Biology Degree Requirements

You are searching this because you want to know if you can actually handle the course load. Biology has a reputation as a "weed-out" major, and there is some truth to that — particularly in the chemistry sequence that every biology major must complete. But the difficulty is not about raw intelligence. It is about time management, consistent study habits, and willingness to ask for help early instead of late.

The National Center for Education Statistics reports that biology is one of the most popular STEM bachelor's degrees awarded in the United States, with tens of thousands of graduates each year¹. The majority of those students were not child prodigies. They were organized, persistent, and strategic about how they spent their study time.

For the broader view of where this degree leads, see the biology degree overview. This page covers the specific coursework and requirements you will face.

Core Coursework: What Every Biology Major Takes

Biology programs follow a structured sequence where each course builds on the one before it. Skipping or delaying courses in the sequence pushes back your entire timeline.

Foundational courses (first two years):

• General Biology I and II (with labs) — cell biology, molecular biology, genetics, evolution, ecology, and organismal biology. The full survey of the discipline. Labs involve microscopy, dissection, experimental design, and data analysis.
• General Chemistry I and II (with labs) — atomic structure, chemical bonding, stoichiometry, thermodynamics, kinetics, and equilibrium. These courses are prerequisites for organic chemistry and biochemistry.
• Organic Chemistry I and II (with labs) — the course sequence that defines the biology and pre-med experience. Reaction mechanisms, functional groups, synthesis, and spectroscopy. The difficulty is real but manageable with consistent daily study.
• Calculus I (sometimes Calculus II) or Biostatistics — the math requirement varies by program. Some require calculus-based physics and two semesters of calculus; others accept statistics-based alternatives.
• Physics I and II (with labs) — mechanics, electricity, magnetism, optics, and modern physics. Required for pre-med students and most biology programs.

Upper-level biology courses (junior and senior years):

• Genetics — Mendelian and molecular genetics, gene expression, and genomics
• Cell Biology — cellular structure, signaling pathways, and molecular mechanisms
• Biochemistry — protein structure, enzyme kinetics, metabolism, and molecular biology. Often cross-listed with chemistry.
• Ecology — population dynamics, community ecology, and ecosystem science. Usually includes a field component.
• Physiology — organ systems and their functions, often focused on either animal or plant physiology
• Evolutionary Biology — mechanisms of evolution, phylogenetics, and speciation
• Senior Seminar or Capstone — reading primary literature, designing experiments, and presenting research

Lab courses are a defining feature of the biology major. Nearly every core science course has an associated lab (3-4 hours per session, once per week) on top of the lecture. Labs are graded separately and require pre-lab preparation and post-lab reports.

BA vs BS: Which Track Is Right for You?

Most biology programs offer both options, and the difference matters.

BS in Biology — the standard pre-professional and pre-graduate school track. Requires more science and math coursework, including the full chemistry and physics sequences, calculus, and more upper-level biology electives. This is what medical schools and most graduate programs expect.

BA in Biology — fewer science requirements, more room for liberal arts electives, double majors, or minors. Suitable for students planning careers in science education, science writing, public health, or environmental policy where a science foundation is useful but the full research-track preparation is unnecessary.

If you have any intention of applying to medical school, dental school, veterinary school, or research-focused graduate programs, take the BS track. The additional science courses are not optional for those paths — they are prerequisites for admission.

Common Concentrations and Specializations

Molecular and cellular biology — focused on the chemistry of life at the cellular level. Strong preparation for biomedical research, pharmaceutical careers, and MD-PhD programs.

Ecology and evolutionary biology — field-oriented study of organisms in their environments. Leads to careers in conservation, environmental consulting, and wildlife management.

Genetics and genomics — DNA, gene expression, and computational biology. One of the fastest-growing areas given advances in genetic technology and personalized medicine.

Microbiology — bacteria, viruses, fungi, and their roles in health, disease, and ecology. Strong career demand in clinical labs, public health, and biotechnology.

Neuroscience — sometimes offered as a concentration within biology, sometimes as a separate major. Brain structure, neural signaling, and behavior.

Pre-medical track — not a formal concentration but a set of courses that overlay with the biology major: general chemistry, organic chemistry, biochemistry, physics, statistics, and specific biology courses required for medical school admission.

Prerequisites and Admission Requirements

University admission — no special prerequisites for declaring biology as an intended major at most schools. Standard high school preparation in science and math (biology, chemistry, algebra II, and ideally pre-calculus) gives you a solid starting point.

Course prerequisites create a rigid sequence:

• General Chemistry I is prerequisite for General Chemistry II
• General Chemistry II is prerequisite for Organic Chemistry I
• Organic Chemistry I is prerequisite for Organic Chemistry II
• General Biology I is prerequisite for most upper-level biology courses
• Calculus or statistics may be prerequisite for physics and some biology courses

If you arrive at college needing to start with pre-calculus or a chemistry prep course, your timeline shifts by one semester. This is not fatal, but it means planning ahead to stay on track for a four-year graduation.

GPA requirements — many biology programs require a 2.0 or 2.5 in major courses to continue. Pre-med students need significantly higher GPAs (3.5+) to be competitive for medical school admission. If you are planning for college in high school, take the strongest math and science courses available to you.

Skills You'll Build (and What Employers Actually Value)

Experimental design and scientific method — designing controlled experiments, collecting data, and drawing evidence-based conclusions. This is the core intellectual skill of the degree and transfers to any analytical career.

Laboratory techniques — microscopy, spectrophotometry, gel electrophoresis, PCR, cell culture, and data analysis. Hands-on technical skills that are directly employable in biotech, pharmaceutical, and clinical laboratory settings.

Quantitative reasoning — analyzing data, understanding statistics, and making evidence-based arguments. The combination of biology and chemistry training produces strong quantitative thinkers.

Scientific communication — writing lab reports, literature reviews, and research papers in a precise, evidence-based format. Presenting findings to technical and non-technical audiences.

Critical reading of research — evaluating published studies for methodology, statistical validity, and conclusions. This skill is valuable far beyond biology in any field that relies on evidence-based decision-making.

What Nobody Tells You About Biology Requirements

Organic chemistry is a study-skills problem, not an intelligence problem. The students who fail organic chemistry are overwhelmingly the ones who try to memorize reactions instead of understanding mechanisms. Work practice problems daily, attend every office hour, and form a study group. Students who do these three things consistently pass. Students who cram before exams do not.

Lab reports take longer than you think. A four-hour lab session generates a report that takes 3-6 hours to write properly. When you are taking two or three lab courses simultaneously, the writing load is substantial. Budget time for reports the same way you budget time for exams.

Research experience is not technically required but practically essential. For graduate school or medical school admission, independent research experience with a faculty member is expected. Start looking for research opportunities during your sophomore year. Most professors are willing to take on undergraduates who are reliable and willing to learn, but spots fill up and early interest gives you an advantage.

The freshman biology course is deceptively broad. General Biology covers everything from molecular genetics to ecosystem ecology in two semesters. The breadth means each topic gets limited depth, which makes the course feel like memorization. Upper-level courses go much deeper and reward understanding over memorization — the major gets more interesting as you advance.

Summer courses can save your timeline. If you fall behind in the sequence (failed a prerequisite, started in pre-calculus, changed majors late), summer sessions for chemistry or physics can get you back on track without delaying graduation. This is especially important for pre-med students who need to complete all prerequisites before the MCAT.

FAQ

How hard is a biology degree compared to other science majors?

Biology is considered moderately difficult among STEM majors. The chemistry and physics prerequisites are challenging, and the volume of material is substantial, but the math requirements are less intensive than physics, engineering, or mathematics degrees. The primary challenge is time management — balancing multiple lab courses with their associated reports and exams requires consistent daily effort.

Can I become a doctor with a biology degree?

A biology degree is the most common major among medical school applicants, but it is not required. Medical schools require specific prerequisite courses (general chemistry, organic chemistry, biochemistry, physics, biology, English, and statistics) regardless of your major. The BS in Biology covers most of these prerequisites automatically. For more on medical career paths, see the biology careers page.

How long does it take to complete a biology degree?

Four years of full-time study is standard (120 credit hours). Falling behind in the prerequisite sequence can add a semester. Students pursuing pre-med, pre-dental, or pre-veterinary tracks on top of the biology major occasionally need an additional semester if they also want research experience and clinical volunteering on their resume.

What math does a biology degree require?

Most programs require at least Calculus I and one or two semesters of statistics. Some programs require Calculus II. Physics courses (also required) assume calculus competency. The day-to-day math in biology courses involves algebra, ratios, and statistical analysis rather than advanced calculus. If you enter college needing pre-calculus, plan your schedule carefully to stay on sequence.

Can I transfer from community college into a biology program?

Yes, and this is a common and cost-effective path. Complete your general education requirements, general chemistry sequence, and ideally General Biology I and II at community college. Verify that your courses transfer as equivalents — especially the lab components. See our community college transfer guide for detailed steps.

What is the difference between a biology degree and a biomedical science degree?

Biology is broader, covering ecology, evolution, plant biology, and organismal diversity alongside molecular and cellular topics. Biomedical science focuses specifically on human health, disease, and medical applications. Both prepare you for medical school, but biology gives you more flexibility for non-medical careers while biomedical science is more narrowly focused on clinical and pharmaceutical paths.

More on this degree:

• Biology Degree Guide — Overview
• Is It Worth It?
• Career Paths
• Salary Data
• How Hard Is It?
• Internships
• Best Colleges