Pre-Lab: Using a Microscope to Estimate Size
Problem How can you use a microscope to estimate the size of an object?
Materials compound microscope, transparent 15-cm plastic ruler, prepared slide of plant root or stem, prepared slide of bacteria
Lab Manual Chapter 1 Lab
Skills Focus Observe, Measure, Calculate, Predict
Connect to the Science provides a way of knowing the world. The use of technology to gather data is a central part of modern science. In biology, the compound microscope is a vital tool. With a microscope, you can observe objects that are too tiny to see with the unaided eye. These objects include cells, which are the basis for all life.
In this lab, you will explore another important use of the microscope. You will use the microscope to estimate the size of cells.
Explain How did the invention of the microscope help scientists know the natural world?
Explain How can a microscope help a scientist use scientific methodology?
Infer List one important fact about life that scientists would not know without microscopes. Hint: Review the characteristics of living things.
Preview the procedure in the lab manual.
Review Which lens provides more magnification—a low-power lens or a high-power lens? Which lens provides the larger field of view?
Use Analogies A photographer may take wide views and close-ups of the same scene. How are these views similar to the low-power and high-power lenses on a microscope? What is an advantage of each view?
Calculate Eight cells fit across a field of view of 160 µm. What is the width of each cell?
Predict Which cell do you think will be larger, the plant cell or the bacterial cell? Give a reason for your answer.
Visit Chapter 1 online to test yourself on chapter content and to find activities to help you learn.
Untamed Science Video
Be prepared for some surprise answers as the Untamed Science crew hit the streets to ask people basic questions about science and biology.
Art in Motion
Learn about the steps scientists use to solve problems. Change the variables, and watch what happens!
Art Review
Review your understanding of the various steps of experimental processes.
InterActive Art
Design your own experiment to test Redi's and Pasteur's spontaneous generation experiments.
Data Analysis
Investigate the different strategies scientists use for measurement.