Engineering combines quantitative analysis and synthesis to elucidate system design principles. Through the genomics revolution engineers can now begin to tackle biological problems using the same “measure, model, and manipulate” approach they have applied to physics and chemistry. Indeed, applying this system approach is widely recognised as essential not only for the development of innovative biotechnologies but also to yield fundamental scientific understanding of biological systems.
As our ability to modify and control biological systems increases, biological processes will replace chemical and mechanical processes due to their inherent advantages of renewable resources, mild operation conditions and minimal waste problems. Early signs of the change are seen not only in the high-value pharmaceutical industry, but also in the production of bulk chemicals like lysine by fermentation and in bioleaching of copper and gold from mineral ore.
Advances in our understanding of and ability to mimic biological systems are also inspiring completely new approaches such as nanotechnology and tissue engineering, which will form the foundation of new industries of the 21st century. Chemical biology is a scientific discipline spanning the fields of chemistry and biology. It involves the application of chemical techniques and tools, often compounds produced through synthetic chemistry, to the study and manipulation of biological systems. Chemical biologists attempt to use chemical principles to modulate systems to either investigate the underlying biology or create new function.
Research done by chemical biologists is often closer related to that of cell biology than biochemistry. Biochemists study of the chemistry of biomolecules and regulation of biochemical pathways within cells and tissues, e. g. cAMP or cGMP, while chemical biologists deal with novel chemical compounds applied to biology. Pharmacology researches the effect of highly selective chemical compounds on cells, tissues, organs and organisms. Toxicology researches the adverse effect of highly selective chemical compounds on cells, tissues, organs and organisms.
In the field of drug discovery, hit identification is the screening of chemical libraries of small molecules in biological systems such ascell lines or whole animals to identify compounds that cause a desirable change in phenotype. 
This strategy which employsphenotypic screening to identify starting points for drug discovery is also known as classical pharmacology, forward pharmacology,or phenotypic drug discovery (PDD).  In ecology, you study the relationships among organisms. You look at past, present, and future environments. You examine factors such as population size, pollutants, rainfall, temperature, and altitude.
You study various environments – oceans, deserts, forests, and grasslands – and the dynamics of each habitat. You learn about plants, animals, birds, fish, and humans. You also learn about natural predators and how species compete for food, water, and shelter. This program requires a broad background in the life and natural sciences.
The study of ecology enables you to contribute to our understanding and preservation of the natural world. Some community colleges offer a two-year program in this field. With this preparation, you can work as a field crewmember, technical assistant, or lab technician.
Pharmacology (from Greek ????????, pharmakon, “poison” in classic Greek; “drug” in modern Greek; and -????? , -logia “study of”, “knowledge of”) is the branch of medicine andbiology concerned with the study of drug action, where a drug can be broadly defined as any man-made, natural, or endogenous (within the body) molecule which exerts a biochemical and/or physiological effect on the cell, tissue, organ, or organism.
More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinalproperties, they are considered pharmaceuticals.
Astronomy The natural world beyond the earth Astrophysics All physics required to understand astronomical phenomena (includes elements of nearly all fields of physics) Cosmology The universe: its origin, structure, and evolution on the largest possible scale Cosmogony The origin of the universe (and sometimes the solar system), is a subfield of cosmology Astrochemistry All chemistry required to understand astronomical phenomena (primarily the chemistry of the interstellar medium and protostellar accretion disks).
Space Science The physics of the interplanetary medium Planetary Science The physics of planets, their formation, structure and evolution Astrology The purported relationships between the planetary positions at the time of a person’s birth, that person’s personality, and events in that person’s life. A pseudoscience, has no scientific basis.