Answer:
A primary oocyte residing in a primordial follicle becomes a secondary oocyte in the vesicular follicle.
Step-by-step explanation:
Oocytes are female germ cells or sex cells produced in the ovaries. They result from a physiological process called oogenesis.
During this process, two types of oocytes are formed, Ovocyte I (primary oocyte) and Ovocyte II (secondary oocyte).
The primordial follicle contains a primary oocyte surrounded by cuboidal follicular cells or flat cells. The secondary follicle has its formation in the mature vesicle follicle, ready to be ovulated.