Biology Topics (Explained For You)

by Dave

Wow! Did you know how many sub-disciplines there are in biology? Some topics cover the bigger picture, and there are topics on small biology, anatomy and health, and macro-organism topics. There are numerous interdisciplinary sub-disciplines, historical biology fields, and multiple branches on development and growth. Read about the many others also discussed.

Biology as a whole looks at everything that has to do with life and living things. Life is a tricky concept that we still don’t fully understand, but there are some basic concepts that we use to define it. For example, cells are considered the base unit of life, and evolution is considered the driving force of change which occurs through genetic heredity. Because of the great diversity of life, there are many different topics of specialization in biology. Below are introductions to some of them to give you a feel for just how intricate the field is. Additionally, for more details check out articles about current events, scientists, and more.

Biology Topics That Cover the Bigger Picture

General Biology

General biology provides a platform for a basic introduction to the study of life. The main focus starts on cells, including their functions and structure, cellular energy, cell transport, and how they divide. Students of general biology also learn about topics such as DNA and genetics, as well as evolution and ecology. Courses in this area are intended to cover the potential interests of biology students who want to acquire skills and knowledge in various disciplinary areas.


This topic is one of the more broad and diverse in biology due to its scope. Ecology explores how organisms interact with each other and their surrounding environment, often looking at whole ecosystems. Topics of interest include the diversity of life in ecosystems, its distribution, overall biomass, and interactions between species. It also looks at how both biotic and abiotic variables on individuals. Biotic factors are living parts of the systems such as animals and microorganisms. Abiotic factors are the nonliving parts such as chemicals or geography.

Big Topics on Small Biology

Biology Topics on the Molecular Level

Molecular Biology

Molecular biology is a sub-field that entails the molecular basis of biological activity in biomolecules in the different systems of a cell. This includes the interrelationships between protein, RNA, and DNA, as well as their biosynthesis and the different ways these interactions are regulated. Molecular biology requires specific techniques that are sometimes combined with ideas from biochemistry and genetics.

Structural Biology

Structural biology is a branch of molecular biology that studies how molecules form. Scientists view the molecules in three dimensions to show how they function and interact. Structural biology has helped in understanding ways that different molecules work and how they keep us healthy or make us sick.

Biology Topics on Cells and Microorganisms

Cell Biology

Cell biology is the study of the functions and structure of the cell. This is probably one of the most fundamental topics in biology given that cells are considered the basic units of life. The field seeks to understand cell physiology, cell life cycles, and cell structure. There are many types of cells that can specialize in certain functions. Exploring these functions leads to a detailed understanding of the organisms and tissues that cells compose.


This is a branch of biology that deals with the study of organic particles that the air transports from one place to another. Such particles include pollen grains, fungal spores, bacteria, viruses, and even small insects. The key is that the transport is passive, meaning the particles or insects don’t have much of a say in where they’re going. The topic involves the study of these airborne biological particles, their movement, and the impact they have on animals, humans, and plant health.


As the name suggests, bacteriology is the branch of biology that specializes in the study bacteria. It looks at their ecology, morphology, biochemistry, genetics and other related aspects. This subdiscipline of microbiology also covers the identification, characterization, and classification of bacterial species. These tiny species are important to us because they can have huge effects on our own health. Thus, the field is particularly important in fields such as medicine, agriculture, and the agricultural industry.


Microbiology can be defined as the study of microscopic organisms like protozoa, virus, fungi, bacteria, and archaea. This topic in biology studies microorganisms whether they are unicellular (single cell), acellular (lacking cells), or multicellular (cell colonies). The field also includes fundamental research on the physiology, cell biology, ecology, evolution, biochemistry and essential aspects of microorganisms.

Anatomy Biology Topics


This topic in biology is the description and identification of the structure of living organisms, especially those larger organisms with systems of parts and organs. It is a branch of medicine and biology that can be broken down into three main categories: human anatomy, zootomy, and plant anatomy. It focuses on the structure, composition, and location of the parts of organisms and examines the relationship between these parts.


Histology, also known as microanatomy, is a biology topic that studies the tissues of plants and animals using microscopy. It looks at microscopic structures of biological material and how they are functionally and structurally related. Additionally, histology primarily uses an electron or light microscope, on specimens that have been sectioned, mounted, and stained on slides.

Health Biology Topics


Cytotechnology is a specialization that uses microscopic interpretation of cells to detect different cell abnormalities such as cancer. This involves a thorough examination of samples collected from areas such as body cavities, gastrointestinal tracts, the uterine cervix, or lungs. Cytotechnologists put the cells of these areas on glass slides and use microscopes to evaluate them for potential cellular anomalies. Some labs use computers for initial evaluations and then have humans come in for further analysis. Abnormal samples will then go to pathologists to determine diagnoses.


Immunology is a field of biology that entails the study of the immune system of all organisms. The physiological functions of the immune system and the physiological and chemical components of the immune system are all subjects of study in this field. Thus, it works to measure, contextualize, and chart the malfunctions of the immune system in different immunological disorders. Examples include autoimmune diseases, immune deficiencies, and transplant rejection.


Virology deals with the study of viral diseases and the viruses that cause them. Although viruses are not technically considered alive, they still fall into the field of biology because they fit many characteristics of microorganisms. The viruses also affect living hosts, making it crucial to understand them and their effects. The discipline focuses on the ways viruses infect their host, the techniques to isolate them, the interactions with the hosts, and the different diseases they cause.

Biology Topics by Type off Macro-Organism

Topics on the Biology of Non-Animals


Botonay refers to the scientific study of plants. It is a branch of biology that explores the biochemical processes, properties, and structure of plants. The principles and research of botany often provide the groundwork for applied sciences like forestry, horticulture, and agriculture. By studying plants, the field seeks to understand environmental impacts, classifications, life processes, diseases, and interactions associated with the plants and their surroundings. This includes plants in their natural state, our interactions with them in the wild, and our interactions with them in controlled environments to cause desirable changes.


Mycology can be defined as the study of fungi, including yeast and mushrooms. It is the branch of biology that studies fungi with their biochemical and genetic properties. Mycology research has helped in the development of different antibiotic drugs like streptomycin, tetracycline, and penicillin, as well as other drugs like statins. Mycology is also important in baking, wine making, dairy, and in the production of inks and dyes.

Topics on the Biology of Animals

Human Biology

This sub-field of biology encompasses human populations and human beings. It focuses on all aspects of human organisms including anatomy, physiology, ecology, genetics, nutrition, anthropology, and more. This makes it a very interdisciplinary field despite its relatively narrow focus in the animal kingdom.

Marine Biology

Marine biology is the intensive study of marine organisms, their interactions, and behavior with the environment. This often focuses on animals, however it can also include plants and other organisms because the topic is very extensive. Marine biologists often specialize based on a particular behavior, species, group, ecosystem, or technique. Since this discipline is a research and learning field, most marine biologists work in coordination with educational institutions like universities.


The biology topic of zoology is also known as animal biology because it involves the scientific study of the animal kingdom. This study includes classification, habits, embryology, evolution, and distribution of all the animals on Earth. The goal of the field is to develop practical applications and increase scientific knowledge in different fields.

Interdisciplinary Biology Topics


Otherwise known as biological chemistry, biochemistry is the topic of biology that covers the chemical processes that all living organisms undergo. It is a lab-based science that combines chemistry and biology with the aid of chemical techniques and knowledge to solve problems in all areas of modern biology. Experiments in this area involve applying chemistry techniques to biological processes at a molecular and cellular level. The three main fields of biochemistry include metabolism, molecular genetics, and protein science.


Electrophysiology can be defined as the scientific field of study of the electrical and physical properties of biological tissues and cells. It also involves the measurement of electric current or manipulations or voltage changes on a wide variety of scales from whole organs to single ion channel proteins. One application of the field is the study of the electrical activity of the heart to find the location of an arrhythmia.


This topic in biology looks at how biology can combine with technology to create products. It studies living organisms and their biological systems to determine their potential uses and applications in products that humans use. In this manner, biotechnology harnesses biomolecular and cellular processes to create products that can primarily improve health care, agriculture, and food production, but also some other miscellaneous applications in other fields. This field started in the early 19th century, making it relatively new in the scheme of applied sciences.


Cryobiology gets its name from from the Greek words of cold, life, and word. Thus, it gives us the word on life in the cold. It is the topic of biology that examines the effects of low temperatures on living organisms at temperatures below what they would consider normal. So, if a tissue functions normally at room temperature, then this field studies the effects of temperatures below that. These methods can help us figure out how to store and preserve tissues and cells for long-term storage purposes. It can also function as a tool to target and destroy unhealthy tissues.

Topics that Mix Biology and Math

Mathematical Biology

Mathematical biology is a sub-field of biology that deals with theoretical analysis, mathematical abstractions and models of living organisms. By doing so, it tries to explain the principles that governs the behavior, structure, and developments of the systems. It is basically the opposite to experimental biology which deals with experimental conditions to validate and prove scientific theories.

Computational Biology

Similar to bioinformatics, computational biology is a branch of science that uses biological data to build models or algorithms. These algorithms aim to understand biological relationships and systems. They use experimental data and utilize various methods from different computational and mathematical fields to study biological systems. Additionally, the field can provide insights into how these systems work, how they interact, and even how they result in certain biological behaviors. Related fields include biophysics, computer science, statistics, mathematics, and chemistry.

Biology Topics Digital illustration of a dna

Historical Biology Topics

Evolutionary Biology

This biology topic is fairly recent but critical to our understanding of life on earth and its origins. First, it starts with the knowledge of all life beginning from a sole common ancestor. Then it analyzes the evolutionary changes that created the diversity on Earth today. These processes include common descent, natural selection, and speciation. As a branch of the biological sciences, it explores the origin of life and the adaptation and diversification of life forms over time.


Paleobiology is a comparative and growing new discipline that combines the findings and methods of the Earth science paleontology with the findings and methods of the natural science biology. The discipline obtains data from paleontology and biology and tries to mold them together. Therefore, research in the field consists of looking at fossils for clues about molecular evolution of the history of life.

Biology Topics on Development and Growth


Genetics is the study of biologic processes where parents pass on a set of genes onto their offspring. These genes determine certain characteristics in organisms and are of interest for enhancing the good and preventing the bad in terms of health. Children inherit genes from both biological parents, and these genes showcase specific traits. The traits can include obvious aesthetic and behavioral signs. Alternatively, they may be hidden within the body or manifest themselves as diseases and disorders.

Developmental Biology

Developmental biology is the study of the processes that makes organisms grow and develop. Thus, the topic includes areas such as regeneration of limbs and other parts, metamorphosis, differentiation of stem cells in fully grown organisms, and asexual reproduction, to name a few. As a field of study, it mainly focuses on morphogenesis: the process that forms organs, tissues, and anatomy. Knowledge of these typical developmental processes can help in understanding abnormalities and medical conditions. For example, the cause of cancer is unabated and invasive cell growth which we have yet to figure out how to stop.


Embryology is the biology topic that looks at pre-birth development. This entails the process starting at fertilization and going through prenatal development of gametes, embryos, and fetuses. Embryology also encompasses the in-depth study of congenital disorders. These disorders occur in the womb before birth and their study involves comparative and descriptive studies. The field has made improvements in preventing birth defects and keeping both mother and child healthy throughout the gestation process.

Biology Topics by Systems


Chronobiology is a biology topic that studies the effects of day-night cycles on the body. The emotional, physical, and mental states of people (as well as other animals) change in a periodic manner due to the rhythm of day and night on Earth. These are known as biological rhythms. Some examples include animals being active during certain times of the day, the menstrual cycle, gene oscillations, and circadian regulatory systems. Other relevant topics that interact with the field are genetics, physiology, and molecular biology.


Eccrinology can be defined as a branch of anatomy and physiology that deals with the secretory glands and secretion. Eccrine glands serve as the major gland that is found in the majority of all skin of the human body. They produce an odorless, clear substance that consists primarily of Sodium Chloride (NaCl) and water. Sodium Chloride is also reabsorbed to reduce the loss of salt in the human body.


The endocrine system contains various organs that release hormones into the circulatory system to regulate other organs. Hormones are chemicals that cause the actions of several organ systems in the human body. It’s a complex system that gives rise to the biology topic of endocrinology that aims to understand the roles of the hormones, tissues, and glands that all work together in the body. Endocrinology is an essential field because hormonal imbalance is the reason for many medical conditions. For example, the thyroid hormones, insulin, and growth hormones are crucial for a fully developed body.


Xenobiology is a field in synthetic biology that deals with manipulating and synthesizing biological systems and devices. It comes from two words “xeno” and biology. Xeno is a Greek word that means guest. Therefore, it describes a branch of biology that doesn’t yet exist in nature and is not yet familiar to science. It is closely related to astrobiology and exobiology that deal with the study of extraterrestrial life forms. All involve studying possibilities and preparing for future advances and discoveries.

Biology Topics That Mix the Brain and Body


Neuroscience as a topic in biology is a medical study that explores the human nervous system. It is a multidisciplinary field that combines important disciplines like molecular biology, physiology, developmental biology, anatomy, cytology, psychology, and mathematical modeling. Through this diverse range of fields it works to understand the emergent and fundamental properties of neural circuits and neurons.


Physiology is a field of science that studies how biomolecules, cells, organs, organ systems, and the whole system carry out physical and chemical functions to support life. The interaction between the physical and chemical parts of the body creates an interesting but complicated area of study. Fundamental areas in the field include homeostatic control mechanisms, communication between cells, as well as biochemical and biophysical phenomena.