what is Biology ? Branches of Biology

Biology is the word, which is derived from the greek words bios meaning life and logos meaning study. It is defined as the science of life and living organisms. An organism is a living entity consisting of one cell e.g. bacteria, or several cells e.g. animals, plants.


Biology is the natural science, that is the studies of life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development and evolution. It recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis.

Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: theoretical biology uses mathematical methods to formulate quantitative models while experimental biology performs empirical experiments to test the validity of proposed theories and understand the mechanisms underlying life and how it appeared and evolved from non-living matter about 4 billion years ago through a gradual increase in the complexity of the system.

Branches of Biology

It can be divided into separate branches for convenience of study, though all the subdivisions are interrelated by basic principles.

  1. Astrobiology – the study of evolution, distribution, and future of life in the universe
  2. Biochemistry – the study of the chemical reactions required for life to exist and function, usually a focus on the cellular level
  3. Biological engineering – the attempt to create products inspired by biological systems or to modify and interact with the biological systems
  4. Biogeography – the study of the distribution of species spatially and temporally
  5. Bioinformatics – the use of information technology for the study, collection, and storage of genomic and other biological data
  6. Biomechanics – the study of the mechanics of living beings
  7. Biomedical research – the study of health and disease
  8. Biophysics – the study of biological processes by applying the theories and methods traditionally employed in the physical sciences
  9. Biotechnology – the study of the manipulation of living matter, including genetic modification and synthetic
  10. Cell biology – the study of the cell as a complete unit, and the molecular and chemical interactions that occur within a living cell
  11. Chronobiology – the study of periodic events in living systems
  12. Cognitive biology – the study of cognition
  13. Conservation biology – the study of the preservation, protection, or restoration of the natural environment, natural ecosystems, vegetation, and wildlife
  14. Cryobiology – the study of the effects of lower than normally preferred temperatures on living beings
  15. Developmental biology – the study of the processes through which an organism forms, from zygote to full structure
  16. Ecology – the study of the interactions of living organisms with one another and with the non-living elements of their environment
  17. Evolutionary biology – the study of the origin and descent of species over time
  18. Genetics – the study of genes and heredity
  19. Immunology – the study of the immune system
  20. Marine biology (or biological oceanography) – the study of ocean ecosystems, plants, animals, and other living beings
  21. Microbiology – the study of microscopic organisms (microorganisms) and their interactions with other living things
  22. Molecular biology – the study of biology and biological functions at the molecular level, some cross over with biochemistry
  23. Nanobiology – the application of nanotechnology in biological research, and the study of living organisms and parts on the nanoscale level of organization
  24. Neuroscience – the study of the nervous system
  25. Paleontology – the study of fossils and sometimes geographic evidence of prehistoric life
  26. Pathobiology or pathology – the study of diseases, and the causes, processes, nature, and development of disease
  27. Pharmacology – the study of the interactions between drugs and organisms
  28. Physiology – the study of the functions and mechanisms occurring in living organisms
  29. Phytopathology – the study of plant diseases (also called Plant Pathology)
  30. Psychobiology – the application of methods traditionally used in biology to study human and non-human animals behaviour.