The term "biology" is derived from the Greek words "bios," meaning life, and "logos," meaning study or science. Biology is defined as the study of living organisms, their origins, anatomy, morphology, physiology, behaviours, distribution, and evolution. Aristotle is known as the father of biology. According to the International Union for Conservation of Nature (IUCN), approximately 8.7 million species exist on Earth, but only 1.2 million have been scientifically described and cataloged. Biology is a broad and diverse field that encompasses many subdisciplines, including molecular biology, cell biology, anatomy and physiology, animal behavior, population biology, ecology, systematics, microbiology, virology, botany, and zoology and deals with all the physicochemical aspects of life. This article explains the definition of biology, branches of biology, important concepts, history of biology, and examples.
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So, biology is a science concerned with studying life and living things including how they interact with the environment and other organisms. The origin, structure, function, evolution, development, distribution, and classification of all living things are studied under biology. It also explains the cellular and bacterial forms of life. New technology has helped us understand more about living things. For example, when scientists discovered viruses, it made them think about what it means to be alive. Modern biology explains the more complex forms and systems that support life. Biology is a constantly changing science; new developments, including genetic engineering and synthetic biology- change our notions of what life is and will be.
Class 11 biology mostly focuses on foundational concepts such as cell biology, whereas class 12 biology includes advanced topics related to genetics and evolution. Biology is important for Central Board of Secondary Education (CBSE) exams of classes 6 to 12 and several competitive exams, such as National Eligibility cum Entrance Test (NEET-UG), AIIMS BSc Nursing.
The study of biology includes several branches of biology that embrace different dimensions of life and often relate to other scientific streams. For example, Synthetic Biology applies knowledge of Biology to engineering principles to design and construct new biological parts, devices, and systems.
Similarly, Systematic Biology focuses on complex interactions within biological systems. Using both computational and experimental approaches, it explains how networks of genes, proteins, and other cellular components interact to perform functions with each other.
Some of the other important divisions within biology studies are:
The entire study of biology, therefore, has been divided into several divisions of biology to study the details of specific aspects of life. Some of the branches of biology have further combined with other subjects like chemistry and physics and resulted in the discovery of new fields of study.
Key divisions of biology include:
Anatomy is the branch of biology that deals with the study of structure and organisation in living organisms. It includes the study of humans, plants, and animals concerning the internal and external features related to other body parts or systems.
Molecular Biology deals with the molecular basis of biological activity. It describes in detail DNA, RNA, and proteins, and how these molecules regulate cell functions.
The study of heredity and variation is known as genetics. It explains how traits are inherited from one generation to another through genes. The two important fields of genetics are classical genetics, dealing with Mendelian inheritance; and molecular genetics, studying genes at the DNA level.
This branch applies biological systems and organisms to develop or alter products for use by humans. Examples of such recent biotechnology inventions include genetic engineering, cloning, and the use of CRISPR technology.
Microbiology is the study of microorganisms, including bacteria, viruses, and fungi. The discipline is important in understanding diseases, antibiotics, and microbes' ecological roles.
The course of zoology covers the study of animal behaviour, physiology, and classification. Subjects ranging from minute insects to large mammals are taken up for study by zoologists.
Botany deals with life in plants that is growth, reproduction, metabolism, and disease. For life to exist on Earth, it needs plants to provide oxygen, food, and a habitat.
Ecology deals with the study of the relationship between living organisms and their environment, that is ecosystems, biodiversity, and conservation.
Immunology deals with the study of the immune system, mainly how the body protects itself from the pathogenic attacks of viruses and bacteria. It includes the mechanism of immune responses and the role of antibodies in protecting the body from infections. This topic is extensively covered in class 12 biology.
It studies the functioning of living organisms and their systems, and how organs, tissues, and cells work together to provide life. It includes processes like respiration, blood circulation, and digestion, which regulate body functions and its response to the environment. This topic is included in the syllabus of Biology class 12.
The "biology" definition explains living organisms and biology examples show how these organisms grow, work and interact with their environment:
Below are the most important and basic concepts of biology. These concepts are included in the biology ncert and students can also get biology notes easily on these concepts:
Carbon is a very versatile element, it makes the basic framework of organic molecules. Due to the special properties of its electronic structure, carbon can exist in all three important types of chain bonds-simple, double, and triple-along with rings and complex ring systems that are necessary for living systems. |
Human biology studies the structure, function, and processes of the human body. The circulatory, respiratory, and nervous systems along with many other systems keep the individual healthy and in homeostasis. |
Large biological molecules are defined as macromolecules. Examples include proteins, carbohydrates, lipids, and nucleic acids. They are highly important molecules for cell structure, storage of energy, and passage of genetic information. |
The energy within living systems is largely derived from chemical reactions. The substances that accelerate chemical reactions are known as catalysts and, in living organisms, enzymes. Enzymes would lower the activation energy for all sorts of life processes, which include metabolism and digestion. |
A cell is the smallest unit of life. Organelles which constitute the cell include the nucleus, mitochondria, and endoplasmic reticulum. These organelles interact in carrying out vital functions of the cell that include energy production, synthesis of proteins, and waste removal, among others. Cell Biology topic is covered in class 11 biology. |
Cell membranes are formed by lipid bilayers that regulate the movement of substances in and out of the cell. The internal environment of the cell is regulated by various transport mechanisms across the membrane, including diffusion, osmosis, and active transport. |
Cellular respiration is the process through which cells use glucose and oxygen to form ATP, the energy currency of the cell. It involves changes in glycolysis, the Krebs cycle, and the electron transport chain, releasing energy to fuel cellular activities. |
Light energy is transformed into chemical energy by photosynthesis in plants, algae, and some bacteria, producing glucose and oxygen. It occurs in the chloroplasts and is of immense importance regarding the flow of energy within ecosystems. |
Cell division involves mitosis and meiosis, processes in which cells form other cells. Mitosis produces genetically identical cells for growth and repair, while meiosis generates genetically diverse gametes for sexual reproduction. |
Classical genetics studies the study of inheritance patterns. This is mainly based on Mendel's laws. Molecular genetics involves the study of genes at a molecular level that includes a great emphasis on DNA, RNA, and the synthesis of proteins. |
DNA stands for deoxyribonucleic acid. It is the very molecule that contains genetic information stored in living organisms. DNA dictates cellular processes by coding for proteins and, upon its replication, ensures that genetic information is passed on to offspring. |
The central dogma of molecular biology is the movement of genetic material from DNA to RNA to protein. It gives information about how DNA transcribes mRNA by translating into proteins that carry on different cellular functions. |
Gene regulation is a control function that allows the cells to express genes properly at required times and in adequate amounts, ensuring the proper production of proteins. It is important in both cell differentiation and cell development and in the ability of the cell to respond to environmental changes. |
The use of biological agents to develop goods and technologies that improve human lives is studied under this topic. This involves the use of genetic engineering, cloning, and medicine and biofuel development. |
Bacteria and archaea are kinds of prokaryotic microorganisms. Bacteria exist in several different ecological environments, archaeons tend to be in extreme environmental conditions. Both organisms have greater ecological roles in nutrient cycling and biotechnology. |
A virus is a small infectious agent that requires a living host cell for replication. It possesses genetic material, DNA or RNA, enclosed in protein. Viruses infect all life forms-from bacteria to humans-causing diseases. |
Evolution is the gradual modification of species in such a way that life becomes diverse. It is driven by natural selection, mutation, and genetic drift. The Tree of Life maps the relationships among organisms, providing a visible guide to their evolutionary history. |
From the least simple single-celled organisms to the most complex biodiversity today, life has been in existence on Earth for billions of years. Some key events included in this topic are the origin of life, the rise of multicellular life and mass extinctions. |
Ecology is the interaction of living organisms among themselves and with their environment. Learn more about ecology, ecosystems, population dynamics, food chains, and the impact of human activity on natural habitats: |
Biodiversity refers to the variety in life on Earth which includes species diversity, ecosystem diversity, and genetic diversity. Learn more about biodiversity and conservation here: |
It includes the structure, function, growth, and reproduction of plants. The process of photosynthesis, transpiration and the ecological role of primary producers are studied under this topic. |
Biology as a science is deeply rooted in history and evolved significantly over time.
Before the term biology was adopted, disciplines such as Natural History defined the study of plants, animals and fungi in their natural environments, and those who studied it were called natural historians or naturalists. Other disciplines also include Natural Theology and Natural Philosophy.
The word "Biology" was coined by Michael Christoph Hanow in 1766 and independently by Thomas Beddoes, in 1799, Karl Friedrich Burdach, in 1800, Gottfried Reinhold Treviranus, in 1802 and Jean-Baptiste Lamarck, in 1802.
The early human beings survived by knowledge of plants and animals, which was passed from generation to generation. More significant steps in Biology came with the transition from hunting and gathering into farming, furthering knowledge of agriculture and animal domestication.
Biology as a branch came into shape from early contributions by Aristotle. It was significantly developed during the 19th century with various discoveries and experiments.
Given below is the list of major scientists and their contributions which formed a base for the understanding of various concepts in Biology:
Scientist | Title/Contribution | Discovery/Explanation |
Aristotle | Father of Biology | Classified organisms as plants and animals, proposed scala naturae, also known as the Great Chain of Being and conducted studies on animal anatomy and reproduction. |
Hippocrates | Father of Medicine | Founded human anatomy and physiology through the Hippocratic Corpus; established medicine as a unique science separate from philosophy and superstition. |
Theophrastus | Father of Botany | Wrote Historia Plantarum, which began studies on botany dealing with the classification of plants, plant growth, and plant reproduction. |
Galen | Early Medical Pioneer | Contributed to anatomy and physiology, including studies on the circulatory system, bones, muscles, and nerves derived from animal dissections. |
Andreas Vesalius | Father of Modern Anatomy | Conducted human skin dissections; corrected many of Galen's anatomical mistakes; wrote De Humani Corporis Fabrica. |
William Harvey | Pioneer of Cardiovascular Physiology | The first one to describe the blood circulation pumped by the heart; his book De Motu Cordis is considered the foundation of circulatory physiology. |
Anton van Leeuwenhoek | Father of Microbiology | First to view microorganisms (bacteria, protozoa) with the help of homemade microscopes and allowed microbiology and cell theory to begin. |
Robert Hooke | First to Identify Cells | Came up with the term "cell" after observation of cork structure under the microscope; published findings in Micrographia. |
Carl Linnaeus | Father of Taxonomy | Binomial nomenclature-Systema Naturae: provided the uniform system for naming and classification of species. |
Jean-Baptiste Lamarck | Early Evolution Theorist | Lamarckism or the proposal that organisms acquire traits in their lifetime and pass it on to the offspring was also given by him, though the same was proved wrong. |
Matthias Schleiden & Theodor Schwann | Founders of Cell Theory | Co-proposed the theory that states that all living organisms are made up of cells and are the basic units of life. |
Martinus Beijerinck | Father of Virology | In his study on TMV, the highly infectious tobacco mosaic virus, he discovered viruses as infectious agents much smaller than bacteria. |
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As a field of science, biology helps us understand the living world and the ways its numerous species (including humans) function, evolve and interact. Advances in medicine, agriculture, biotechnology, and many other areas of biology have brought improvements in the quality of life. Fields such as genetics and evolution give insight into the past and can help shape the future, and research in ecology and conservation informs how we can protect the precious biodiversity of this planet.
Biology graduates can pursue a variety of careers, some of which may require additional education. A person with a degree in biology could work in agriculture, health care, biotechnology, education, environmental conservation, research, forensic science, policy, science communication, and many other areas.
The best Biology books for exam preparation are:
Biological Evolution:
Basics of Photosynthesis:
Biology is the science that deals with studies about life and living organisms, their structure, function, growth, evolution, distribution, taxonomy, methodology of study, and their interaction with the environment.
Biology has helped us understand the natural world, human health, environmental issues, and interdependencies of life forms. It assists in the furtherance of medicine, agriculture, and biotechnology.
Some major divisions or branches of biology include the botany-study of plants, zoology-study of animals, microbiology-study of microorganisms, genetics, and ecology.
The term "biology" was independently derived by several scientists like Michael Christoph Hanow and Jean-Baptiste Lamarck in the late 18th and early 19th centuries.
There is some overlap between biology and chemistry, physics, and mathematics in the fields of biochemistry, biophysics, and theoretical biology that explain life from the molecular and physical perspective.
Aristotle is also made famous and has been attributed as the "Father of Biology" simply because of the broad studies he conducted and the classification he did on all living organisms from animals to plants.
Maria Sibylla Merian is known as the "Mother of Biology" because she did the fundamental work in the field of entomology and took the records of the life cycles of insects.
Aristotle is known as the "Father of Zoology" because he laid down the very foundation of animal behavioural study, anatomy, and classification.
Martinus Beijerinck is considered the "Father of Virology" because he discovered viruses as infectious agents, especially through his work on the tobacco mosaic virus.
Biology is the scientific study of living organisms, their structures, functions, growth, and interactions with each other and their environments.
The 15 branches of biology are:
The father of the cell in biology is Robert Hooke.