Beacon Lesson Plan Library

Dirty Worms

April Martin

Description

Students will learn the actions of earthworms and their effect on soil. The lesson will culminate with an earthworm dissection lab activity.

Objectives

The student knows ways that plants and animals reconstitute the soil and alter the landscape.

The student uses appropriate procedures for safety in the classroom, home, and community.

Materials

-Earthworms *
-Dissecting pans*
-Dissecting pins*
-Dissecting scissors*
-Teasing needles*
-Forceps (aka tweezers)*
-Magnifying glass*
-Safety goggles*
-Lab aprons*
-Alcohol prep pads or sterilizing wipes(optional)*
-Paper towels
-Copies of an Earthworm Diagram for each student
-Copies of Earthworm Dissection Instructions for students in each lab group
-Copies of the Earthworm Dissection Procedural Checklist and Cooperative Learning Checklist for each student
-Copies of Lab Safety Checklist for each student
-Pencils
*Earthworm dissection materials can be ordered/purchased through a Science Supply Catalogue.

Preparations

1) Order/purchase/obtain the earthworm dissection materials.
2) Using the internet or science reproducible book, make copies of the diagram of an earthworm.
3) In each dissecting pan place 2 paper towels, 2 teasing needles, one pair of dissecting scissors, one forceps, one magnifying glass, one cup of dissecting pins (approximately 24), 4 pair of safety goggles, 4 aprons, and 4 earthworm diagrams.
4) Place the materials either at each lab group station or in a specific location which is easily accessible to students.

Procedures

Day One
1) Ask students, -Can anyone explain why earthworms are very, very important to us?- Allow several students to share their answers, then lead them in a discussion of the importance of earthworms. Make sure students understand that earthworms tunnel through the soil, ingesting (eating) it as they go through the soil. (The soil goes in one end of the worm and comes out the other!) This action of the earthworm breaks the soil down which allows water to flow through the soil easily (which improves drainage) as well as breaking the soil up to make it richer and easier for plants to grow - including food.

2) Following the discussion, tell students they are going to work in groups of 4-5 to participate in an earthworm dissection lab activity.

3) Explain/review lab safety procedures with students. (Lab safety procedure review should include the importance of wearing lab aprons to protect clothing, wearing safety goggles to protect eyes, no horseplay in the classroom, be very careful as sharp instruments are being used, wait until the teacher tells you to start before you beginning the actual activity, report any accidents or injuries to the teacher, do not taste or put any lab equipment in the mouth, and clean up your lab area at the end of the lab activity.) Tell students to make sure they complete, sign, and date their Lab Safety Checklist at the end of the lab activity (in attached file).

4) Review with students the rules for working in cooperative groups, and assign specific jobs to members of each group. (Group Leader, Recorder, Supplies Manager, and remaining will be group members.) Tell them they are to each participate, not just watch the others in their group. They should also value each others thoughts and opinions without making fun of anyone in the group. No -put downs- are allowed and should be reported to the teacher. Stress that each student should participate and no one student should try do everything by him/herself. Tell students they will complete the Earthworm Dissection Procedural Checklist, Cooperative Learning Checklist and Lab Safety Checklist during and at the end of the lab activity (in attached file). However, the recorder should complete these checklists during the activity to make sure the information is correct.

5) If students are not already seated in groups, assign students to their groups. If lab materials have not already been placed in the middle of lab tables, ask one student from each group to go to the appropriate area to obtain the lab materials for their group. Pass out one worm to each group at this time.

6) Instruct students to look at their earthworm dissection sheets (in attached file) which were included in their lab materials, and go over the directions with them. Any student questions should be answered during this instruction. Tell students that when you give them the signal to begin they activity, they will follow the directions on their own but should ask you, the teacher, should they have any questions or difficulties.

7) Tell students they may begin the activity and that when they finish, they should complete the Earthworm Dissection Procedural Checklist, Cooperative Learning Checklist, and the Lab Safety Checklist. These should be turned in to the teacher at the end of the class period.
8) While the students are working, walk around the class in order to observe groups, keep students on task, and offer assistance as needed. (The teacher may want to use a copy of the Procedural Checklist as he or she monitors each group to make sure they are following directions.)
9) At the end of the class, collect all checklists and make sure students have returned materials to the appropriate place, and cleaned up their lab areas. Give instructions on how to clean or what to do with the goggles so they will be sterilized in time for the next class. (One suggestion is to wipe them down with alcohol prep pads/wipes.)

10) Either at the end of this class period or the beginning of the next time this class meets, orally review with students how worms reconstitute the soil, how they can change the landscape, and why they are important to us.

Assessments

Formative assessment consists of the following documents in the attachment:
1) Earthworm Dissection Procedural Checklist and Cooperative Learning Checklist *
2) Lab Safety Checklist*
* For grading purposes you could either give them a 100 for completing each checklist, combine both checklists and grade them together, or simpy check them off when completed and turned in to the teacher.

Extensions

As an extension of this activity, the teacher may want to have the class do a composting activity using leaves, old newspapers, food scraps, and earthworms. The Internet is a good resource for specific instructions on how to compost.

Web Links

Interesting Worm Information website for kids
Worm World

Return to the Beacon Lesson Plan Library.