A primary oocyte residing in a primordial follicle becomes a secondary oocyte in the vesicular follicle.
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.
All eukaryotic cells have membrane covered compartment called organelles. They include the nucleus, the Golgi, mitochondria, endoplasmic reticulum and many others. So the answer is- organelles. ;)
