The College of Biological Sciences is revamping core biology at UC Davis to enhance STEM curricula. Replacing BIS 2A, 2B, and 2C, the BIO123 Series focuses on adaptation, heredity, ecology, evolution (BIO1); metabolism, DNA structure, and cell biology (BIO2); and challenges of multicellular life with evolved adaptations (BIO3). Optional labs BIO1L and BIO2L, now separate, emphasize inquiry-based approaches and multi-week projects for hands-on experience in biological techniques and hypothesis testing.
What's Changing
The BIO123 Series curriculum is designed to enhance student learning through an integrated and conceptual approach. The updated structure emphasizes hands-on experiences, problem-solving, and real-world applications, fostering deeper engagement with the life sciences. Some of the most notable changes include:
BIO123 Lectures
- Creation of a sequenced, 12-unit lecture series:
- Each course has 3 hours of lecture with a small (24-person) discussion section to support student learning.
Sequencing of the courses will allow for improved student success as study skills and topics mastered in one course can be built on in subsequent courses. Topical themes can be connected and reinforced across the sequence, connecting to practical problems such as climate change, human health, and biodiversity conservation and ecosystem management.
BIO 1L and 2L
- Creation of a sequenced lab series that can be taken concurrently with BIO1 and BIO2 (2 additional units):
- These courses have hands-on, hypothesis-driven, inquiry-based laboratory activities that meet 2.5 hours/week.
- Their goal is to grow a student’s scientific mindset and build a more intuitive understanding of the molecular and biological world, and to enhance their ability to formulate and test hypotheses using current techniques in molecular and cellular biology, ecology, evolution and biodiversity.
Recommendation for Majors Requiring BIS2ABC
For majors that require a full year of introductory biology, we recommend that students take all five courses in the BIO123 Series, including BIO1, 2, 3 and both BIO1L and 2L, totaling 14 units. Alternatively, the new structure allows departments to require the BIO1, 2, and 3 lecture courses without the BIO1L and 2L lab courses, affording two units of flexibility for major-specific instruction.
BIO123 Series Rollout Timeline
As UC Davis begins rolling out the new BIO123 Series in Fall 2025, starting with BIO1 and 1L, the current BIS2 series (BIS2A, BIS2B, BIS2C) will continue to be offered every quarter during the 25-26 Academic Year (Fall, Winter, and Spring).
Replacing BIS2ABC Courses with BIO123 Courses and Labs
The introduction of the BIO123 Series will result in the eventual cancellation of courses in the BIS2 series. If you currently require BIS2A, B or C in your major's curriculum, or as a prerequisite for one of your courses, please use the collected BIS2ABC syllabi to familiarize yourself with their content.
Currently, there are five scenarios where BIS2 courses represent instances where the change to the BIO123 Series will require substitutions to fulfill the prerequisite or major requirements:
- If only BIS2A is required
If only BIS2A is required, we recommend one of the following two options:
Take BIO2 lecture (4 units). If lab component is desired, add BIO2L (1 unit). Note that BIO2 has a prerequisite of BIO1 (4 units). BIO2L has a prerequisite of BIO1L (1 unit).
ORTake BIS 010 – Everyday Biology (4 units). Example BIS 010 syllabus.
- If only BIS2B is required
If only BIS2B is required, we recommend the following replacements:
Take BIO1 lecture (4 units). If lab component is desired, add BIO1L.
- If both BIS2A & BIS2B are required
If both BIS2A and BIS2B are required, we recommend the following replacements:
Take BIO1 lecture (4 units) and BIO2 lecture (4 units).
If lab component is desired, take BIO1L (1 unit), and BIO2L (1 units). Note that BIO1L is required for BIO2L.
- If both BIS2B & BIS2C are required
If both BIS2B and BIS2C are required, we recommend the following replacements:
To replace BIS2B, Take BIO1 (and 1L if lab desired).
To replace BIS2C, take either BIO3 or BIS70 or other non-CBS courses to be listed here as they are identified. Note that if BIO3 option is selected, BIO1 and BIO2 will also be required since they are prerequisites.
Syllabi of Potential Replacement Courses*
*This folder is populated with options within CBS, such as the new courses and labs in the BIO123 Series, as well as other CBS-administered courses, like BIS10 and BIS70. As various departments identify substitutions, we will update the pages above to include their recommendations.
How Do I Add BIO123 Courses as Prerequisites Using ICMS?
Overview
Instructors should add the new BIO123 courses as options rather than replacing existing BIS2 prerequisites. For example, if a course requires BIS2B, add BIO1 as an option so that the catalogue reads "BIS2B or BIO1." This will accommodate students who have taken courses in either series. You can do this yourself if you have ICMS access. If you do not have ICMS access, you will need to contact your department's instructional support staff.
Getting Started
To add the new BIO courses as a prerequisite from an existing course, submit a Prerequisite/Restrictions ICMS proposal. If this is the only change to be made, make sure to use this proposal type for a quicker processing time.
Course Information Tab
You will need to enter the effective term for the change and fill in the remarks box. A sample for BIS 101 is below.
Prerequisites Tab
To add the appropriate BIO123 Series course(s) as prerequisites takes two steps. First, you will need to remove the existing BIS2 series course(s) from the prerequisite list, then re-enter it with the condition “or.” Second, you will add the new BIO123 Series course(s).
You can see a sample from BIS 101 below. Note the logic: ((BIS002A C- or better) or (BIO002 C- or better))
At the bottom of this page, make sure to review the Prerequisite Catalog View box to make sure it reads correctly. This is what students and advisors will see. See BIS 101’s sample below.
Approvals
The department and college course committees will review and, if approved, the proposal will go directly to the team that adds to the catalog course list.
Additional FAQs
- Why are we making these changes now?
- The new course series enhances small-group discussions, hands-on labs, and active learning to better prepare students for upper-division coursework. By focusing on core concepts and practical skills, the updated series allows for greater mastery and retention while maintaining a strong foundation in biological sciences.
- How does the structure of the BIO123 Series compare to that of the BIS2ABC series?
- The new BIO123 Series must be taken in sequence and separates lectures and labs into standalone courses (e.g., BIO1 and 1L). Lecture courses are now 4 units (3 units of lecture, 1 unit of discussion), while labs are optional 1-unit courses which can be taken concurrently with the lectures. This structure facilitates small-group discussions, active learning, and scheduling flexibility while reducing the overall series by 1 unit.
- What about BIS2C, Introduction to Biology: Biodiversity and the Tree of Life?
- Key topics from BIS2C are distributed across the series. BIO1 covers the basics of phylogenies and major evolutionary innovations. BIO2 addresses the evolution of unicellular life and distinctions among bacteria, archaea, and eukarya. BIO3 highlights functional biology and adaptations in multicellular organisms (plants and animals) without systematically covering all organismal diversity. A broad survey of the diversity of life will still be available in the new 3-unit BIS 070 lecture course (Biodiversity and the Tree of Life), which will be offered after BIS2C is discontinued.
- How do I know if a course has BIS2A, BIS2B or BIS2C as a prerequisite?
- To see if a BIS2 series course is a prerequisite for one of your courses, review the ICMS impact report for each respective course. This report will also indicate which majors and minors have these courses listed under program requirements.
BIS02A Impact Report
BIS02B Impact Report
BIS02C Impact Report - How will these changes influence prerequisites for upper-division courses?
- Departments will determine which of BIO1, BIO2, or BIO3 align with their course prerequisites. For courses that previously required BIS2ABC or a full-year biology introduction, the BIO123 Series is recommended. Departments looking for broader coverage of organismal diversity across all life should consider requiring BIO70.
- How will the new series articulate with community college biology courses?
- In the short term, community college courses will continue to articulate into the BIS2ABC series. Over the next two years, CBS will work with community colleges to develop new articulation agreements for the BIO123 Series. In the longer term, the BIO123 Series is expected to articulate more easily with most community college courses than the current BIS2ABC series.