Science Division

Molecular, Cell & Developmental Biology

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Enrollment Guide

MCD Biology Enrollment Guide for Winter 2026!

Updated 11/6/2025

This Enrollment Guide contains important information and updates about enrolling in classes for Winter Quarter 2026.

If you have concerns about housing insecurity, please contact Slug Support. If you are having trouble finding housing, please contact the UCSC Housing Office.

Winter Curtailment 2025-2026

Winter Curtailment is the period of time between the Fall and Winter quarters where campus is closed outside of emergency services. UCSC and the UC Office of the President have realigned the 2025-2026 Winter Curtailment dates for this upcoming Winter meaning that UCSC offices and campus as a whole will be closed from Monday, December 22nd, 2025 to Monday, January 5th, 2026. These dates have been posted to the Academic and Administrative Calendar under the Key Dates and Winter Holidays. 

Please note that Monday, January 5, 2026 is the first day of instruction for the Winter 2026 quarter. 

If you need any advising assistance, please be sure to reach out to advising offices well before Friday, December 19, 2025 to ensure we are able to respond before the campus approved Winter Curtailment dates. We may be able to respond to some emails, however, please note that our responses may be delayed during the curtailment period.

Helpful Reminders:

  • Prioritize your major courses during First Pass enrollment and add GE’s during Second Pass enrollment, if necessary. 
  • Waitlists can only be joined during SECOND pass. 
  • Ensure you have no holds on your enrollment by checking your MyUCSC Student Center well before your enrollment appointment. 
  • Need to repeat a class for the third time? Be sure to check in with your College regarding a Double Repeat/Triple Take petition! NOTE: You MUST meet with your College to gain access to the Double Repeat/Triple Take petition.

Winter Enrollment Schedule (At-a-Glance): 

Table of Contents:

Winter 2026 Enrollment Resources 

How to Get Support During Enrollment

Be sure to check your UCSC.EDU email! All students Proposed or Declared an MCD Biology Department Sponsored Major (Biology, BS; MCD Biology, BS; and Neuroscience, BS) should have received an email from one of the MCD Biology Advisors inviting you to schedule a 15 minute Enrollment Check Appointment. These appointments are not mandatory, however, if you have any enrollment questions for the Winter 2026 quarter, be sure to schedule an appointment via that message. 

If you cannot schedule an appointment or do not wish to schedule an appointment, additional resources are available, the resources are listed below:

What Should I Enroll In?

Transfer Students

Incoming Winter 2026 Transfer Students:

If you have completed CHEM 8B Organic Chemistry → Enroll in BIOL 100 Biochemistry. You can pair it with any lower division course you would like (e.g.,  MATH 11B/19B, STAT 5 or 7/L, or PHYS 6A). 

*Note: BIOL 100 is the main prerequisite for most upper division MCD Biology (BIOL) courses and should be completed as soon as possible after transferring to UCSC.

If you have not completed CHEM 8B – look to enroll in BIOE 107: Ecology (for Biology, BS majors) or BIOL 105 Genetics and CHEM 8B Organic Chemistry.

Continuing Fall 2025 Transfer Students:

If you have not completed CHEM 8B Organic Chemistry be sure to enroll in Winter 2026 – delaying CHEM 8B may delay your graduation as CHEM 8B is a prerequisite for BIOL 100. 

*Note: BIOL 100 is the main prerequisite for most upper division MCD Biology (BIOL) courses and should be completed as soon as possible after transferring to UCSC.

Other courses you can consider completing if you have not completed them already: 

  • any lower division course you have not already completed
    • For Example: MATH 11B, STAT 5 or 7/L, or PHYS 6A or PHYS 6B or PHYS 6C)
  • BIOL 105 or BIOL 100
  • BIOL 101 (if BIOL 100 is in-progress for Fall 2025)
  • BIOE 109 (prerequisite: BIOL 105)
    • UD Elective for MCD Bio BS, Core course for Biology, BS 
  • Upper Division (UD) Electives if prerequisites have been completed. 

You can declare your major right now via your MyUCSC Student Portal – Instructions available HERE.

If you find any discrepancies in your Degree Progress Report (DPR) regarding your Transfer credit; please consult your “Transfer Credit: Report ” in MyUCSC for accurate transfer information and speak with an MCD Biology Advisor.

Frosh Students

Continuing Fall 2025 Frosh

Continue your General Chemistry Series with the aim of completing CHEM 3A, CHEM 3B (and CHEM 3BL), and CHEM 3C (and CHEM 3CL) by the end of Spring 2026 (Fall 2026 at the very latest!). 

If you were not able to enroll in CHEM 3A for the Fall 2025 quarter, that is ok! Be sure to enroll in CHEM 3A for Winter 2026 to remain on-track with completing the MCD Biology Major Qualification Requirements by the end of your 5th quarter at UCSC.

REMEMBER: The MCD Biology Department has a Qualification Policy that requires students looking to declare an MCD Biology Department Sponsored major to complete all 8 Qualification courses by the end of their 5th quarter at UCSC (summer is not included in the quarter count) with C or better letter grades. If you started at UCSC in Fall 2025, your 5th quarter at UCSC is Winter 2027!

Please remember that BIOL 20A has a prerequisite of CHEM 3A and BIOE 20B/BIOL 20L have a BIOL 20A prerequisite.

Full/Closed Class – What Should I Do? 

Always prioritize qualification courses or the Core Upper Division (BIOL 100, 101, and 105; BIOL 110 and BIOL 120 for MCD Biology, BS majors) courses during first pass enrollment. We try to hold some seats in courses until after second pass enrollment, but we cannot guarantee additional seats will be available.

The ONLY WAY to request a seat in a course that is FULL is to get on a waitlist during second pass enrollment. A spot on the waitlist does not guarantee a spot in the class, so make sure you have a back up plan.

Please be sure to also read the course notes/enrollment restrictions for courses. Most enrollment restrictions lift during or after Second Pass Enrollment.

If you are not able to enroll or waitlist during your Second Pass enrollment appointments, it may be because:

  1. You are missing a prerequisite
  2. You have an enrollment hold (check your portal for details)
  3. You have exceeded the number of units you are allowed to enroll in or waitlist

If you were unable to waitlist or add a class from your portal due to an enrollment restriction on the course (i.e. not being a declared MCD Biology major), you can complete the Enrollment Request Form for Winter 2026 a few weeks before the First Day of Instruction on Monday, December 15th, 2025.

*Note: The Enrollment Request Form does not override holds or prerequisites. 

The reason we wait to open the form is because many enrollment problems/challenges that students are encountering right now will be resolved well in advance of the first day of class or they may decide that they are no longer interested in taking the class.

Though the MCD Biology Department does try to hold a few seats in a class, once the class is full/reaches capacity, no additional seats will be available. Generally, by the end of the first week of instruction, all seats available in a course are opened or the course is fully enrolled.

Please remember that the MCD Biology Department strictly enforces course prerequisites – the Enrollment Request Sheet does not override course prerequisites.

Academic Planning

MCD Biology Curriculum Plan 2025-2026

Visit the MCD Biology Department Curriculum Plan page to help you plan your courses for the rest of the year. Please remember that the curriculum plan is subject to change.

Note that other departments have these too:

Need a Second or Third Class? 

Be sure to meet with your College Advisor to check your General Education (GE) requirements as well as other University requirements are met. The Colleges have provided a list of courses that have few (if any) prerequisites – this list is called the “Best Bets List”. If you have questions regarding the Best Bets list, please contact your College Advisor.

Remember! You have at least 2 Advisors at UCSC! MCD Biology Undergraduate Advising is your Major advising home; your College Advisors are your General Education and University Requirement advisors – they also have resources to help you be successful during your time at UCSC.

Need to Make a Plan for Yourself? 

Need help with creating an Academic Plan? Schedule an appointment or attend Drop-in with our Peer Advisors.

Visit our MCD Biology Academic Planning Page where you will find blank plans, sample plans, and checklists for your majors.

MCD Biology Department Updates

We ask that students who need assistance with Academic Planning please meet with one of the MCD Biology Peer Advisors or attend an Academic Planning Workshop; once you have a completed Academic Plan, please share that plan with mcdadvising@ucsc.edu before scheduling an appointment with an MCD Biology Department Major Advisor. 

We are trying our best to continue to offer Drop-in, appointments, and respond to emails as quickly as possible.

Prerequisites and Enrollment Restrictions for MCD Biology Courses

The MCD Biology department has revised our prerequisites for most of our upper division courses – be sure to read the course descriptions for courses.

New Enrollment Restriction for BIOL 20A: First Pass Enrollment

Starting Spring 2025, BIOL 20A will have a First Pass Enrollment Restriction. Students must be one of the following proposed majors to be eligible to enroll in BIOL 20A during First Pass Enrollment: 

  • All Ecology and Evolutionary Biology (EEB) majors: Biology BA, Ecology and Evolutionary Biology BS,Marine Biology BS, Plant Sciences BS
  • All Molecular, Cell, and Developmental (MCD) Biology Majors: Biology BS, MCD Biology BS, Neuroscience BS
  • EEB/ENVS combined BA
  • Global and Community Health BS
  • Biochemistry and Molecular Biology BS
  • Microbiology BS
  • Science Education BS
  • Biomolecular Engineering BS
  • Biotechnology BA

During Second Pass Enrollment, all other majors (proposed or declared) will be eligible to enroll or waitlist BIOL 20A.

Interested in Research and Graduating in 2026 or 2027?

Interested in research, declared (Biology, BS or MCD Biology, BS or Biochemistry and Molecular Biology, BS), currently at or above junior level standing, and have not completed your Comprehensive Requirement/DC Lab course? Check out the MCD Biology departments 3 CUREs Lab offerings for Winter and Spring 2026.

The Course-based undergraduate research experiences (CUREs) are 2-quarter laboratory courses in which students are guided by a faculty member in an authentic research project. In contrast to traditional lab classes, the goal of the CUREs labs is the same as that of any research lab, to discover new knowledge.

For the 2025-2026 academic year, we are offering the following 3 MCD Biology CUREs Labs:

CRISPR-Cas Technology and the Immune System (105A/105B)

Faculty: Susan Carpenter

Capacity: 20 students

Prerequisites for BIOL 105A: BIOL 20L and BIOL 105. Enrollment is restricted to sophomore, junior, and senior MCDB B.S., BIOL B.S., and BIOC B.S. majors. Enrollment is by instructor permission. Interested students should add to the waitlist. Application will be required. Inquire with instructor.

Prerequisites for BIOL 105B: BIOL 105A and satisfaction of the Entry Level Writing and Composition requirements. Enrollment is restricted to sophomore, junior, and senior biology B.S. molecular, cell, and developmental biology, and biochemistry and molecular biology majors. Enrollment is by instructor permission. Interested students should add to the waitlist. Application will be required. Inquire with instructor.

Lab Description: This course investigates the groundbreaking CRISPR-Cas technology and its impact on immunology. You’ll explore the molecular mechanisms of CRISPR-Cas, its use in engineering immune cells for therapy, and the ethical implications. Instruction covers immunology, genomics, and CRISPR targeting for gene function studies in immune cells. You’ll also learn computational biology research relevant to your own project, where you’ll target a novel gene using CRISPR to determine its role in immune responses. This course lays the theoretical foundation and initiates the experimental lab work which will be expanded in BIOL 105B. 

Building on BIOL 105A, course provides hands-on experimental research in CRISPR-Cas technology and immunology. Students apply molecular mechanisms to learn about engineering immune cells for therapeutic purposes, consider ethical implications, and use CRISPR targeting to investigate gene function. Students conduct their own project, targeting a novel gene to determine its role in specific immune responses. This course focuses on experimental laboratory research using CRISPR as a genetic engineering tool.

There are two courses: BIOL 105A (5 Units) and BIOL 105B (5 units). BIOL 105A satisfies the requirement for BIOL 101L;  BIOL 105B satisfies the upper division 5 unit lab and fulfills the Disciplinary Communication (DC) and Comprehensive Lab requirements.

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Human Genetic Variation Laboratory (BIOL 104A/104B)

Faculty: Olena Vaske

Capacity: 20 students

Prerequisites for BIOL 104A: BIOL 20L and BIOL 105. Enrollment is restricted to sophomore, junior, and senior molecular, cell, and developmental biology B.S., Biology B.S., and biochemistry and molecular biology majors

Prerequisites for BIOL 104B: BIOL 104A and satisfaction of the Entry Level Writing and Composition requirements. Enrollment is restricted to sophomore, junior, and senior biology B.S. molecular, cell, and developmental biology, and biochemistry and molecular biology majors. BIOL 104B after receiving credit with a ‘C’ or better in BIOL 100L, BIOL 105L, BIOL 106L, BIOL 108L, BIOL 109L, BIOL 115L, BIOL 120L, BIOL 129L, BIOL 121L, BIOL 186L or METX 119L/100L.

Lab Description: This course together with its companion course BIOL 104B provide a supportive research immersion experience and training in computational and experimental approaches in cancer genomics. Instruction in cancer biology, genomics, and applications of genomic analysis for precision medicine is provided. Students work on their own projects to identify, visualize and interpret genetic variants that contribute to human cancers. BIOL104A focuses primarily on computational biology research, while BIOL104B focuses on experimental laboratory research.

There are two courses: BIOL 104A (5 Units) and Biol 104B (5 units). BIOL 104A satisfies the Bioinformatics requirement (BIOL 104L or BME 110) for MCD Biology, BS majors;  BIOL 104B satisfies the upper division 5 unit lab and fulfills the Disciplinary Communication (DC) and Comprehensive Lab requirements.

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Synthetic Gene Regulation Lab (107L/108L)

Faculty: Rohinton Kamakaka

Capacity: 20 students

Prerequisites for BIOL 107L: BIOL 20L. Completion of BIOL 107L is necessary to enroll in BIOL 108L. Enrollment is restricted to sophomore, junior, and senior molecular, cell, and developmental biology B.S., Biology B.S., and biochemistry and molecular biology majors. Interested students should add to the waitlist. Application will be required. Inquire with instructor.

Prerequisites for BIOL 108L: BIOL 107L and satisfaction of the Entry Level Writing and Composition is required. Students cannot enroll in BIOL 108L after receiving credit with a ‘C’ or better in BIOL 100L, BIOL 103L, BIOL 105L, BIOL 106L, BIOL 109L, BIOL 115L, BIOL 120L, BIOL 121L, BIOL 186L and METX 100L. Enrollment by permission of instructor.

Lab Description: The Synthetic Gene regulation course is a goal-oriented research laboratory. Students are given a project and discuss and design experiments to reach that aim. Students develop molecular tools and use these and other methods to investigate various aspects of gene silencing in eukaryotes. An understanding of introductory biology and genetics is required. 

There are two courses: BIOL 107L (5 Units) and Biol 108L (5 units). BIOL 107L satisfies the requirement for BIOL 101L;  BIOL 108L satisfies the upper division 5 unit lab and fulfills the Disciplinary Communication (DC) and Comprehensive Lab requirements.

How to Enroll in the CUREs Lab for Winter 2026

To enroll in one of the CUREs Lab options above, please be sure to add yourself to the waitlist for the CUREs Lab you are interested in once Second Pass Enrollment has started on November 21, 2025; you may receive an application for the CUREs Lab to your ucsc.edu email address. If you have any specific questions about the lab, please reach out to the instructor.

Please remember – the waitlist is only available during Second Pass Enrollment (Starting November 21, 2025). If you are unable to waitlist for one of the labs, please complete the interest form below:

2025-2026 CUREs Lab Interest Form

Biology, BS

METX 100L (formerly METX 119L) has been approved to meet the Comprehensive Requirement and Disciplinary Communication (DC) Lab requirements for the Biology, BS major!

MCD Biology BS

The Bioinformatics Requirement for the MCD Biology, BS major can be met in 3 different ways (applicable to all catalogs):

  1. BIOL 104L:  Introduction to Bioinformatics Lab – next offering of BIOL 104L will be in Spring 2026
  2. BME 110: Computational Biology Tools – offered Winter 2026 and Spring 2026
  3. BIOL 104A: Human Genetic Variation Laboratory (CURE Lab) – BIOL 104A will be offered in Winter 2026 only

Neuroscience BS

2026 Graduates, be sure you note the following limited course offerings:

BIOL 126: Neural Plasticity and Cognitive Neuroscience is being offered during the Winter 2026 quarter ONLY. Please remember that the Curriculum Plan is subject to change and should be checked frequently when class planning.

BIOL 128: Developmental Neurobiology is being offered during the Winter 2026 quarter ONLY. Please remember that the Curriculum Plan is subject to change and should be checked frequently when class planning.

BIOL 129L: Neurobiology Lab will be offered in Winter 2026 and Spring 2026 – be sure you have completed the prerequisites for the course! Prerequisites are: BIOL 100 and BIOL 101 or BIOC 100A and BIOC 100B, BIOL 101L (or equivalent), BIOL 125, and STAT 5 or STAT 7 and STAT 7L.

All 3 Advanced Topics courses are being offered this academic year! 

Upper Division Comprehensive Requirement/DC Lab Requirement

Biology BS majors: Please utilize the option of choosing the shaded electives on your checklist to meet the Comprehensive Requirement and DC requirements.

If you have already met the Comprehensive Requirement / DC, PLEASE do not enroll in another one! 

BIOL 105L Eukaryotic Genetics Lab

Fulfills the upper division lab requirement for Biology BS and MCD Biology BS.

Capacity of 20.

BIOL 115L Eukaryotic Molecular Biology Laboratory

Fulfills the upper division lab requirement for Biology, BS and MCD Biology, BS majors only. Capacity of 16.

BIOL 129L Neurobiology Lab

Fulfills the upper division lab requirement for Neuroscience, BS. Biology, BS and MCD Biology, BS majors can enroll in BIOL 129L during Second Pass Enrollment. Capacity of 20.

BIOL 186L Undergraduate Research in MCD Biology

Fulfills the upper division lab requirement for Biology BS, MCD Biology BS only. Enrollment is by application only. 

Please do not submit an application unless you already have a faculty member who is serving/willing to serve as your research mentor and you have carefully reviewed the course description. Capacity of 25. Priority will be given to students who submit an application by Friday, December 19th, 2025. 

Please be sure to attend the first class meeting of BIOL 186L even if your application is still in process. Not attending the first day of class may void your application.

More information regarding the BIOL 186 courses as well as other Undergraduate Research courses can be found on our Undergraduate Research webpage.

METX 100L General Microbiology Lab 

Formerly METX 119L. Fulfills the Comprehensive Requirement and DC Lab requirements for the Biology, BS major.

Please note the Enrollment Requirements in the Schedule of Classes – First Pass Enrollment is only for Microbiology, BS majors; Biology, BS majors can enroll in the course during Second Pass Enrollment. METX 100L is monitored by the Microbiology and Toxicology Department (METX).

MCD Biology, BS Majors following 2023-2024 or earlier catalogs can still complete METX 100L for the Comprehensive Requirement/DC Lab Requirement.

Important Policies for MCD Biology-Sponsored Majors:

  • Letter Grade Policy: All major and minor requirements require a letter grade. P Grades will not be accepted to satisfy major specific requirements. 
    • C- grades CANNOT be used to satisfy a major requirement and cannot satisfy a prerequisite for another course. You must repeat a course if you receive a C- grade for major or pre-requisite credit. Only grades of “C” (2.0) or better will fulfill major requirements.
  • Course Substitution & Transfer Credit Policy: Once matriculated, MCD Biology sponsored majors must complete the Core Courses (BIOL 20A, 100, 105, 101 and 110) at UCSC. If you are a Transfer student or have transfer/test credit from prior to your matriculation at UCSC, please meet with an MCD Biology Advisor for clarification.

Student Opportunities Email Google Group

Join our new Student Opportunities Email Google Group to receive messages regarding opportunities shared with MCD Biology Advising from: other departments at UCSC, California state graduate schools, job, scholarship, research, training, volunteer & internship opportunities. You can unsubscribe at any time.

This Google Group is optional and you must register yourself at the link below – please note you can leave the group at any time.

New Student Opportunities Email Google Group: MCDB FWD Opportunities!


Best wishes for a wonderful quarter,

Jeannette, Kylie, and Leanna

MCD Biology Undergraduate Advising

Department of Molecular, Cell, and Developmental Biology

Division of Physical and Biological Sciences

Related Links:

Last modified: Nov 12, 2025