2026-2027 Catalog

Advising Information

Students interested in Biology are encouraged to complete the introductory sequence in their first year (BIO105 or BIO110 and BIO130). It is also helpful to complete Calculus I during the first year.

Placement Information

IB or A-level examinations in Biology will not substitute for an Occidental course or place students into advanced courses.


Most students who are interested in majoring in Biology should take the Calculus Placement Assessment (ALEKS) during the summer prior to their first year. You do not need to take the Calculus Placement Assessment if any of the following are true:

  • You received a score of 4 or 5 on either the AP Calculus AB or BC exam;
  • You received an IB Calculus HL score of 5 or above;
  • You have already taken a Calculus 1 course at another accredited college or university.

Curricular Notes

  • All Biology majors start with the same group of gateway courses; Marine Biology (BIO105) OR Intro Biology: Biodiversity, Ecology, and Evolution (BIO110), AND Intro Biology: Cellular and Molecular Biology (BIO130).
  • Foundations of General Chemistry (CHEM120 or CHEM 130) is a pre-req for BIO130, though it is also possible to take the CHEM and BIO courses concurrently.
  • Senior Seminar and two 300-level Biology courses with labs that count for the second stage writing requirement must be completed at Occidental.
  • Directed Research (BIO193/293) is a valuable experience. Students can also pursue research over the summer as part of the URC SRP; students who have had previous research experience are stronger applicants to this program. Students might also consider pursuing summer research opportunities at other institutions.

Sample 4-Year Plan

The 4-year plan below is one pathway through the major.



Fall

Spring

Year 1

Fall FYS course

BIO105/BIO110 (CPLS)

CHEM120

Core Req

Spring FYS course

BIO130 (CPLS)

Calc I

Core Req

Year 2

200-level Bio Req

CHEM220

Core Req

Core Req

BIO268 Biostats

200-level Bio Req

Core Req

Core Req

Year 3

200-level Bio Req

Quant Literacy Req

General Elective

General Elective

200-level Bio Req

300-level Bio Req

General Elective

General Elective

Year 4

BIO490 or 300-level

300-level Bio Req

General Elective

General Elective

BIO490 or 300-level

General Elective

General Elective

General Elective

Biology Transfer Student Advice

Transfer students should contact the Biology department chair two weeks before registration for transfer-specific advising information.

Transfer students should come in having met as many Core requirements as possible.

Designated Transfer Adviser

Graduate Study

Graduate study toward the degree of Master of Arts under the thesis plan may be undertaken in Biology by properly qualified students. Thesis projects may be selected in any of the following fields: cellular biology, developmental biology, immunology, microbiology, molecular biology, neurobiology, biochemistry, comparative physiology, animal behavior, environmental biology, ecology, systematics and evolutionary biology, and marine biology. Graduate courses, numbered 500 and above, are valued at five units unless otherwise noted. Consult the department chair for further information on graduate studies.