Depends on the subject. Chemistry and biology I took at community college, where chem was one credit with a grade which was separate from the 5 credit lecture class (quarter system), and biology was 5 or 6 credits all lumped into one grade. I took first quarter of physics there too and it was 4 lecture credits and 1 lab credit, although there wasn't a real "lab" and we received the same grade for both.
At my university organic chemistry lab was separate from lecture, lab was 3 credits and lecture was 4, both received separate grades. Physics here is just one credit and pass/fail. I believe that at least chemistry works roughly the same as organic chemistry here, but I could be mistaken.