The document introduces the cell as the smallest unit of life. It discusses how Robert Hooke first observed cells under a microscope in 1665 and named them. The Cell Theory states that all living things are made of cells, cells are the basic functional units of life, and cells only come from preexisting cells. Cells come in different shapes and sizes depending on their function, and all cells contain internal structures called organelles that perform specific functions, surrounded by a cell membrane with the nucleus containing genetic information at the center.

1. INTRODUCTION TO THE CELL