My Science Box

Summary

Students discover what ecosystems are by exploring the relationships between him/herself, other living things, and the student's environment. Students create and study miniature ecosystems by building a terraqua column - a 2 story soda bottle tower with soil and plants on the top and a water source on the bottom. The terraqua columns will be used throughout the ecology unit for practice with water and soil quality monitoring and with making and recording observations. Later in the unit students can conduct independent investigations with their terraqua columns.

Summary

Students conduct 3 tests of water quality in the classroom that can then be applied to their terraqua columns and to the outdoors: pH, dissolved oxygen, and temperature. They make comparisons between different types of water and draw conclusions about how "healthy" each water source is for fish and other organisms. Through this process, students practice their observational and data analysis skills. Water quality monitoring data is routinely used in the "real world" to determine the effects of habitat restoration, development, pollution, and wastewater treatment. It is often the initial step in describing the health of an ecosystem. There are hundreds of ways to extend this simple activity and make connections to the real world - from monitoring water quality in a local creek to making comparisons between different bodies of water in your area.

Summary

Delve into a micro-habitat that is the size of a drop of water. This lesson allows students to explore the plankton (organisms that drift with the currents) that exist in a drop of pond, lake, or bay water. A microscope is required to view most organisms although some are observable with a hand lens. If possible, this is a fantastic opportunity for students to collect the pond water themselves using pantyhose and a small bottle. If you are pursuing a restoration project, collecting water might be an excellent excuse for an initial visit (as long as the creek/body of water has regions of relative calm where algae can grow on the rocks). Plans for both an initial creek visit activity and a classroom investigation of the water sample are included in this lesson plan. If it is not possible to bring students to the creek or pond, then you can collect the sample ahead of time and skip the creek visit and sense of place activity.

Summary
At the end of the unit, students can now apply their understanding of ecosystems, food webs, resource management, native vs. nonnative species, and human environmental impact to a real world situation. Individuals involved in habitat restoration routinely research and select plants and animals to include in a redesigned ecosystem. In this final project, students will create posters with a minimum of 8 native plants and 5 native animals that should be included in the redesign of the habitat they surveyed previously. They will look at how these organisms will interact and discuss how to sustain the ecosystem into the future. If it is possible to do a long term habitat restoration near your school, this is an excellent exercise to get the students personally invested in the restoration work because they played a role in selecting the species they will reintroduce.

Summary
Once students have some experience working with a basic terraqua column (see the Terraqua Columns Lesson), they have an opportunity to design and conduct their own investigations with their mini-ecosystems. There are hundreds of variables students can manipulate with a minimum of materials – temperature, light, pollution, type of water, type of soil, etc. As a class, students brainstorm variables that might affect the plants, soil, and/or water in a terraqua column. In teams, students propose a project, and once approved, set about testing their ideas and observing the effects of their manipulations on their mini-ecosystem. If your school participates in a local science fair, this is a fantastic activity to introduce students to experimental design, variables, and control groups.

Strawberry DNA: The cloudy substance in the upper layer is strawberry DNA.Summary
What is DNA? What does it look like? In this activity, students extract DNA from strawberries using diluted dish soap and alcohol. Suddenly this mysterious secret of life can be seen materializing out of strawberry juice right in front of students’ eyes. The long tangled DNA strands that ultimately form may be collected using a bamboo skewer or glass stirring rod. The DNA may even be saved in a necklace made from an eppendrof tube, alcohol and string.

Summary
Variation in a population is the raw material on which natural selection works. How do scientists measure and quantify variation in traits? We use garden snails as a model organism in order to describe and measure several different traits. Groups are given a small population of snails and must devise an objective way to measure a trait of their choosing (length, mass, speed, color intensity, stripes, withdrawal reflex reaction time, number of pennies it can carry, etc.). There are many ways to extend this activity. For instance, scientific protocols may be traded between groups, hypotheses may be made concerning what individuals will survive better in different environments, and snails may be tagged and released into one or more environments and the populations monitored over time. A long term open-ended project such as this provides a natural extension and assessment opportunity for both evolution and ecology concepts.

Summary
Inspired by observations of finches on the Galapagos Islands, Charles Darwin came up with an idea that is perhaps the most influential idea in all of science - natural selection. In this classic activity, students learn about natural selection by becoming birds foraging for food on an island (a large area of the schoolyard or classroom). The prey (beans) vary in their coloration such that some blend into the environment better than others. The birds vary in the type of beak they have (plastic forks, spoons and knives). Each season, any prey that survives has a baby bean the same color as the parent. In addition, the most successful birds has a baby with the same beak trait while the least successful birds die (and are reincarnated as the babies of the successful birds). Over several generations, the bird and bean populations shift depending on the environment. Well camouflaged beans survive and reproduce. Birds with beaks that can easily capture beans survive and reproduce. In this way, students model natural selection in 2 species and get a very good idea of how natural selection works.

Summary
Life trapsAs part of recognizing the characteristics of life that all organisms share, students grow microbes on nutrient agar plates. Students swipe surfaces with a sterile Q tip swab and seed plates resulting in a wide range of colorful and prolific bacteria and fungi colonies. Other plates may be simply opened to the air to catch life floating in the air. Through these experiences, students learn that all living things, even those so small and invisible as to be floating in the air, grow and reproduce when provided with the proper nutrients and water. Teachable moments abound since the “dirtiest places”, like the toilet rim, often result in the least bacterial growth while presumably “clean” places, like the surface of your skin, have the most. A fun extension of this activity (see the Going Further section) is to start a sourdough culture from wild yeast in the air and make sourdough bread.