What was the major contribution of Pasteur and Koch in the field of biology?

• A. Cell Theory
• B. Discovery of microorganisms
• C. Binomial nomenclature
• D. Genetic code

Answer: (B)

The major contribution of Pasteur and Koch in the field of biology was the discovery and understanding of microorganisms and their role in disease. Louis Pasteur is renowned for his work in demonstrating that microorganisms cause fermentation and spoilage, which led to the development of pasteurization and the germ theory of disease. His experiments showed that microbes were responsible for specific diseases, refuting the then-common belief in spontaneous generation.

Robert Koch further advanced this understanding by establishing Koch's postulates, a series of criteria for linking specific pathogens to specific diseases. This laid the groundwork for microbiology as a science. Through their research, both Pasteur and Koch contributed significantly to the field of microbiology, demonstrating that microbes could be isolated and identified as the causative agents of diseases, transforming the understanding of health and disease management.

The options related to cell theory, binomial nomenclature, and the genetic code refer to different aspects and milestones in biology that do not pertain directly to the research and discoveries made by Pasteur and Koch regarding microorganisms and infectious disease.