The courses are equivalent and are anti-requisites of each other. 2B03 is for second years in the Faculty of science and Hth Sci 2K03 is only for those in the faculty of health science(the prerequisite courses for it are ones which you can only take if you were in health science i.e. 2D06, 2E03, 2N03)
This is from the undergrad calendar under Hth Sci 2K03:
An inquiry based examination of the relationship between cell structure and function. Students will be required to apply key concepts of cell biology to facilitate their understanding of timely problems in biomedicine.
Tutorials (three hours); Problem Based Learning and Computer Laboratories (three hours); one term
Prerequisite(s):
CHEM 1AA3,
HTH SCI 1I06; and
HTH SCI 2D06,
2E03 or
2N03
Antirequisite(s):
BIOLOGY 2B03, MOL BIOL 2B03