Requirements For the Biology Major

Welcome to an overview of the biology department curriculum. This page is intended primarily for students who are, or who wish to become, biology majors. 

If you are a pre-health profession student who is not and does not wish to become a biology major, please follow this link for advice about your curriculum.

Quick Links





General Advice: Successul completion of the biology major requires thoughtful planning. Consult with a faculty member in the Biology Department as soon as possible, even if your formal advisor is in another department.  Begin your chemistry and biology courses as soon as possible -- it is especially advisable to start chemistry your first semester.

Accesss to courses and admission to the biology major.  Incoming students must complete at least one introductory biology course that is intended for majors plus one approved course in either chemistry (CHEM 181 or more advanced) or physics (PHYS 111 or 115 or more advanced) before applying to the biology major.  These courses must be taken at Holy Cross; transfer stiudents may apply for a waiver.  Additional information about admission to the major

Introductory Biology Sequence:  An introductory biology sequence of three courses is designed to give all students a complete background in the methods, ideas and concepts of three major approaches to biology.  This sequence should be completed early in a student's college career, normally by the end of the sophomore year.

Biology 161 and 162 are opened to all students interested in the biology major, prehealth students from other majors, and environmental studies majors. 

Biology 163 is opened to all but is normally taken only by biology majors and environmental studies majors and concentrators.

Biology majors will take:

  • Biology 161 (Introduction to Cellular and Molecular Biology). This course introduces students to biology of the microscopic and molecular realms.  Topics include biological molecules, chemical reactions, especially those catalyzed by enzymes, biological pathways, energy metabolism and photosynthesis, prokaryotic and eukaryotic cell structure, signaling, recognition, and molecular genetics. Although the approach is strongly mechanistic, much of the subject matter is viewed through the lens of evolution. Taught annually in both the fall and spring semesters.
  • Biology 162 (Introduction to Mechanisms of Multicellular Life).  Organization above the cell up to the whole organism is the focus of this course. The approach is mechanistic but the evolution of these processes is also a major theme. Vertebrates, especially mammals, and flowering plants are used as model organisms to understand the basic features of reproduction, transmission genetics, development, coordination, and organism-level transport, metabolism, fluid and solute regulation, support and movement. Taught annually in both the fall and spring semesters.
  • Biology 163 (Introduction to Biological Diversity and Ecology). This course provides an introduction to the core concepts of ecology an overview of evolution and biological diversity, primarily in multicellular organisms.  Taught annually in both the fall and spring semesters.

Most students should take courses in the order Biology 161 -> 162 -> 163.  Students with strong environmental interests may want to use the sequence Biology 163 -> 161 -> 162. 

Pre-health professional students who are not biology majors should take Biology 161 followed by 162. 

Tracks:  By the end of the second year, biology majors must elect one of two tracks. The tracks were established in recognition that different areas of biology require somewhat different training.  The cellular and molecular biology track (CMB) emphasizes structures and biochemical processes common to all organisms. The ecological, evolutionary and organismal track (EEOB) examines more complex levels of organization -- the function and diversity of organisms and populations, how populations evolve, and the interactions between organisms and their environment.

Links to detailed track information:

Both of the pages above have links to models for course selections for students with different interests and backgrounds and links to course descriptions and concentrations of interest to students in a particular track.   


Go to the top of this page