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 combinations and reactions involved in metabolism, reproduction, growth, and heredity. Much of the work in biotechnology is done by biochemists because this technology involves understanding the complex chemistry of life.
Botanists study plants and their environment.
Some study all aspects of plant life. While others specialize in areas such as identification and classification of plants, the structure and function of plant parts, the biochemistry of plant processes, or the causes and cures of plant diseases. Microbiologists investigate the growth and characteristics of microscope organisms such as bacteria, viruses, and fungi. Medical biologists study the relationship between organisms and disease or the effect of antibiotics on microorganisms. Many microbiologists are using biotechnology to advance knowledge of cell reproduction and human disease.