Biology is the branch of science dealing with the study of life. Below is a brief overview about subject of biology and the many disciplines that make it comprises.

  1. Biology is concerned with the characteristics, classification, and behaviors of organisms, how species come into existence, and the interactions they have with each other and with the environment.
  2. Biology encompasses a broad spectrum of academic fields that are often viewed as independent disciplines. However, together they address phenomena related to living organisms (biological phenomena) over a wide range of scales, from biochemistry to ecology.
  3. All concepts in biology are subject to the same laws that other branches of science obey, such as the laws of thermodynamics and conservation of mass.
  4. At the organism level, biology has explained phenomena such as birth, growth, aging, death and decay of living organisms, similarities between offspring and their parents (heredity) and flowering of plants which have puzzled humanity throughout history.
  5. Other phenomena, such as lactation, metamorphosis, egg-hatching, healing, and tropism have been addressed.
  6. On a wider scale of time and space, biologists have studied domestication of animals and plants, the wide variety of living organisms (biodiversity), changes in living organisms over time (evolution), extinction, speciation, social behavior among animals, etc.
  7. While botany encompasses the study of plants, zoology is the branch of science that is concerned about the study of animals and anthropology is the branch of biology to study human beings.
  8. However, at the molecular scale, life is studied in the disciplines of molecular biology, biochemistry, and molecular genetics.
  9. At the next level, that of the cell, it is studied in cell biology.
  10. At the multicellular scale, it is examined in physiology, anatomy, and histology.
  11. Developmental biology studies life at the level of an individual organism's development or ontogeny.
  12. Moving up the scale towards more than one organism, genetics considers how heredity works between parent and offspring.
  13. Ethology considers the behavior of groups of organisms.
  14. Population genetics looks at the level of an entire population, and systematic considers the multi-species scale of lineages.
  15. Interdependent populations and their habitats are examined in ecology and evolutionary biology.
  16. A speculative new field is astrobiology (or xenobiology), which examines the possibility of life beyond the Earth.