Please find below some sample pathways through the Biology Major and also some Biology Major samples.

 There are several ways to navigate the Introductory math and science courses necessary for the foundation of a Biology major. Consider your Amherst College Math/Chemistry placements, your previous preparation in Biology, whether you are interested in other related majors and/or the pre-medical curriculum (see the relevant web sites for requirements), and also consider your extracurricular interests since these may affect whether you have the time to commit to two lab courses in the same semester (all introductory chemistry and introductory biology courses are lab courses).

In consultation with your advisor, you should tailor your own path to give you the best opportunity for success in these courses so that you can move on to advanced courses with confidence.

*See also: Biology Major Requirements

The image below of 9 sample pathways is to help you to understand that there are many ways to begin the Biology major:

Biology Major Pathways (click to expand the image!)

(a PDF file of these sample pathways is available for download at the bottom of this webpage.)

Biology Major Samples (click to expand the image!)

(a PDF file of these sample pathways is available for download at the bottom of this webpage.)

Specific Notes:

  • Pre-med students are recommended to take BIOL-181 and BIOL-191 as their two Biology laboratory courses. Both introductory laboratory courses provide solid understanding the important ecological, evolutionary, organismal, cellular, molecular and biochemical foundations necessary for the pre-health track.
  • Since MATH-121 is not a required prerequisite for any Biology course, so is not listed in these paths.
  • Biology, Chemistry, and Math Departments agree that it is NOT in a student’s best interest to take more than two STEM courses in the fall of the first year; instead, chose 1-2 to fit your own preparation and future plans.

  • Note that unlike Chemistry and Math courses, the introductory Biology courses can be taken in either order. They each serve as a pre-requisite for different advanced Biology courses (consult course description); courses that require BIOL-191 also require a year of intro Chemistry (since this is required for BIOL-191).

  • BIOL-191 requires completion of, or concurrent enrollment in, CHEM-161/165.

  • CHEM-161/165 requires completion of CHEM-151/155 or the equivalent, and CHEM-151 requires completion of MATH-111 or MATH-105/106 and CHEM-155 requires MATH-121 or equivalent (eg. AP credit that places you into MATH-121 OR 211).

  • BIOL-181 is offered every fall semester and BIOL-191 is offered both fall and spring semesters.

  • Most advanced Biology courses are not open to first year students (consult course description).

  • Students who are following a pre-med curriculum are recommended to begin with chemistry; BIOL-181 and BIOL-191 are recommended as the two Biology laboratory courses; check with the health professions advisors for other specific recommendations.

  • Other majors that overlap with the Biology major are Environmental Studies, Biochemistry & Biophysics, and Neuroscience; consult web sites for these majors to learn of their course requirements.

 Key Table of prerequisites for Intro courses:

Department & Course Course Type and when offered Pre-requisites

BIOL-181: Adaptation and the Organism

This a prerequisite for courses such as Ecology, Evolution, Animal Behavior, and Disease Ecology


Fall only

No pre-requisites

BIOL-191: Molecules, Genes and Cells

This a prerequisite for courses such as Molecular Genetics, Cell Biology, Development, Microbiology, Biochemistry, and Neuroscience


Fall & Spring

Completion of
or co-enrollment in CHEM-161/165

CHEM-151: Introductory Chemistry


CHEM-155: Fundamental Chem Principles

Lect/Lab/Disc Fall & Spring

Lect/Lab/Disc Fall only

Placement by Chem Dept

CHEM-155 requires placement or enrolment in MATH-121

CHEM-161: Chemical Principles


CHEM-165: Foundations of Thermodynamics & Kinetics


Fall & Spring

Completion of CHEM-151
and MATH 111/105-6

Completion of CHEM-155
and MATH 121

MATH-105 Calculus with Algebra & MATH-106


MATH-111: Intro to the Calculus

Lect/Disc Fall, Spring

Lect/Disc Fall & Spring

Placement by Math Dept