Biology subfields are many and varied and include microbiology, anatomy, morphology, plant and animal physiology, ecology, pathology, cell biology, molecular biology, marine biology, and genetics, just to name a few. There are fields of specialization for different classifications of living things: herpetology, entomology, and ornithology, for example. For all these areas, the elements of the job are essentially the same: building on the work of others, both past and present, through experimentation and observation.

Most research in biology uses a collaborative approach. Team members review previous research and experiments, and then set a goal for their project. They may form a hypothesis (an educated guess) to prove or disprove a current theory or set an open-ended objective, such as finding out what happens over time to people who smoke or drink. An experiment may prove something or not. After experimentation, the biologist analyzes the results, often publishing his or her findings in a scientific journal article. Publishing results is a key part of doing research, for only by sharing data and evaluations can the scientific community make the most of research. Scientists working under contracts with research companies do not own their discoveries; their research becomes the property of the employer. Scientists working independently can keep their discoveries as their own and have the right to patent and charge others for using their research.

Generally, those working in the biology field do one of four types of work: basic research, applied research, testing, or support. Basic research seeks knowledge for its own sake, uncovering fundamental truths and transforming the unknown into the known. Often done at universities, basic research includes all areas of biology. Applied research deals with translating basic knowledge into practical, useful products and processes for use in areas such as medicine or agriculture.

Research biologists at universities generally split their time between their research projects and teaching. Because researchers need skilled help from others trained in biology, some biologists work in support roles, such as laboratory technicians, who help carry out experiments. All specialists must combine a thorough knowledge of general biology with other technical skills and professional training.

Research biologists work for government agencies in the areas of conservation, environmental protection, agriculture, and the use of natural resources. They work for private industry in the development of new tools, devices, and drugs for medical diagnosis and treatment. Research biologists also study genetics, including human, plant, and animal genetics, with hopes of finding applications in medicine and agriculture.

It is now fairly common for people to have jobs that combine their knowledge of biology with other specialized training. The office for many of these jobs is the outdoors and the dress is casual. Horticulturists, for example, work in greenhouses and fields, developing new crop varieties and designing landscape plans. Zookeepers and zoologists may work with captive breeding programs for endangered species. Zoos, museums, and nature centers hire educators, exhibit designers, artists, and other specialists with biology backgrounds. Those with a talent for writing may work as science journalists, breaking down science so that nonexperts can understand it. Other biologists work as policy analysts for the government, helping to develop science-based legislation. Physicians, dentists, nurses, medical technicians, and physician assistants must also have solid biology backgrounds.