Wormology

Activity Description:

Overview:
Students will investigate the effects of different atmospheric conditions upon three types of worms.

Activity Duration: 50 minutes

Materials:

• Heat source (warm water, hotplate etc.)
• Acid rain mixture
  (20 ml of 0.1 M HCl to 2 liters of water)
• Basic glassware (graduated cylinders, beakers)
• 30 of each type of worm
  • Planaria
  • Earthworm
  • Mealworm
• Small paint brushes
• Droppers
• Straws
• String
• Colored light sources
• Thermometers
• Dissecting trays
• UV light source
• Wind sources
• Ice

Background Information:

Each kind of worm has different biological needs, environmental preferences, and adaptations. Each species as well as each individual worm will behave differently when exposed to various atmospheric changes. Stress that each test should be conducted on several worms, so that all data is valid. All worms can be ordered through any scientific supply catalog. Only one type of worm may be used for this activity, but all three kinds will provide a comparison between different forms of life.

Teaching and Learning Strategies:

Ensure Inquiry
Students need to develop their own hypothesis, plan, procedure, and draw their own conclusions. There are many ways in which to solve a problem, and students will learn just as much from failures as from successes. Focus on the process rather than the finished product with this activity. It is a good idea to answer students questions with questions.

Prerequisite instruction

Before this activity begins, teach students about elements of a good science experiment. Animal behavior should not be discussed in advance as it relates to atmospheric changes. Some knowledge of acid rain, ozone, UV light, different wavelengths of light, and other possible atmospheric variables may increase the complexity of the experiments, but it is not essential for this inquiry.

Invitation to Learn:

Problem: How do various atmospheric conditions affect worms (a simple form of life?)

Instructions

1. Put students into groups of four or five
2. Give each group two to three worms of each species.
• Note: Earthworms and mealworms can be kept in some type of container with a few drops of water. Planaria need to be kept in fresh water.
3. Students are to solve the problem (listed above) by conducting experiments. Stress the safe operating procedures below:

Safe Operating Procedures

• Do not intentionally hurt the worms.
• Be careful when handling the acid rain solution. Wash immediately if it comes in contact with skin/eyes.
• Wear safety glasses at all times.
• Include any additional safety considerations and rules that may be necessary.

The students should know that it would be next to impossible to conduct experiments for every type of atmospheric change, and they should focus on one. Tell the students that they should follow the scientific method, and write up a brief report of their findings. They may use lab notebooks to record their data and write a formal report later if desired.

Summary of Learning:

Assessment

A variety of assessment tools could be used in this inquiry. The following are some examples of possible tools:

• Students should share their results with each other in some way.
  • A class discussion is a great way of sharing data.
  • Ask each group to describe their tests and their findings, and have students from other groups give them positive feedback on their experiments.
• Students could also give a two to three minute presentation of their experiments. Each group could also give their written reports and conclusions to another group. Have the groups try to duplicate their experiments and verify the data.
• Multiple choice questions
  1. To which type of light will planaria mostly be attracted?
     A. UV light
     B. Infrared light
     C. Green light
     D. No light
  2. If an earthworm were to move away from a pool of water contaminated with acid rain, you could conclude that
     A. Earthworms can sense chemicals in their environment
     B. Earthworms don't like water
     C. Earthworms like fresh water
     D. Acid rain would burn through the skin of an Earthworm

Assessment Rubric

Free Response Questions

1. How might you improve your experiment?
   
2. What helped you come to this conclusion?
   
3. Could another group follow your steps and get the same answer?
   
4. How might this test help you to understand relationships of animals to each other, to plants, to the atmosphere?
   
5. What adaptations could help animals deal with the changes in the atmosphere?

Peer Review

Ask students to write-up their procedure and have other classmates try to duplicate their experiments.

Extensions:

• Students could use some of the data that they found to try long term experiments on ecosystems (e.g.,simulate a pond ecosystem and add acid rain to it every week or expose it to UV light).
• Students could test other life forms in controlled experiments using various atmospheric variations, and see if their meat, fruit, waste products, gases etc. contribute to some other atmospheric problems (e.g., Grow bean seedlings that are exposed to UV light and test O2 production rates, or use the same experiment with acid rain and test the acid level of the beans produced).