Biology vs Chemistry: Your Guide to Choosing PhD Science Majors

Biology and chemistry are two of the most common scientific fields that attract a large number of students for doctoral studies. Regardless of being classified as science fields, both biology PhD and chemistry PhD have distinct features that separate them from each other.

While biology belongs to life science, chemistry comes under physical science. Students planning to pursue a research career in the field of science often get confused about which subjects to choose as their PhD major. As both biology and chemistry have their own unique features and advantages, getting an in-depth understanding of both fields can help students make an informed decision.

If you are planning to pursue a PhD in science soon and can’t decide which science major to choose, this guide will provide all the information that is necessary to choose between biology and chemistry plus PhD research help.

student getting phd research help for phd science

Overview of Biology PhD

Biology is the study of living organisms and their interactions with each other as well as the environment. Due to the comprehensive nature of biology, it includes a wide range of fields and specialisations. Students aiming to pursue a PhD in biology can select one or more of these specialisations based on their personal interests and career goals. Each of these fields gives students a unique opportunity to develop expertise and learn skills that can be applied in a practical scenario.

Some of the common sub-divisions of biology are listed below:

  • Molecular biology
  • Cellular biology
  • Microbiology
  • Ecology
  • Virology
  • Zoology
  • Marine biology
  • Genetics
  • Immunology
  • Botany
  • Biotechnology
  • Neuroscience
  • Developmental biology

These fields allow PhD students to explore the minute details of living creatures. It enables them to conduct an in-depth analysis of everything from the smallest cells to the largest ecosystems. As a PhD student in biology, you will engage in rigorous coursework that includes experimentation, data analysis and critical thinking. At every stage of your PhD, you will develop an understanding of the fundamental processes that govern life.

With the advancement of technology, several sub-divisions of biology now use technical tools and resources to address their challenges. This interdisciplinary approach gives students a platform to learn modern biology and develop a holistic research approach. Moreover, it gives students a platform to contribute to the advancements of fields such as biotechnology or bioinformatics.

Overview of Chemistry

Chemistry, on the other hand, is the field of science that explores the various principles of matter and its transformation. It focuses on the composition, properties and reactivity of matter. A PhD in chemistry helps students develop the skills needed to investigate the composition, structure, properties and reactions of substances. These substances can range from the smallest particles, such as atoms and molecules, to complex materials and compounds.

Similar to biology, chemistry is also divided into multiple sub-disciplines. Some of the common sub-divisions of chemistry include:

  • Organic chemistry
  • Inorganic chemistry
  • Physical chemistry
  • Analytical chemistry
  • Biochemistry
  • Environmental chemistry
  • Medicinal chemistry
  • Material chemistry
  • Surface chemistry
  • Nuclear chemistry

These sub-divisions of chemistry allow researchers to delve deep into the workings of atoms and molecules and get a clear understanding of the fundamental aspects. PhD chemistry researchers can often find themselves engaging in advanced laboratory work. In the laboratory, you will be employing sophisticated techniques to synthesise, analyse and understand the behaviour of various substances.

With your expertise, you can also help institutions explore the intricacies of molecular structures, develop new materials or advance their existing knowledge of chemical processes. Similar to biology, chemistry is also an interdisciplinary field that can be combined with different branches of physics and biology. This gives PhD science researchers a chance to work on collaborative projects and improve their understanding of different areas of research.

Career opportunities for biology researchers

A PhD is one of the higher degrees that students can pursue in the field of biology. Upon successful completion, researchers are eligible for different job roles in academic, governmental and industrial fields. Some of the popular career options for biology researchers are as follows:

  • Research scientist
  • Postdoctoral fellow
  • University professor
  • Academic researcher
  • Research and development
  • Biotechnology expert
  • Pharmaceutical advisor
  • Environmental scientist
  • Microbiologist
  • Wildlife biologist
  • Medical expert
  • Management consultant

While the above are the common career paths that most biology researchers take after their PhD, the job responsibilities may vary between different organisations and regions. In addition to this, biology researchers can find themselves working with non-profit organisations or government agencies as a part of a bigger project. Biology researchers are often considered for their expertise and skills that can help address complex issues, improve existing methods and find innovative solutions for the well-being of the environment and society.

Career opportunities for chemistry researchers

Chemistry researchers can have a wide range of opportunities to establish their careers in both academic and non-academic fields. However, the career path you choose may depend on your specialisation, expertise and interests. Some of the common career options that you can choose from are listed below:

  • University professor
  • Research Faculty
  • Postdoctoral researcher
  • Journal reviewer
  • Research and development scientist
  • Process Engineer
  • Quality control specialist
  • Medicinal chemist
  • Pharmaceutical expert
  • Clinical research scientist
  • Material scientist
  • Forensic expert
  • Food and beverage scientist
  • Toxicologist

Since chemistry is a vast field, its applications can be observed in agriculture, food and beverage, manufacturing, pharmaceutical and various other industries. Based on your expertise, you can apply for managerial positions in government and non-profit organisations. Additionally, you can opt for a patent or attorney specialist to help organisations understand the unique features of their products and draft technical documents.

Research focus of a PhD in biology

Biological research often involves experimentation and fieldwork. PhD researchers will have to spend a lot of time conducting research in the lab as well as practical scenarios. However, as biology is a comprehensive field, the research focus may vary between its sub-divisions. For example,

  • Molecular biology investigates the structure and function of biomolecules, such as DNA, RNA and proteins, and their roles in cellular processes.
  • Genetics or genomics involves the study of different traits, genetic variation and the function of genes in organisms. It may also involve genomic sequencing and analysis.
  • Cell biology explores the structure, behaviour and function of cells that exist in different organisms.
  • Developmental biology examines the processes that occur during the growth of plants and animals. It allows students to explore processes such as embryonic development, metamorphosis and tissue differentiation.
  • Ecology helps students study the relationships between living organisms as well as human beings and their environments. It allows students to explore these relationships at the individual, community, ecosystem and biosphere level.
  • Evolutionary biology is defined as the study of the history of life in different forms on Earth. It explores the mechanisms of evolution, adaptation and the diversity of life forms and different species over time.
  • Microbiology investigates microorganisms such as bacteria, viruses and fungi and their roles in health, disease and environmental processes. It is a vast field that consists of other sub-fields such as virology, immunology and bacteriology.
  • Neurobiology helps in understanding the structure and functioning of the nervous system, including the brain and neural circuits, and their roles in behaviour and cognition.
  • Environmental biology focuses on the impact of environmental factors on living organisms. These factors may include climate change, pollution, global warming and conservation.

The research focus of a PhD in chemistry

Chemistry research, on the other hand, revolves around synthesis and laboratory work. As a chemistry researcher, you may focus on developing new materials, understanding chemical reactions or exploring the properties of novel compounds. Some of the common areas in chemistry with their focus are as follows:

  • Organic chemistry deals with the design and creation of new organic compounds with specific properties or functions. It also allows researchers to study the mechanisms, structure, properties and reactions of organic compounds and materials.
  • Inorganic chemistry focuses on the synthesis and behaviour of inorganic compounds. It involves the study of chemical compounds that are not based on carbon.
  • Biochemistry is a study of chemical processes that focuses on living organisms. It is an interdisciplinary area that involves both chemistry and biology and can be divided into structural biology, enzymology and metabolism.
  • Physical chemistry enables researchers to study both macroscopic and microscopic phenomena that occur in different chemical systems. It helps them develop an understanding of the principles, concepts and practices of physics that can be applied in chemistry.
  • Environmental chemistry covers the scientific study of chemical phenomena that occur in different environments. It also explores how chemicals interact with living beings in various scenarios.
  • Pharmaceutical chemistry involves the identification, development and production of new chemical units that are suitable for therapeutic and medicinal use. It allows pharmaceutical companies to test existing therapeutic drug combinations and their effectiveness in treating various health concerns.
  • Agricultural chemistry focuses on the study of chemicals commonly used in growth, production and maintenance of fruits, vegetables and crops. As farming includes the use of different fertilisers and pesticides, agricultural chemistry allows researchers to explore the effect of the chemicals used in these products on farm produce.

Nature of research in a Science PhD

The nature of PhD research in both biology and chemistry is multidimensional, dynamic and highly specialised. Both research programmes consist of a wide range of activities that students will have to participate in during their PhD journey. Regardless of the subject and specialisation you choose, the primary goal of your research will be to make an original and significant contribution to the existing body of scientific knowledge. This often involves designing and conducting experiments, collecting and analysing data and drawing conclusions based on novel findings.

Several universities encourage students to formulate hypotheses for investigating the nature of biological or chemical phenomena. This makes it easier for students to develop experimental designs and choose the right methodologies to find solutions to their research questions.

Moreover, your PhD programme will involve laboratory work, field studies, interdisciplinary collaboration and application of advanced techniques. You may also have to adhere to strict ethical guidelines if your experiments include human participants. Ethical considerations will ensure the safety of participants. It will also help in maintaining the integrity and transparency of methods and results.

Requirements for a PhD Science Applicant

Whether you want to pursue a PhD in biology or chemistry, some common requirements will make you an eligible applicant for both courses. Similar to any other PhD research, pursuing a doctorate in biology or chemistry requires several specialised skills. Due to the extensive nature of both courses, students need to demonstrate a combination of technical, analytical and interpersonal skills.

In addition to this, students must be proficient in different laboratory techniques, depending on the specific focus of their research. Other common skills that you must possess to enrol in a PhD programme include critical thinking, time management, research skills, and problem-solving. As well as, data analysis, communication skills, adaptability, flexibility, collaboration, academic PhD thesis writing and networking.

In addition to this, you must demonstrate academic excellence with a bachelor’s or master’s degree focusing on biology or chemistry as a major subject. To apply for a research programme, you will also have to present different documents. While these may vary depending on your subject area, institution and country, some of the common documents include the application form, curriculum vitae, letters of recommendation, statement of purpose, and academic transcripts. Some courses may also require standardised test scores, a research proposal, previous publications and scores on the English language proficiency test if applying abroad. Remember to seek PhD application help if you struggle with any requirements.

Along with these documents, students are required to pay a small application fee to the university they are applying to. Once approved, you may get a response from the university inviting you for an interview for the applied research position. This interview will not only help the university analyse your skills and academic knowledge but also give you a chance to meet your potential supervisor and discuss your concerns before the start of the programme.


Starting a PhD is one of the most difficult decisions of a student’s life. Before selecting a PhD programme, it is important to completely understand its requirements, the nature of research and potential career options. Both biology and chemistry can offer exciting opportunities for contributing to scientific knowledge and making a meaningful impact on society. Depending on your skills, expertise, interests and future goals, you can select a PhD science major that aligns with your preferences.