• conducting investigations
• gathering, organizing, and representing data
• formulating conclusions from investigational data
• applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

12 C LS 6: The behavior of organisms: Grades 9-12
6.2 Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism’s own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.

12 A SI 1: Abilities necessary to do scientific inquiry: Grades 9-12
1.2 Design and conduct scientific investigations. Designing and conducting a scientific investigation requires introduction to the major concepts in the area being investigated, proper equipment, safety precautions, assistance with methodological problems, recommendations for use of technologies, clarification of ideas that guide the inquiry, and scientific knowledge obtained from sources other than the actual investigation. The investigation may also require student clarification of the question, method, controls, and variables; student organization and display of data; student revision of methods and explanations; and a public presentation of the results with a critical response from peers. Regardless of the scientific investigation performed, students must use evidence, apply logic, and construct an argument for their proposed explanations.

1.4 Formulate and revise scientific explanations and models using logic and evidence. Student inquiries should culminate in formulating an explanation or model. Models should be physical, conceptual, and mathematical. In the process of answering the questions, the students should engage in discussions and arguments that result in the revision of their explanations. These discussions should be based on scientific knowledge, the use of logic, and evidence from their investigation.

1.5 Recognize and analyze alternative explanations and models. This aspect of the standard emphasizes the critical abilities of analyzing an argument by reviewing current scientific understanding, weighing the evidence, and examining the logic so as to decide which explanations and models are best. In other words, although there may be several plausible explanations, they do not all have equal weight. Students should be able to use scientific criteria to find the preferred explanations.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

General Instructions to the Teacher:

This task is designed to take students approximately 30 minutes to complete.

Students will be working individually during this exercise.

Students should be ready to work as soon as the period begins. The materials should be set out at each lab station, if possible. A central supply area, if needed, should be easily accessible. All supplies should be clearly labeled.

Materials for "Sow Bug Habitats":

At each station students should have:

• beaker of water
• scissors
• eyedropper
• clock/timer
• 1 extra petri dish lid
• stack of paper towels
• masking tape
• 1 sheet black construction paper
• a petri dish with 10 sow bugs

Advance Preparation:

Sow bugs/Pill bugs are scavengers which are easy to culture. You can order a kit from various science supply houses. Another option is to establish your own culture. These animals can be easily found under rocks and rotting logs. A plastic shoe box with holes melted in the lid with a hot dissecting needle will serve as a container. Place several centimeters of soil in the bottom of the box. The soil should be from a wooded area with much organic matter. There should be wood chips, leaves, and stones. Be certain to keep the soil moist since sow bugs are crustaceans and use gills to breathe. Sprinkle a little oatmeal on the surface of the soil and add some potato slices and a few lettuce leaves or carrot peels. Place your culture where it won't be disturbed being certain to keep it moist and to periodically add vegetable scraps.

Sow bugs can be placed into petri dished a day or two ahead of time only if the sow bugs are provided with a source of moisture. A wet piece of paper towel can be used. Remove prior to the start of the experiment by the teacher. To remove sow bugs from the paper towel, gently shake or move them with forcepts or small paint brush. At the end of the experiment, return wet paper towel to petri dishes. Approximate time to set up 10 petri dishes with 10 sow bugs in each: 20-30 minutes.

Safety:

• Be careful.
• Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.

Extensions/Modifications:

None