You are required to submit all HS and College transcripts upon enrolling at any UC. If the Marketing class is on a transcript, you are required to submit it as part of your provisional admission contract regardless if it is UC transferable. There is a Clearing house that has a record of college courses taken so just inform UCSC of the course. Better to let them know now than have them find out you purposely left it off your application and did not send the transcript. If it is a non- transferable class it should not be an issue.