Intro to Cells and Cellular Unity

Apuntes

ESSENTIAL CELL BIOLOGY CHAPTER ONE 2 CHAPTER 1 Cells: The Fundamental Units of Life In this chapter, we introduce the concept of cells: what they are, where they come from, and how we have learned so much about them. We begin by looking at the great variety of forms that cells can adopt, and we take a preliminary glimpse at the chemical machinery that all cells have in common. We then consider how cells are made visible under the microscope and what we see when we peer inside them. Finally, we discuss how we can exploit the similarities of living things to achieve a coherent understanding of all forms of life on Earth—from the tiniest bacterium to the mightiest oak. UNITY AND DIVERSITY OF CELLS Biologists estimate that there may be up to 100 million distinct species of living things on our planet—organisms as different as a dolphin and a rose or a bacterium and a butterfly. Cells, too, differ vastly in form and function. Animal cells differ from those in a plant, and even cells within a single multicellular organism can differ wildly in appearance and activity. Yet despite these differences, all cells share a fundamental chemistry and other common features. In this section, we t...