Introduction

Plants, animals, fungi, protozoa, algae, bacteria, and viruses all inhabit the natural world. Biology is the study of these and other living things. Today's constantly advancing technology allows researchers to investigate nature's tiniest living organisms; this field of study is known as microbiology.

In this volume you will learn about many of the branches of biology. The sheer volume of scientific information available can be mind-boggling, but areas of specialization allow scientists to focus on certain areas, like animals (zoology) or plants (botany). Some biologists study even more specific areas, such as insects (entomology) or bacteria (bacteriology). You will also learn about the history of biology. The early Greeks were the first to formally study the natural world. During the Renaissance, Leonardo da Vinci linked human anatomy to that of animals. Swedish biologist Carolus Linnaeus devised the modern method of classifying organisms, known as taxonomy.

The development of the microscope has been and continues to be a huge scientific advancement. Scientists began to develop microscopes as early as the 1600s.

This powerful tool allowed them to study all kinds of previously unknown processes and structures, including the cell. Modern microscopes, in particular electron microscopes, have helped scientists unravel the mysteries of DNA.

Areas of microbiology you will read about include bacteriology, protozoology (the study of protozoans), phycology (algae), mycology (fungi), virology (viruses), and exobiology (life outside Earth). Some microbiologists have made great strides with pure cultures

(cultures containing the growth of a single kind of organism free from other organisms) and methods of cultivating and identifying microbes. You will also learn about the very unit that interests so many scientists: the cell. Some organisms, such as yeasts, are singlecelled, but others, such as humans, are composed of many billions of cells. Simple cells only have a few parts, but more complex cells have a variety of parts with many functions. Finally, you will learn about the rich history of cell theory. Robert Hooke first coined the term “cell” in the 1600s.