Advice for Students Interested in Pursuing the Major

There is no longer an admission process to declare Biology as a major. We do recommend that students complete at least one introductory biology course (Biol 161, Biol 162 or Biol 163) before declaring Biology as a major.

Prospective majors with questions should contact Professor Julia Paxson for advising. The department holds open advising sessions each semester and provides additional detailed information about the major on its website. 

Requirements for Bio Majors 

Major requirements

Course Number(s)

Three course Introduction to Biology Sequence

BIOL 161 , BIOL 162 and BIOL 163.

Five other upper division biology courses, at least three of which must have accompanying labs

Courses must include at least one from three of the four Course Distribution Areas

  • Cellular and Molecular Biology (BIOL 241, 261, 262, 266, 269, 301, 302, 310, 362, 392)
  • Organismal Biology (BIOL 211, 212, 213, 214, 220, 223, 230, 232, 250, 285, 390, 391)
  • Ecology and Evolution (BIOL 233, 235, 280, 281, 283, 287, 331, 381, 383)

Two chemistry courses

CHEM 181 plus either CHEM 221 or CHEM 231 (all with labs)

Calculus 1 (or the equivalent)

MATH 135 or equivalent

An approved Holy Cross course in statistics

BIOL 275 or STAT 220

Two additional cognate courses chosen from the approved list maintained by the department




AP or IB credits may not be used to fulfill this requirement.


CHEM 221, CHEM 222, CHEM 231, CSCI 131, CSCI 132, CSCI 135, GEOS 150, GEOS 210, GEOS 270, GEOS 310, GEOS 350, MATH 136, MATH 241, PHYS 115, PHYS 116, PSYC 221.


Students may elect to substitute an upper division biology course (beyond the required five) for one of these cognates

Please note:  Anatomy and Physiology 1 and 2 can now be counted towards the Biology major as Intermediate level courses with labs under the Organismal Biology distribution area.

One semester of research for credit may be used toward the upper division biology course requirement with lab. Students may substitute one geoscience course above the 100 level for an upper division biology course. Of the minimum total of eight biology courses required by this curriculum, at least six must be taken at Holy Cross.

Additional Notes

  • Minor: A minor in geosciences, open to students of any major, is now available. Visit the geosciences website or contact Prof. Sara Mitchell for more information.
  • Department honors: No
  • AP credit: Majors with AP scores in biology do not receive credit toward the minimum number of required major courses nor do they receive advanced standing. Non-major students with AP Biology scores of 4 or 5 receive natural science common credit.