As a cell developmental biologist, I hope your students become fascinated by how cells become specialized and how they work. Cells can be very interesting to students, once they jump past the size issue. Microscopes can help to make cells seem tangible, although most of the activities in this unit are designed to teach without the use of any equipment. One disadvantage of thinking of cells only as they appear in a microscope is that typically those cells are dead. Living cells are much more interesting, since they can move, crawl, and some cells, such as nerve cells with their spectacular axons, can send out long processes.
As you know, cells are the units of human life. Without cells there would be no life. Each of us originated from a single cell. One of the first activities that students experience investigates the questions, “What would it be like if we were made up of a single cell?” and “Why is it necessary to have millions of tiny cells to build a human?”
Your students can probably already name important cell types from other parts of the curriculum, such as nerve cells, heart muscle cells, sperm, and eggs. They know humans develop from a single cell. Their curiosity can be reawakened to focus on questions such as those that follow. How can one cell, the fertilized egg, lead to such different kinds of cells in bone, in blood, and in the lens of an eye? How do these cells become specialized? How does cellular diversity happen?
The activities in this unit are more important than the text. You know your own students and can anticipate which of the various activities will be best for them. Some are fun and others are more challenging. There is a broad range of activities. Thus each student should find some aspect of cells that is enjoyable and stimulating to investigate.
This unit has five sections, so you may want to select the material that best meets the needs of your class. Some students may want to investigate the artistic side of cells. For example, you may choose to use the Mini Activity in which soap bubbles represent cells. Other students may want to take a mathematical approach to investigating cells. For them, activities that deal with surface area and volume of cells, such as Activity 1-1, may be most interesting.
Teaching from specific questions about cells is a great way to approach this unit. I hope that you and your students will come up with questions that this unit does not answer. I hope you will ask students to keep a journal of their questions about cells. As they go through middle school, high school, and college, there will be new answers for many of these questions. One good question often leads to others. Someday they may actually be involved in finding answers to some questions.