What is the difference between a primary and secondary follicle? a) A primary follicle has a single layer of follicular cells; whereas a secondary follicle has multiple layers of granulosa cells b) A primary follicle contains the primary oocyte; whereas the secondary follicle contains a secondary oocyte c) A primary follicle has a single layer of granulosa cells; whereas a secondary follicle has multiple layers of follicular cells d) A primary follicle contains a pool of follicular fluid called the antrum; whereas a secondary follicle does not contain an antrum.