Course Meetings

Classes are held twice a week and involve a mixture of lecture and active participation, including back-of-the-envelope estimations, derivations, and natural philosophy. The course is intended to serve as an introduction to the overarching principles of modern biological inquiry, with special attention to how they relate to physics, chemistry, mathematics, engineering, and computer science.

Recitations are held once a week. These sessions are led by pairs of graduate and/or undergraduate TAs, and are designed to help guide your thinking on problem sets, and further explore topics introduced in class. Feel free to attend whichever section is most convenient, within room capacity limits.

Tutorials are also held once a week, hosted by the head TAs. These supplementary sessions are designed to be exploratory extensions of each week’s content. Examples include a crash course in programming with Python and a live microbiology experiment.

Attendance, Grading, and Electronic Devices

Regular attendance is an expectation for all students in the class. There is no textbook, so you will likely find it difficult to stay on top of the material otherwise. As a general rule, “on time” means that you are sitting in the classroom five minutes early.

There will be no exams, quizzes, reports, or research proposals; your final grade is based entirely on homework. Homework is assigned on Thursdays and is due the following Thursday at 11:59 pm. Late homework submissions (submitted after 11:59 pm on the date due) will not be accepted without penalty. For each day an assignment is late, 10% will be deducted from the maximum possible score, beginning immediately after the deadline. For example, if your submission is handed in at 1:00 am on the Friday after it is due, your maximum possible score is 90%. A submission received four days late will maximally earn 50%. For exceptions, see “Absences, Extensions, and Ditch Day” below.

You may use an electronic device (e.g. tablet, laptop) to take notes during class only if you use it for this purpose. We will ask you to turn off your electronic devices (or ask you to leave) if their use is off-topic or distracting to others.

Homework Submissions

To ensure proper grading, all homework must be submitted in adherence to the following conventions:

  • For text solutions, submit a single PDF with the filename lastname_firstname_hw#.pdf to Gradescope. This can be scanned handwritten work, but LaTeX is preferred. Assign the pages corresponding to each problem using Gradescope’s UI when you do so.
  • For code solutions, submit a completed Colab template notebook with the filename lastname_firstname_hw#.ipynb to Canvas. Details on how to work with Colab can be found on the tutorials page.

Any submission that does not completely adhere to these requirements will not be graded.

Homework Regrades

If you are interested in challenging the way your homework was graded, you may request a regrade. Regrades are subject to the following conditions:

  • Each regrade request applies to one assignment. In other words, if you ask for a regrade, the entire homework will be subjected to the same high level of scrutiny you have requested for the problem you feel was not graded properly. Keep in mind that this could result in a net reduction in your grade on that particular assignment.
  • Regrades are final.

To request a regrade:

  • For solutions submitted to Gradescope, please use the platform’s built-in regrade feature.
  • For solutions submitted to Canvas, email Kian with the subject line [Homework #] Regrade Request. You may provide a description of any mistakes you feel were made in the body of the email.

Collaboration Policy and the Honor Code

You are expected to follow the Caltech Honor Code at all times. As a reminder, this states:

No member of the Caltech community shall take unfair advantage of any other member of the Caltech community.

Collaboration is imperative to scientific discovery. You are encouraged to work together on homework assignments, but all work handed in must be your own. This means that you may not hand in work copy-pasted from those you worked with.

For programming, please follow the 50-foot rule from CS11:

[...] If you help another student with their programming problems (including debugging), you must not consult your own code while doing so. Specifically, we ask that your own code be at least 50 feet away i.e. not visible to you or the person you are helping while you are helping them. This means that you may work with each other on programming problems but you may not copy others code directly. [...] Help them with your brain, not with your code.

You may use resources on the internet, primary literature, or textbooks to help you answer questions, although you must provide a reference. You may not refer to homework questions or solutions from previous editions of this course or others like it.

We have designed the tutorials to provide you with all of the information you need to complete the coding problems in the homework. While you may use any of the code provided in the tutorials to solve your homework, please do not just copy-paste it directly into your notebook. This is a good way to learn absolutely nothing. Instead, type it out by hand and ensure you understand what each line actually does.


You may contact the TAs via email at any time, but please don’t be spammy or rude. TAs are generally not expected to reply to emails outside of normal hours, although your TA may have different preferences. Remember that you are reaching out to another human!

In most cases, emailing your section TA is preferable to emailing a head TA, which is preferable to emailing Rob. Use your best judgment.

Absences, Extensions, and Ditch Day

Homework extensions or absences will only be granted with an adequate reason (e.g. a note from a doctor or dean), and with as much advance notice as possible. Last-minute requests (or requests after the deadline) will generally not be granted. To request an extension, email Kian with the subject line [Homework #] Extension Request.

In the event that Ditch Day falls on the day that an assignment is due, the deadline will be extended by two calendar days (i.e., if Ditch Day is on a Thursday when a problem set is due, then the revised due date will be Saturday at 12:00 pm). Any course meetings affected by Ditch Day will be rescheduled and posted on the homepage.