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Seventh Grade Life Science

Background

I took over the three seventh grade life science classes as a long-term substitute from the end of March 2002 to the beginning of May. The students had just completed a unit on evolution and adaptations, and began a unit on ecology and environmental science. I had never worked with middle school students in a classroom setting before, and I was unsure at what level I could expect them to perform. Therefore, I wanted to keep my lesson plans simple and flexible so that I would have a chance to assess the students’ from a number of perspectives and be able to adapt depending on what I learned.

Search

I also needed to keep my lessons simple without much homwork because all of the seveth graders were beginning long-term, indpendent Search projects. Students at Friends Select undertake two of these projects each year from fifth through eighth grade. Seventh grade Search focused on Math, Science and Sports in Spring 2002. Each student chose a topic related to Math, Sience and Sports (i.e The Physics of Skateboarding, Gender and Basketball, or Heat and the Bounce of a Tennisball). Students were responsible for researching their topic, designing and conducitng a primary investigraion (experiment, interview, construction of a model etc.), analyzing their results, writing a full-length narrative and finally, designing and presenting a visual display of their Search at the school's Math and Science Symposium.

As the science teacher, I was responsible for being a Search Advisor to one science class of fifteen students. My role was to provide support and guidence to this group of students as they worked their way through the two-month Search process. I used two 40-minute class periods a week to talk with students about their Searches and for students to work on their experiments and research. I guided students through the scientific process, helping them to construct questions and hypoheses, to design strong, simple, but elegant experiments and to think about their data and results from multiple perspectives. I also read and gave feedback on students' Search journals which summarized their notes, thoughts and results they were required to turn in each week. Finally, I supervised students' final presenatations and read and graded their narrative reports.

 

Tennis, Temperature and Surface

Model of a Hockey Rink
(How the design of hockey rinks affects the game)

Gender and Basketball

Sample Lesson: Introduction to Ecological Concepts

Taking an Ecosystem Snapshot
Triangle Park - the urban ecosystem my class studied

Goals

My goals for the first lessons that I did with the 7th grade science students were that the lessons:

  • be engaging.
  • demonstrate the basic principles and concepts of ecology, while using some elements of the scientific method.
  • apply these concepts to a local, urban ecosystem.
  • be simple and straightforward, allowing all students in the class to experience success.
  • allow me to observe students working together and independently under a variety of conditions.

Objectives

  • All students will understand the meaning of the terms ecology, ecosystem, environment, community and habitat.
  • All students will be able demonstrate their understanding by using the above terms in complete, original sentences that make the meaning of the term apparent without defining it directly.
  • All students will understand that organisms in ecosystems are connected through relationships to their living and non-living environment.
  • All students will demonstrate this understanding by making lists of living and non-living things in their own school yard environment and examples of relationships between these organisms and their living and non-living environment.
  • All students will be able to list and characterize the living and non-living components of a local, urban park ecosystem and the relationships between these components.

Lesson 1: Introduction to Ecological Concepts (40 min.)

  • When the students enter the classroom, the following terms are written at the board: ecology, ecosystem, environment, community and habitat.
  • Once the students are seated and ready for class, ask them to work in the groups of four they are seated together with at round tables to come up with definitions for the words on the board. Ask them to have one person write down the definitions as the whole group comes to agreement (10 min).
  • Bringing the whole class back together, go through the terms and ask students to share their definitions. Allow students to agree, disagree and make changes in each other’s definitions. As the teacher, correct any misconceptions and help to refine students’ definitions that may be too incomplete, narrow or broad. Write the most complete definitions on the board (10 min).
  • Tell the students that these terms are related and that we are going to make a concept map to show the relationships. Again, ask the students in their groups to create a concept map of the terms (10 min).
  • Bringing the class back together, ask one person from one group to come to the board to share their concept map. Ask if other groups had any other ideas or if they would make any changes to the map on the board. Discuss the relationships and ask the students to give examples from their own personal experiences that demonstrate the relationships illustrated in the map (10 min).
  • Make sure that all students have the final versions of the definitions and concepts maps in their notes.

Homework

  • Read pages _ in the text (an introduction that covers the same vocabulary and concepts introduced in the lesson). Use the following terms in complete and original sentences that demonstrate your understanding of their meaning without directly defining them:
    • ecology
    • ecosystem
    • environment
    • habitat
    • community

Lesson 2: Relationships within Ecosystems (40 min.)

  • When students come into the classroom, the following problem is written on a piece of paper, one per table:

    On the South Pacific island of Mauritius, scientists discovered 13 ancient trees, all over 300-years-old, which were the only members of their species surviving on Earth. The scientists were troubled as to why no new trees were growing, since the 13 living trees were still producing big, hard-shelled seeds every year. What is the answer to the puzzle?

    ** Hint, Mauritius is the same island the famous Dodo bird inhabited until it was hunted to extinction by western explorers.

  • Ask students to work together to brainstorm possible answers to the puzzle.
  • After 5 minutes, tell the students that there are many possible answers to the puzzle, but only one correct answer. They may ask yes/no questions of me in order to solve it. Provide additional hints when they get stuck (10 min).

    Answer: The big Dodo birds ate the seeds of the trees (called Dodo trees). The tough digestive system of the Dodo bird broke down the protective hard shells of the big seeds, so that after the seeds passed through the bird, they were able to germinate. When the Dodo went extinct (about 300 years ago), the there were no other large seed-eaters to assume the ecological role of the Dodo, so the Dodo trees continued to produce seeds, but none of them germinated. Scientists came to this conclusion after feeding the Dodo tree seeds to turkeys, who do not inhabit Mauritius, but have similar digestive systems to the Dodo bird. The seeds that passed through the turkey digestive tracts germinated!

  • Once the students have answered the puzzle, ask one student to summarize the explanation in his or her own words. All students should copy the puzzle and the solution (in their own words) into their notes.
  • Ask students how the puzzle provides examples of relationships between organisms and their living and non-living environment (possible examples: Dodo trees rely on Dodo birds for seed germination, Dodo bird was hunted to extinction by humans, Dodo tree recruitment is limited by island geography). Write these examples on the board and ask students to take notes (15 min).
  • Tell the students that you want them to think of similar examples of relationships between organisms and their environment in the students’ own environment.
  • At the board make three columns: Living things, Non-living things and Relationships.
  • Ask the students to brainstorm examples for each category in the city from their own previous observations and experiences. Ask each student to keep a copy of the brainstorm lists in his/her notes (10 min).

Homework

  • Sit outside for 10 minutes during break, lunch or before or after school in the school yard and create a new set of lists like the ones that we made in class today (Living things, Non-living things and Relationships). Make it your challenge to look for new organisms and relationships that you may not have noticed or thought of before!

Lesson 3 (Lab): Taking an Ecosystem Snapshot (80 min)

For modifications of this lesson for students with special needs click here

Introduction

  • When the students enter the classroom, have plant samples and plant identification books set out on the tables where the students sit.
  • Explain to the students that you collected these plant samples from the park across the street where we will be going to carry out our lab today and that you would like them to try to use the books to identify the plants.
  • Give the students 10 minutes to work together in groups to identify the samples, helping them when they get stuck or are wrong.
  • Ask the students to share what they found and the major features of the samples that they used in identifying them. Pass the samples around the room so that all students can see.
  • Make the point that all the plants that they see in the park are not only “grass,” but that there are actually a wide variety of species living and interacting in the small space!
  • Provide students with pictures or samples of any other living species (i.e. birds, trees, insects, small mammals) that they could expect to encounter or see evidence of in the park.
  • Ask the students to take out the observations of the school yard that they made last night for homework.
  • Have students quickly share some examples of their observations.
  • Point out that it is often difficult to see everything in an ecosystem unless you know what you are looking for and look closely.

Lab: Making an Ecosystem snapshot

  • Explain that for lab, we will be taking a close look at an ecosystem.
  • Give students a handout with directions for taking an ecosystem snapshot and graph paper for recording their results. Go over directions to make sure that students are clear as to what they need to do:
  • Lay down a 3 meter transect (using a pre-measured piece of twine) in the park.
  • Record everything living and non-living that touches the transect, marking the distance along the transect that it was found and identifying any living organisms as specifically as possible.
  • Move to another section of the park and repeat the process with another transect.
  • Record three relationships that you see evidence of between organisms found along your transects and other living and/or non-living things in the park environment.
  • Make lists of all other living and non-living things that you see evidence of in and around the park (i.e. humans, buildings, cars, birds, animal holes, ant hills, statues, puddles etc).
  • Explain that transects are a way of trying to be objective about our observations. They force us to notice things that we wouldn’t have otherwise and attempt to give a random and more accurate sample of the park. Ask if students can think of other ways in which to obtain such samples (i.e. square or circle plots, point sampling, using longer and fewer transects etc.).
  • Group students to work in pairs and have them go outside to the park. One pair will measure and draw the boundaries and major physical features of the park, so as to have a context in which to place the transect samples that the rest of the class is creating.
    Allow students to work independently, helping them in identifying species and making observations (30 min).

Homework:

  • Complete lists of living and non-living components of the park ecosystem and examples of relationships.

Lesson 4: Making the Ecosystem Snapshot (40 min).

  • Ask students to make a blown-up diagram of their ecosystem snapshot. Stress that it should be:
    • Neat and legible.
    • Accurate (measurements, identification of organisms).
    • As complete a picture as possible of the park ecosystem.
    • Colorful and creative.
    • Allow the pairs of students to use class time to work on their snapshots.

Lesson 5: Comparing Ecosystem Snapshots (40 min).

  • Allow students to make any final touches on their Ecosystem Snapshots (20 min).
  • Bring the groups together and have them hang up their snapshots at the front of the room. Use the following questions to generate discussion and reflection (20 min):
    • What are the similarities between the snapshots? The differences?
    • What were the major relationships that people observed?
    • What relationships did people see indirect evidence of?
    • Are there any snapshots that look completely different? Where were these transects located?
    • Did the transects allow us to sample all the living and non-living things in the environment?
    • What was useful about the transect sampling technique? What was not useful?
    • How could we change our technique if we did this lab again?
    • If we did this lab again in 3 weeks, what might be different in our observations and how the snapshots look? In three months? In a year? In ten years? In a million years?

Homework

  • Make any final touches or changes on ecosystem snapshots. These will be handed in to be evaluated the next day.


Samples of Student Ecosystem Snapshots, additional work and narratives: