BA in Biology

The Biology major provides students with a breadth of understanding across the full range of biological disciplines as well as an opportunity to explore one of several specialized areas in greater depth. Required coursework for the major and different specializations establishes a core of fundamental knowledge in biology and related sciences. Students build on this foundation through a variety of lecture, laboratory, field, and seminar courses that offer them the opportunity to focus on specific disciplines. The development of laboratory and field skills is encouraged through elective participation in the cutting-edge research of the department’s faculty and engagement in the extensive biological resources in the Boston area. Students graduate with the skills and intellectual base for employment in the burgeoning life sciences job market or for further education, including both graduate programs and professional schools.


All students entering as freshmen in Fall 2018 and after will pursue coursework in the BU Hub, a general education program that is integrated into the entire undergraduate experience. BU Hub requirements are flexible and can be satisfied in many different ways, through coursework in and beyond the major and, in some cases, through co-curricular activities. Students majoring in Biology will ordinarily, through coursework in the major, satisfy BU Hub requirements in Scientific Inquiry and Quantitative Reasoning, as well as some of the requirements in the Intellectual Toolkit. Through Biology breadth and elective courses, students may also satisfy some of the requirements in Communication and Diversity, Civic Engagement, and Global Citizenship. Remaining BU Hub requirements will be satisfied by selecting from a wide range of available courses outside the major or, in some cases, co-curricular experiences.

The Biology major requires a total of nine courses in biology (introductory, breadth, and elective courses) and a total of six to seven related courses in chemistry, math/computer science, and physics.

Excluding Introductory Biology courses (CAS BI 107 and BI 108 or equivalents):

  • at least three biology courses must have a laboratory component
  • at least three biology courses must be at the 300+ level
  • at least five biology courses must be taken in the BU Biology Department (or be cross-listed with BI courses in CAS or MET)

Biology course requirements can overlap (e.g., BI 315 simultaneously counts as a breadth requirement, as a lab course, and as a 300+ level course. Nonetheless, BI 315 is only counted as a single course toward fulfillment of the major).

A grade of C or higher is required for major credit in all courses (except corequisite chemistry courses). A grade of C– or higher is required for major credit in corequisite chemistry courses.

Course titles and full descriptions are located in the Courses portion of this Bulletin. Unless otherwise noted, all required courses are 4 credit hours.

Introductory Biology (2 courses)

  • CAS BI 107 (or CGS NS 201)
  • CAS BI 108 (or BI 116)

Breadth Requirement (3 courses)

Choose one course in each of the following three areas:

Cell & Molecular Biology (CM)

  • CAS BI 203 (or BI 213 or BI 218*) or
  • CAS BI 206 (or BI 216)

Physiology and Neurobiology (PN)

  • CAS BI 315* or
  • CAS BI 325 (or NE 203*)

Ecology, Behavior, Evolution (EBE)

  • CAS BI 225 or
  • CAS BI 260 or
  • CAS BI 303* or
  • CAS BI 306* or
  • CAS BI 309 or
  • CAS BI 407*

*Course will also count toward the three lab requirement.

Biology Electives (4 courses)

^ These electives can be any 4-credit courses offered by the Biology Department, including CAS BB 522 and/or eligible courses under the Optional Programs section of this Bulletin page. Please note the following exceptions (which cannot be used toward the major):

  • CAS/MET BI 105
  • CAS/MET BI 106
  • CAS BI 114
  • CAS BI 119
  • CAS BI 194
  • CAS BI 196
  • CAS/MET BI 210
  • CAS/MET BI 211

Note: After introductory biology, a minimum of five courses must be taken in the BU Biology department (i.e., have a CAS or MET BI or BI cross-listed course designation). A maximum of four MET courses may be counted as credit toward the BA degree. In addition, at least three courses must be at the 300+ level and three must have a laboratory component. Some of these requirements can overlap (e.g., BI 315 simultaneously counts as a breadth requirement, a 300+ level course, and as a lab toward the three-lab requirement). Nonetheless, it is counted only as a single course toward fulfillment of the major.

Related Requirements (6–7 courses)


Choose one of the following tracks (in consultation with your major advisor):

Standard Track (recommended):
  • Choose one of the following general chemistry sequences:
Sequence I Sequence II Sequence III
CAS CH 101 &
CAS CH 102 (or CH 116)
CAS CH 109 &
CAS CH 110
CAS CH 111 &
CAS CH 112


  • Choose one of the following organic chemistry courses: CAS CH 203 (or CH 211 or CH 218)
Alternative Track (not acceptable for most pre-health careers):
  • CAS CH 171^

^ Or any completed general chemistry sequence from the standard track


  • CAS CH 172 or CH 174

Note: It is recommended that the standard track general chemistry sequence (or alternative track’s CH 171 & 172 or CH 171 & 174) be taken concurrently with BI 107 and BI 108 during freshman year. Most Biology majors complete the standard track and continue onto a fourth semester of chemistry (CH 204 or 214), which is a requirement for medical and other professional schools. Students intending to apply to medical school are also advised to take biochemistry (CAS BI 421/422 or CH 373) in their junior or senior year.

Mathematics/Computer Science

Choose a total of two courses from the lists below. At least one course must be calculus or statistics:

Calculus Courses:
  • CAS MA 121
  • CAS MA 122
  • CAS MA 123
  • CAS MA 124
  • CAS MA 127
  • CAS MA 129
  • CAS MA 196

Note: Students cannot take more than one of the following for credit: CAS MA 121 or 123; similarly, students cannot take more than one of the following for credit: CAS MA 122, 124, 127, or 129.

Statistics Courses:
  • CAS MA 115
  • CAS MA 116
  • CAS MA 213
  • CAS MA 214

Note: MA 113 will not satisfy major requirements. Students cannot take more than one of the following for credit: CAS MA 113, 115, or 213; similarly, students cannot take more than one of the following for credit: CAS MA 116 or 214.

Computer Science Courses:
  • CAS CS 105
  • CAS CS 108
  • CAS CS 111


Choose one of the following sequences:

  • CAS PY 105 & 106 or
  • CAS PY 211 & 106 or
  • CAS PY 211 & 212 or
  • CAS PY 241 & 242

Optional Programs

Non-Departmental Courses

A maximum of two approved courses outside the Biology Department may count as Biology electives. Approved courses are listed below. None of these courses count toward the three lab requirement.

  • CAS CH 373
  • CAS PS 338
  • GMS BT 404
  • GMS BT 426
  • GMS BT 432
  • GMS BT 456
  • GMS BT 465
  • SAR HS 251
  • SAR HS 360
  • SAR HS 369
  • SAR HS 370

^ Course will also count toward the three lab requirement and is not considered an outside course.

Marine Semester (MS)

The Marine Semester provides hands-on laboratory and field experience both on campus in our Marine Research Teaching Lab and off campus at field sites in New England and Belize in Central America. The program is offered in the fall semester. Students must meet the prerequisites for the program and apply through the BU Marine Program (BUMP) website. They then select one course during each of four “blocks.” Each block comprises 18–20 class days. All Marine Semester BI-coded courses count as Biology electives and toward the requirement for three lab courses.

Please visit the BUMP website for prerequisites, additional information, and to apply to the Marine Semester. For an updated list of Marine Semester courses, see the Marine Science Bulletin page.

Tropical Ecology Program (TEP)

The Ecuador Tropical Ecology Program offers Biology students the opportunity to participate in intensive, field-based scientific investigation of Ecuador’s vast and diverse ecosystems, from the Amazon basin to the Galápagos Islands. The program is offered in the fall and spring semesters. Students must meet the prerequisites for the program and apply on the Study Abroad TEP webpage. The program features four ecology courses based on field research. All the TEP courses count as Biology electives and satisfy the requirement for three lab courses.


Please visit the Study Abroad webpage for prerequisites and additional information.

Undergraduate Research in Biology

While research is not required by the major, undergrads are encouraged to participate in research during their time at Boston University. Undergraduate research courses are available at all levels and require students to submit an application and receive approval by the Director of Undergraduate Studies.

Freshman BI 191/192 2 credits
Sophomore BI 291/292 2 credits
Junior BI 391/392 2 or 4 credits
Senior BI 491/492 4 credits

Notes: Up to two 4-credit semesters can be used to fulfill major electives (these semesters do not need to be taken consecutively). One of these two semesters can be used toward the three lab requirement. Both 2- and 4-credit research count toward graduation credits.

Seniors may pursue Honors Research in Biology; see information below.

Please visit the Biology Department website for additional information regarding Undergraduate Research in Biology.

Modular Medical Integrated Curriculum (MMEDIC) Program

Juniors and seniors who have been admitted to the Modular Medical Integrated Curriculum (MMEDIC) program, with the appropriate prerequisites and approval from the director of the MMEDIC program, may register for certain courses that have been developed for this program. The MMEDIC program offers an integrated curriculum composed of undergraduate and medical school-related courses that facilitate the transition to the curriculum at the School of Medicine. Those interested in early admission to the Boston University School of Medicine through the MMEDIC program should apply through the Pre-Professional Advising office (100 Bay State Road, 4th Floor) at the beginning of the second semester of their sophomore year.

The following courses may count toward the biology major for students enrolled in the MMEDIC program:

  • GMS AN 722 Cellular Organization of Tissues (4 cr)
  • GMS BI 751 Biochemistry and Cell Biology (6 cr)
  • GMS MI 713 Comprehensive Immunology (4 cr)
  • GMS PH 730 Human Physiology A (4 cr)
  • GMS PH 731 Human Physiology B (4 cr)

Note: Students enrolled in the MMEDIC program may petition for up to three MMEDIC courses to be accepted toward the biology major. MMEDIC students must take a minimum of four non-MMEDIC courses beyond the introductory level in the Department of Biology in order to fulfill the department’s residency requirement.

Additional Information

Please see the Department of Biology portion of this Bulletin for information on the following topics:

  • Advanced Credit (AP & IB Exams)
  • Department Residency Requirement
  • Intercollege Cross-Registration
  • Premedical Students
  • Study Abroad Programs

Honors in the Major

Honors Research in Biology requires senior standing and an overall GPA of 3.5. Students complete two semesters of 4-credit research (CAS BI 401 & 402) and one semester of the Honors Seminar (CAS BI 497 or 498). In addition, Honors students must complete and defend a written senior thesis.