In this unit, students investigate both living and nonliving specimens with a variety of magnifiers, including the microscope. Their experiences introduce them to the following concepts, skills, and attitudes.

Concepts

• In order to magnify, a lens must be transparent and curved.
• Magnification is directly related to how much a lens is curved.
• Higher magnification reveals more detail in a smaller area of a specimen being observed.
• In light microscopes, lenses are combined to focus light and increase magnification.
• Scientists designed and used early microscopes to extend their observational ability and to investigate their ideas.
• Some living organisms are too small to see without magnification.
• All living things are made of at least one cell.
• When magnified, all cells have observable structures.
• Microorganisms are widespread in nature.
• Bacteria are partly responsible for the decomposition of organic material over time.
• Some bacteria are eaten by other microorganisms.
• Like all organisms, microorganisms grow and reproduce.
• Microorganisms have structures that help them survive in specific environmental conditions.
• Changing environmental conditions promote the survival of some microorganisms over others and therefore change microbial communities.

Skills

• Determining which of various objects can magnify.
• Using magnifiers, including hand lenses and microscopes, to observe living and nonliving specimens.
• Using appropriate equipment and techniques to prepare microscope slides for viewing.
• Using a microscope to observe basic cell structure.
• Communicating detailed observations through writing, drawing, and discussion.
• Making measurements of small objects using hair-widths and millimeters.
• Exploring ways to slow the movement of living microscopic specimens for closer observation.

Attitudes

• Developing an interest in exploring microscopic specimens.
• Recognizing that microorganisms have many of the same needs as other living things.
• Developing an awareness of the diversity and complexity of microbial life.
• Developing an awareness of the interactions among living things and between living things and their environment.