Biology: Definition of Biology, History of Biology, Divisions of Biology (For CBSE, ICSE, IAS, NET, NRA 2022)

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Definition of Biology

  • It can be defined as the study of living organisms, their origins, anatomy, morphology, physiology, behaviour, and distribution. ″
  • In simple words, we can say the natural science that studies life and living organisms.

History of Biology

The term Biology was introduced through the works of Michael Christoph Hanow in 1766.

Introduced independently four more times through:

  • Thomas Beddoes (1799)
  • Karl Friedrich Burdach (1800)
  • Gottfried Reinhold Treviranus (1802)
  • Jean-Baptiste Lamarck (1802)

A host of discoveries and technological innovations came during the 19th century.

Field of study:

  • Traditions of medicine
  • Collective knowledge from physicians
  • Works of prominent historical figures

Divisions of Biology

Divisions of Biology

Foundations of Modern Biology

Foundations of Modern Biology

Cell Theory

  • It states that the cell is the fundamental unit of life.
  • All living things are composed of one or more cells.
  • All cells arise from pre-existing cells through cell division.


  • According to this theory, all organisms on the Earth, both living and extinct, have descended from a common ancestor.
  • The term “evolution” was introduced into the scientific lexicon by Jean-Baptiste de Lamarck in 1809.
  • Evolution is central to all fields of biology.


  • In all organisms, genes are the primary units of inheritance.
  • A gene is a unit of heredity and corresponds to a region of DNA.
  • Cells transcribe a DNA gene into an RNA version of the gene.


  • It is the ability of an open system to regulate its internal environment.
  • Maintains stable conditions by means of multiple dynamic equilibrium adjustments that are controlled by interrelated regulation mechanisms.
  • Homeostasis is exhibited by all living organisms, whether unicellular or multicellular.

Energy and Human Life

Energy and Human Life

Hierarchy of Biological Classification

Hierarchy of Biological Classification


Q 1. What are the eight parts into which Biology can be divided?

Answer: The eight parts of division are namely Botany, Zoology, Anatomy, Physiology, Ecology, Immunology, Genetics, and Microbiology.

Q 2. What is the simple definition of Biology?

Answer: Biology can be defined as the study of living organisms, their origins, anatomy, morphology, physiology, behaviour, and distribution. ″