Biological and medical scientists using this technology manipulate the genetic material of animals or plants, attempting to make organisms more productive or disease resistant. The first application of this technology has been in the medical and pharmaceutical areas. Advances in biotechnology have opened up research opportunities in almost all areas of biology, including commercial applications in agriculture and the food and chemical industries. Most biological scientists who come under the broad category of biologist are further classified by the type of organism they study or by the specific activity they perform, although recent advances in the understanding of basic life processes at the molecular and cellular level have blurred some traditional classifications. Aquatic biologists study plants and animals living in water.
Marine biologists study salt water organisms and limnologists study fresh water organisms.
Marine biologists are sometimes called oceanographers, but oceanography usually refers to the study of the physical characteristics of oceans and the ocean floor. Biochemists study the chemical composition of living things. They try to understand the complex chemical combinations and reactions involved in metabolism, reproduction, growth, and heredity. Much of the work in biotechnology is done by biochemists and molecular biologists because this technology involves understanding the complex chemistry of life. Botanists study plants and their environment.