Life may be studied at various levels - molecular, cellular, organismal, population, community or ecosystem. Some bioscientists are parts of multidisciplinary teams that tackle several aspects of the same problem. Ultimately, however, it is the nature and scope of the research problem that determines which techniques and research strategies are appropriate. New subdisciplines in biology will surely emerge as a consequence of rapidly changing technology and the appearance of new global health and environmental problems. Modern biology is integrative in the sense that a biological question may be studied from different fields as diverse as biochemistry and behavior, and from different vantage points ranging from molecules to whole organisms and even ecosystems.
Many biologists use a comparative approach, comparing structures, organisms, ecosystems, etc.
This is necessary to understand biodiversity and evolutionary change. The upper-level biology courses taken by biology majors depend upon their degree requirements, courses available and the student's own area of interest. Some biologists prefer to become broadly trained at the undergraduate level and some prefer to specialize immediately. This usually determines the biology courses a student elects to take. Selecting a career that matches your personal goals and talents requires that you have enough background information to make an informed choice.