1. Show students the transparency of Master 4.1, Microscopes Across Time. Ask them to look at the pictures of the microscopes and describe the differences they observe.

Write student responses on the board. The pictures present microscopes developed over approximately 250 years. Students can respond to differences in design, such as the development of multiple objective lenses. Some students may respond with differences that are implied, such as better optics, electrical components, and computerized components. The objective of this question is to engage student thinking about the changing face of science and technology across time.

2. Ask the class to imagine that they are scientists or physicians living in the mid-1800s. How much progress do they think they would make solving the problems in Lesson 3?

For example, could they have identified the infectious agent? Could they have determined how the disease was caused? Students will probably have little specific knowledge of when relevant discoveries were made or when relevant technologies were developed. Allow the students to wonder about the timeline of scientific discovery. Even though the problems in Lesson 3 are the same as in any time period, the technologies and knowledge available at a given time will determine the extent to which the problems can be solved.

Content Standard E:
Science often advances with new technologies.

3. Divide the class into three groups.

One group will focus on biology, the second on medicine, and the third on technology.

4. Provide each student in the biology group with one sheet on which a biology development is written. Provide each member of the medicine and technology groups with one sheet on which a development appropriate to their group is written.

In classes with fewer than 24 students, you can give students more than one sheet or you can give the group all eight sheets. In classes with more than 24 students, you can add the following developments:

• biology: covalent bond described (1916, Gilbert Lewis), gene-sequencing methods developed (1977, Walter Gilbert and Allan Maxam, and Fred Sanger and Alan Coulson);
• medicine: first vaccination (1796, Edward Jenner), aspirin introduced (1899, Felix Hoffmann);
• technology: protocol allowing different computer networks to interconnect and communicate with each other (1973, Vinton Cerf and Bob Kahn), automated DNA sequencer introduced (1986, Leroy Hood and colleagues).

Other developments can be added at the teacher’s discretion.

5. Ask students to estimate the year the development on their sheet occurred.
6. Ask students to consult with other group members to place all developments in their category in chronological order.

Allow only a few minutes for students to do this.

7. Have students report their results.

This can be accomplished two ways. Students can call out their results to the teacher, who then records the information along a line drawn on a blank transparency projected for the class to see. Alternatively, students can clip their sheets to the string that spans the width of the room. Sheets should be placed at a location representing the approximate date of each development. For instance, a development occurring in 1850 would be placed midway between 1800 and 1900.

9. Show students a transparency of Master 4.2, Some Key Developments in Biology, Medicine, and Technology, and quickly evaluate how students did at constructing their timeline.
10. Looking at the timeline, ask students what progress they could have made in solving the problems in Lesson 3 if they were working in the mid-1800s.

Students see that technologies available in 1850 were not capable of providing the information required to solve the problems in Lesson 3. Students also develop a firmer understanding of the relationship between technology development and the advancement of knowledge.

1. Ask students if our present technology toolbox is complete. With a show of hands, how many students believe we need new technologies?

You might ask students to suggest some new technologies and write these suggestions on the board. Student responses are less important than shifting the focus from existing technologies to new ones (or refinements of existing ones).

2. Tell students that they will accelerate their journey through time. They are now scientists in the year 2052. Since students know that technologies are generally developed by teams whose members have expertise in more than one discipline, they now will work in teams.
3. Divide the class into groups of four or five. Ask each group to choose one of the following problems:

• development of a technology to detect and measure concentrations of the abnormal protein in affected people from Lesson 3 (that is, a biosensor),
• development of a technology to determine the structure of a protein molecule without having to prepare a crystal of the protein, or
• development of a technology that allows molecules of a drug to be delivered specifically to the protein of affected people from Lesson 3 in a way that allows the physician or scientist to know how much drug is delivered.

Content Standard G:
Scientific explanations must meet certain criteria such as consistency and accuracy.

4. Instruct students to work with their group members to outline the requirements of their technology.

This is a challenging activity for students. However, the key issue is the rationale students provide for their technology. Students should consider at least the following:

• What disciplines are involved in developing the technology?
• Is it a new technology or a refinement of an existing technology?
• What is the level of resolution required?
• How are the issues of scale and probe size dealt with?
• In general terms, how does the technology work?

5. Reconvene the class. Each group in turn should present its technology.

Use class discussion to discover problems and weaknesses and to help group members refine their ideas.

6. As a final means of assessment, ask each student to prepare a written report describing his or her technology.

Technologies should be described in sufficient detail to indicate the student’s understanding of the concepts presented in this module.