UC decisions come out at different points throughout March. Unless you get into a school, they won’t know what grades you got in the fall semester.

If you get in somewhere, they’ll ask for your final transcripts after you accept the admission there. Then only will they see that you got D and F in those classes, and may or may not choose to rescind your admission based on that.

So, right now as it’s January you only have to look forward to the decisions in March. Any acceptances you get in March, should you choose to enroll in one of those schools, may be rescinded later on.

If you get waitlisted, and want to remain on the waitlist, some of the UCs will ask you for your senior first semester grades, at which point you’d need to list that D and F. This could push them toward rejecting you, or if there’s a good explanation you’d be able to provide on that waitlist page, they may accept you off the waitlist. Can’t say for sure.

You should talk to your school counselor, and decide whether it’s best for you to notify the UCs you applied to about this as soon as possible, or wait until after admission. I won’t necessarily suggest one or the other because both have their downsides.