What Are The Main Branches Of Biology And Their Definition

By Mary Smith. Updated: December 7, 2017
What Are The Main Branches Of Biology And Their Definition

Biology is the science that studies living organisms. However, as a science it has multiple branches that intend to study issues such as evolution, nutrition, morphogenesis, reproduction etc. There are a total of seven fields from which each branch hangs: animal , evolutionary, medical, environmental, microscopic structure, chemistry related and other miscellaneous issues.

If you are interested in knowing a little more on each and every field, we show you what the branches of biology are.

You may also be interested in: What Are the Main Branches of Chemistry

Cellular biology

Cellular biology or cytology is the branch of biology which studies the structure and function of cells. This discipline is responsible for understanding among other matters the properties, structures and functions of these as well as their interaction with the environment. Undoubtedly, it is a fairly wide field which started being studied following the invention of the optical microscope.

Within this branch we find the following fields:


This is is the branch of cellular biology that specifically studies living cells including their specific properties, their physical structure, chemistry and division in order to understand how they interact with nature.


This field solely focuses on the cellular tissue which is studied from a microscopic point of view.


Microbiology, a science or branch of biology that focuses on the study of microorganisms, which are the smallest living things. These organisms are completely invisible to the human eyes, they are only visible through the use of a microscope. It focuses on how microorganisms affect others.


This is the specific study of particles found in the air water or other deposits such as grain, spores and pollen; focusing on how they interact with nature.


This is the specific branch that studies Protists, which are eukariotic organisms that cannot be specifically classified as either animal, plant or fungi but are more similar in characteristics to algae.

What Are The Main Branches Of Biology And Their Definition - Cellular biology

Molecular biology

Also, molecular biology is the discipline which studies the biological processes on a molecular level. The truth is that this branch shares elements of biology with chemistry, particularly genetics and biochemistry. It focuses mainly on studying the interactions of different cell systems.

Bio-engineering is a hybrid that is also related to chemical biology, which aims to research engineering techniques related to biology when using this knowledge on products.

Evolutionary biology

This branch of biology solely focuses on biology from an evolutionary point of view in order to predict how biology will evolve by studying how it has done so in the past thanks to these fields:


This particular branch of biology studies the way in which all living creatures and organisms distribute and have done during history in a geographical point of view.

Developmental biology

Developmental biology is the branch of biology that studies the development of living organisms from birth until death. A less superficial description would state that this discipline studies the processes by which organisms grow. So it focuses on the genetic control of cell growth and cell differentiation and morphogenesis.


This is the study that focuses only on the traces left by living creatures in the past in order to study its activity such as old footprints, trails, burrows...


Morphology is closely related to developmental biology, as it studies and classifies the structure and the form of all living organisms.


Paleontology is the branch that studies basically fossils left basically by prehistoric means of life in order to understand past times. For more information, take a look at the practical uses of paleontology.

Evolutionary biology

This branch of biology focuses on how different forms of life are currently changing and studies how they are creating brand new forms of life.


This branch studies how heritage and a living being's phenotypes can alter nucleotide sequences in their genetics.

Marine biology

Marine biology is the branch of biology that is responsible for studying all the creatures that live within the marine environment. This discipline engulfs a series of specialisations that are centred in more specific areas. And so, amongst these, we can highlight ichthyology, which directly studies fish; malacology, which studies molluscs; phycology, which centres around the study of seaweed; cetology, which studies marine mammals. Learn what you can do with a marine biology degree here!

What Are The Main Branches Of Biology And Their Definition - Marine biology

Medical biology

Medical related branches of biology study all fields that are related to illnesses, alterations and functions of the human body.


Physiology is the study of the functions of living beings. A branch that deals with studying the respiratory, reproductive, nervous system etc. Also, within physiology, and depending on the type of living organism, we can distinguish between three groups of plant physiology, animal physiology and lastly human physiology.


Genetics is an exciting branch of biology that attempts to study biological heritage which is transmitted from generation to generation. It is a fairly complex branch whose main object is the study of genes formed by segments of DNA and RNA.


This field of biology is in charge of studying the structure of any multi-cellular organism at a naked eye, i.e. macroscopically. In turn, it can be divided into three areas of study: human anatomy, zootomy (animal anatomy), and phytotomy (which is plant anatomy).


As you may have already guessed by now, embryology is the study of all embryos.


This branch studies the endocrine glands in order to understand the function of hormones and how they act in a human body.


This field studies how diseases or epidemics affect living population ans well as researching its successful control and eradication.


Last but not least, immunology focuses on the study of how the immune system works in the body and also experiments on how it can be built.

What Are The Main Branches Of Biology And Their Definition - Medical biology

There are also other important branches in the field of medical biology,which are the following:

  • Medicine
  • Neurology
  • Parasitology
  • Physiology
  • Koliology
  • Mastology
  • Pharmacology
  • Virology
  • Urology
  • Toxicology
  • Surgery
  • Splanchology
  • Pathology


Mycology is the branch of biology which studies solely fungi. It focuses on each and every part of their characteristics and how they interact with the environment.

What Are The Main Branches Of Biology And Their Definition - Mycology


Zoology is the discipline responsible for study animal life as a whole, focusing on their development behaviour and physiology. As in the rest of the main branches of biology, here there are some sub disciplines as can be aquariology or aracnology, to name a few. Take a look in all the careers there are in Zoology if you're interested in this field as, within this field we find the studies of:

  • Entomology
  • Herpetology
  • Ichthyology
  • Mammalogy
  • Ornithology
  • Nothology
  • Primatology
  • Veterinary science


We also have botany, the discipline of biology that deals directly with the study of plants. It is a very large branch as it studies everything that has to do with the plant world. Through it we can classify, describe, identify and learn about reproduction, morphology or physiology of the natural beings of the plant world. To discover more about botany, you may be interested to know who the father of botany is.

What Are The Main Branches Of Biology And Their Definition - Botany

Environmental biology

All branches of biology that concern the way in which all the elements of the environment interact with each other and the way they influence are grouped in this field.


This particular branch studies all organic particles that can be found in the air, how they travel, reproduce and act.


This is the branch that specifically studies how changes in the climate can affect the living beings existing in one area


This field which is also closely related to chemical biology studies how nutrients affect every living cell through metabolism . This field is useful in many other branches of biology such as botany, molecular biology and genetics.


Ecology is the branch of biology that is responsible for studying the relationship of living beings on the planet with their natural habitat. So it is the study of everything that affects the adaptation of living organisms to their different habitats, as an be climate or geology.


This field meets with another discipline: geology. It relates to this subject by studying how organisms interact with their surroundings and environment.

Now you know the main branches of Biology you may also be interested in learning the different branches of Philosophy.

If you want to read similar articles to What Are The Main Branches Of Biology And Their Definition, we recommend you visit our University degrees category.

Write a comment about What Are The Main Branches Of Biology And Their Definition

What did you think of this article?
Micheal yakubu
prem dilwala
its very easy to understand
Aminu Ibrahim
Well recommended......!!!
Amari Hollis
I want to be a Marine biologist because I like to study and learn new things about creatures. every since
I was a kid I loved sea creatures and other living creatures so I decided to choose Marine biology.
dauda kingsley okrah
I need all the beaches
are you don't know the branches of biology
with detail
Raja Shahid khan
What is the basic difference b/w RNA & DNA?
adebayo victor olawoye
question:brief histary of biology
Sunday Ngbakor
This articles are very useful and educating
shahbaz siyal
thankyu for information

What Are The Main Branches Of Biology And Their Definition
1 of 6
What Are The Main Branches Of Biology And Their Definition

Back to top