What structures in the ovary contain immature ova?

The structures in the ovary that contain immature ova are follicles. Follicles are specialized sacs in the ovaries where oocytes, or immature eggs, develop. As a female matures, several follicles begin to develop during each menstrual cycle, although typically only one becomes fully mature and is released during ovulation. Each follicle contains an oocyte surrounded by granulosa cells that nourish and support the developing egg.

Ovarian cysts, although they are fluid-filled sacs that can form on the ovaries, do not specifically refer to structures that contain immature ova but rather can arise from various types of follicles or other conditions. The corpus luteum, formed after ovulation from the remnants of the follicle, plays a crucial role in hormone production but does not contain immature ova. Graafian follicles, also known as mature follicles, are specifically the stage just before ovulation and contain a mature oocyte, not an immature one. Thus, it is the follicles that encompass those early developmental stages of the ova.