate. Therefore, all the worksheets and graphic organizers that my students receive are created from scratch and often differentiated by academic level or language proficiency.

The first thing this unit does is it attempts to bridge the scientific knowledge from the elementary grades into middle school. Thus, it begins with a diagnostic assessment of students’ mastery of elementary concepts regarding the living environment in order to tailor the lessons to the students’ needs. The data gathered from this initial assessment will help the teacher make crucial decisions such as how to build on previous knowledge, expose students to concepts they have possibly never been taught, and determine which lessons can be taught in small groups rather than the whole class.

Exploring Ecosystems focuses on four key ideas delineated in New York’s Intermediate-Level Science Core Curriculum for grades 5 though 8:

  1. Individual organisms and species change over time.
  2. Organisms maintain a dynamic equilibrium that sustains life.
  3. Plants and animals depend on each other and their physical environment.
  4. Human decisions and activities have had a profound impact on the physical and living environment.

Each of the four key ideas is then further divided into major understandings (i.e., science standards). These are statements of what students should be able to do to provide evidence that they know the key idea. These standards have been carefully arranged in a chart that will help me formatively assess how each student is progressing in his or her mastery of the standards (see Assessment Chart). Of course, not all of the standards listed in the “Living Environment” section of the Core Curriculum have been covered, as students will learn and revisit more complex and abstract concepts in subsequent grades. For example, as students advance in middle school, they will gradually learn how to do such things as burn food to measure the amount of energy it contains, construct and analyze energy pyramids, and learn the structures and genetic mechanisms of heredity.

To get an idea of how the standards in this unit are presented and assessed in the 8th Grade NY State Science Written Exam, please review “Item 10d – Original Curricular Tool D,” which is a collection of test questions gathered from the past four years. These questions can be used as “Do Nows” at the beginning of lessons, given for homework, or included in the end-of-unit test.

The Research Project

I believe that research projects have a great potential for motivating students and helping them become independent learners. As part of their summative assessment, students will be required to complete a research project on a variety of sensitive ecosystems found across the United States. The goals of this project will be to help students: collect information using different types of primary and secondary sources; locate information using a variety of research strategies; organize information; ask questions to further the investigation of topics; evaluate the information found in documents; and take responsibility for completing individual and group assignments. Of course, the loftier goal is for students to realize that humans are inextricably linked to ecosystems and are ultimately responsible for their protection and conservation.

Experience has taught me that fifth graders are very inquisitive. Their natural curiosity and desire to learn about the world around them are wonderful motivators for teaching research and expository writing. Students at this age also show a preference for nonfiction. Reading nonfiction requires that students practice and hone a set of skills different from reading fiction. In this unit, students will be able to practice literacy skills and strategies, many of which will prove useful on the English Language Arts Test. Also, many of the lessons dealing with research comply with several ELA standards including: comprehending informational materials (E1c), producing a report of information (E2a), and delivering an individual presentation (E3c).

Evolution: The Controversy

Exploring Ecosystems introduces elementary students to the idea of “natural selection,” which can be sensitive and controversial. As we know, the ideas of natural selection and evolution of life on Earth can bring scientific historical evidence and the very essence of scientific inquiry into conflict with deeply held beliefs concerning the sacred origins of life. Both points of view seek to answer the same questions, in a way: how did I get here, and where did I come from? It is worth teaching students that even Darwin himself anguished over his newfound ideas and feared societal response to his propositions.

The intent of this unit is to introduce students to the scientific explanation for the origin of species, and not to disparage their belief system. Students are presented to these ideas and encouraged to engage them in different ways. One possibility is to incorporate persuasive writing and public speaking into this curriculum, encouraging the students to present and defend the various perspectives surrounding this topic.

For some enlightenment on these issues, I recommend the following literature:
• Intelligent Thought: Science Versus the Intelligent Design Movement,
by John Brockman (Vintage Books, 2006).
• The Reluctant Mr. Darwin, by David Quammen (Atlas Books, 2006).

Opportunities for Integration

Various lessons in this unit can be easily integrated with other subjects. For instance, in Lesson 21 the students rely on their math skills as they collect population statistics of walkingsticks and graph their data. In Lesson 16, “The Industrial Revolution,” the students delve into social-studies texts in order to comprehend how human progress can sometimes lead to environmental degradation. Students will also be receiving an implicit lesson in geography as they explore different regions of the United States for their research projects.

Technology has also been incorporated throughout the unit in order to enhance the students’ learning. Students will watch several videos (Among the Wild Chimpanzees, The Vanishing Frog, Voyage to the Galapagos Islands) in order to see science in action in the “real world.” Obviously, the Internet will play an integral part in the research process. Students will learn how to safely and effectively use the web as a source of up-to-the-minute information, as well as how to find and evaluate online sources on their own. Students will have the opportunity to create a multimedia presentation using PowerPoint or Keynote to present their research to their classmates. With the right support, experiences in public speaking can be very valuable in building students’ self-esteem and confidence. It will also help them prepare for their eighth-grade exit projects in science and social studies.

No Child Left Inside

I recently read Richard Louv’s fascinating book, Last Child In the Woods: Saving Our Children From Nature-Deficit Disorder. The book describes the accumulating body of research that reveals that contact with nature is necessary for healthy child development. The less time the young spend in natural surroundings, he says, the more their senses narrow physiologically and psychologically. Louv argues that “reducing that deficit – healing the broken bond between our young and nature – is in our self-interest, not only because aesthetics or just demands it, but also because our mental, physical, and spiritual health depends upon it” (p.3).

Indeed, it is my aspiration as a science teacher to help reduce that deficit. Students need to understand that every bite we take connects us to a complex network known as a food web. At the end of the unit (or perhaps earlier) students should take the opportunity to venture outside to apply the concepts discussed inside the classroom. One possibility is to take the kids to Ft. Tryon Park, where the Cloisters Museum is located (yet another opportunity for the integration of social studies!). Here they can observe and study a local ecosystem with the aid of digital cameras, notebooks, and binoculars. But beyond teaching them to be passive observers, children should be encouraged to become active citizens and devise ways to reduce the negative impact of humans on the natural environment (e.g., create an anti-littering campaign or schedule a community clean-up).

As we know, many of our school are situated in challenging urban environments where it is not always possible (or safe) to venture out into nature, so it’s up to us to bring nature to the students. One way of doing this is by helping students build aquariums and terrariums for study. The children are always fascinated and excited when introduced (some for the very fist time) to live animals like crickets, anoles, earthworm, Betta fish, aquatic snails, and more. It is my hope that through these hands-on experiences my students will become the future Jane Goodalls and Jeff Corwins of the world.

Created by A. Pérez – March, 2009