STC Second Edition Microworlds Unit In-Service Training Outline Carolina Biological Supply Company

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1 STC Second Edition Microworlds Unit In-Service Training Outline Carolina Biological Supply Company 2700 York Road Burlington NC

2 Microworlds (using the Second Edition Teacher s Guide) NOTE: Unless otherwise specified, all page numbers provided in this outline refer to Section 4, Unit Investigations and Blackline Masters, in the Second Edition Teacher s Guide. Recommended Length for Full Workshop: 4 hrs. Site Requirements: overhead projector, blank overhead transparencies, transparency markers, sink, flat-topped work tables, one 6-ft. or longer table for setup of materials Recommended Work Groups: teams of 2 Recommended Activity Sheets: 1, 2, 5 Recommended Overheads: Fig. 5-3, p. 27; Fig. 7-3, p. 40 Pre-workshop Preparation: obtain Volvox, Blepharisma, and vinegar eel cultures. Purchase a small onion and a newspaper or magazine with color and black-and-white pictures when you arrive at the workshop site. Take a roll of pennies with you. Decide in advance if you or someone at the workshop site will prepare sample hay and grass infusions for lessons This must be done 2-3 weeks in advance in order to have mature infusions. If sample infusions will be available, provide a couple cotton balls in case participants need to slow down any fast-moving microbes. If infusions cannot be set up in advance, another alternative is to demonstrate how the infusions are prepared (see lesson 10 of this outline). You will need to bring a mediumto-large glass jar with lid and some grass (in addition to the bag of hay already in the kit). On-site Preparation: fill and cap the 8 water-dropper bottles. Cut a 3" or larger square of waxed paper for each participant. Set out a square of waxed paper for each participant. Set out a marble, acrylic cube, acrylic sphere, and acrylic cylinder for each team of 2 participants Carolina Biological Supply Company. The STC unit Microworlds was researched and developed by the National Science Resources Center, Washington, DC, and is available exclusively from Carolina Biological Supply Company. This document may be reproduced only by educators in schools and districts in which the Microworlds unit will be taught.

3 Microworlds Workshop Introduction to the unit: 1. Microworlds is an 8-week, 17-lesson unit designed for fifth graders (it also can be used with fourth and sixth graders). Students learn observational skills. Students record their observations. Students investigate magnifiers and magnification. Students learn to use microscopes and related apparatus. Students observe living and nonliving specimens under magnification. 2. Explain icons and their use in curriculum integration. 3. Briefly go over Teaching Strategies (Section 2, Unit Overview, p ). Also review Assessing Students Progress (Section 2, Unit Overview, p. 12) and Student Assessment (Section 5). 4. Briefly explain Materials Management and Safety (Section 3), and Student Notebooks and Writing, Student Reading Resources, and Additional Learning Resources (Sections 6 through 8). The lessons Lesson 1 Observing a Penny You can either let the participants draw circles on a blank sheet of paper or use Activity Sheet 1 for this. 1. Ask them to draw from memory, and in as much detail as possible, the front and back of a Lincoln penny. 2. When drawings are complete, have them take out a penny (distribute pennies from your roll for those who do not have them) and redraw, correcting errors. Discuss mistakes. 3. Give out magnifiers and have them observe with these and redraw. List new details seen under magnification. Background Notes on the Lincoln penny: The Lincoln penny was first issued in On an unworn penny, the initials VDB can be seen with magnification on the bevel at the bottom edge of Lincoln s shoulder. These are the initials of Victor D. Brenner, the artist who did the original design for the front of the Lincoln penny. 2

4 Originally, the penny had a wheat design for the back. In 1959, in commemoration of the 100th anniversary of Lincoln s death, the government issued a new design for the back featuring the Lincoln Memorial. The new back was designed by artist Frank Gasparro, and the initials FG are found at the lower right of the Memorial. Many will be excited to find that the statue of Lincoln can be seen inside the Memorial. 4. Ask, What has this activity taught us about observation? Wait for responses, then ask, Based on this experience, what does observation consist of? Wait for responses. If no one mentions it, point out that they have used an instrument (the magnifier) to improve or enhance their observations. Lesson 2 Communicating Your Observations Note: This lesson can be skipped if you are pushed for time. 1. Participants will need the screen wire, burlap, yarn, and pencil shavings (if available). 2. Have them fill in Activity Sheet When they have completed the sheet, they fold it on the dotted line to hide the objects names and exchange sheets. They then identify the objects from the descriptions and drawings. Lesson 3 Learning about Lenses 1. Ask the teams to place the acrylic shapes and marble over some printed material and observe the optical effects, if any. Write on a blank overhead, Two Characteristics of a Magnifier. Ask, Based on what you discover, give me two characteristics that an object must have to produce magnification. (1. Must be clear; 2. Must be curved.) Do not use answers based on prior knowledge (for example, It has to be convex. ). The answers must not go beyond the actual experience. 2. Distribute the water-dropper bottles and demonstrate placing a drop of water on the waxed paper. Ask them to do the same and observe the drop to see if it has the characteristics of a magnifier. Ask, How could we test to see if the water drop really is a magnifier? (Place the waxed paper over same print.) Let them try it and see that the drop does magnify. 3. Ask them if their magnifier is clear and curved. Point out that this is how science works. Based on observations, etc., scientists make statements that are thought to be true. These statements are tested by being applied to new situations. The tests may confirm the statements, modify them, or disprove them. Lesson 4 Looking through Lenses Skip. 3

5 Lesson 5 Learning to Use the Microscope 1. Introduce the microscope and go over its parts and their uses. Warn participants to never reflect direct sunlight through the lenses when using the microscope. This can cause permanent eye damage. 2. Demonstrate how to place the microfiche on the stage for viewing. Have them pick up microfiche and a microscope and practice using the scope to view the film. Lesson 6 Practicing with the Microscope 1. Have participants cut a portion of a black-and-white photo from a newspaper or magazine. Ask them to observe the picture for patterns and differences in shading. Then have them look at it under a microscope and tell what they see. Ask if they can find a relationship between the dots and the shading of the photo. (In lighter areas the dots are smaller, more widely spaced.) 2. Have participants cut portions of color photographs (faces work especially well) from a newspaper or magazine. They should view these as they did the black-and-white photos. You may wish to talk about four-color printing and/or pointillism in art. Lesson 7 The Field of View (or Seeing More of Less) Note: If you are pushed for time, this lesson can be omitted. 1. Have participants view the screen wire through the 3x (large) magnifier and count the number of holes in the screen (squares) that they can see in one line across the greatest width of the viewing area. Record the number. 2. Have them repeat using the 6x (small) magnifier. 3. Have them repeat using the microscope. They will find that as magnification goes up, the number of squares that they can see goes down. 4. Show an overhead of Fig. 7-3, which shows how the thickness of a hair can be used to estimate size. Then have participants do Activity Sheet 5. Lesson 8 Lesson 9 Preparing Slides, and What Is It? 1. Relatively thin materials (especially those that will dry out) are mounted in water sandwiched between a flat microscope slide and a coverslip. This is called a wet mount. Feathers, hair, or a small piece of newsprint can be used for this. Demonstrate proper slide-making technique. Let the participants make a practice slide. 2. Relatively thick objects are best viewed using a depression slide. Demonstrate the technique (p. 44) and let the participants practice. Poppy seeds, fish scales, sand, grits, and salts work well for this. 4

6 Lesson 10 Exploring Common Objects In this lesson students bring in objects to study, then set up hay and grass infusions (in preparation for lessons 15 and 16). If sample infusions were prepared in advance of the workshop, talk through or demonstrate how to set up an infusion by following the directions on p If sample infusions were not prepared, then postpone this discussion until lessons in the workshop. Lesson 11 Looking Inside an Onion Quarter a small onion and show how the layers can be separated. Demonstrate how to pull the skin from the inner (concave) surface of a layer and prepare a slide. Participants should make a slide and view the onion cells. Lesson 12 Lesson 13 Lesson 14 Looking at Living Things: Volvox Looking at Living Things: Blepharisma, and Looking at Living Things: Vinegar Eels In these lessons, participants will make and examine slides of three very different microorganisms: Volvox, Blepharisma, and vinegar eels. To avoid confusion, it is best to finish using one culture before presenting the next. As you bring out each culture, refer to the appropriate Background for that organism (Volvox p. 67, Blepharisma p. 71, and vinegar eels p. 75). Due to their small size, Blepharisma can be hard to find. They tend to congregate in and around the debris in the bottom of the culture. For this reason, do not stir the culture. Lesson 15 Lesson 16 Looking at Living Things: Hay and Grass Infusions I, and Looking at Living Things: Hay and Grass Infusions II These activities are the most interesting in the unit. If you prepared hay and grass infusions two to three weeks before the workshop, have participants prepare slides and observe any microbes they find. If mature infusions are not available, the two lessons will have to be a talk-through. You can demonstrate how to set up a hay and grass infusion by following the directions on p These activities are highly recommended. Lesson 17 Post-Unit Assessment Participants revisit their activities from lesson 1 to determine what they ve learned about observation and magnification. 5

7 Wrap-up 1. Give out any evaluation forms and ask that they be completed. 2. Ask for help in cleanup. 3. Be available for questions/discussion. 6