Connect content-area literacy and science with differentiated readers featuring lab activities and profiles of related scientitists
Have you ever seen a cell? Cells are the smallest unit of life. They are called the building blocks of life. We cannot see individual cells with our naked eyes.
We must use a microscope to see them. The importance of cells is outlined in the Cell Theory. Three scientists developed the Cell Theory in the 1800s. They were Matthias Schleiden (mah-TEE-ahs SHLAHYD-n), Rudolf Virchow (ROO-dawlf FIR-koh), and Theodor Schwann (TEY-oh-dawr shvahn). The Cell Theory has three parts. First, all living things are made of one or more cells. Second, cells are the basic unit of life of all living things. Third, all cells come from other cells.
In many ways, plant and animal cells are similar. But there are also differences. For example, plant and animal cells have different structures. You will learn about them.