Final answer:
A primary oocyte undergoing meiosis I and subsequent cytokinesis produces a secondary oocyte and a polar body. The secondary oocyte contains most of the cell's contents and is the one that may be fertilized and proceed to meiosis II, while the polar body typically degrades.
Step-by-step explanation:
When a primary oocyte undergoes meiosis I and then cytokinesis, two cells are produced: a larger cell called a secondary oocyte and a smaller cell known as a polar body. The primary oocyte divides unequally, with the secondary oocyte receiving most of the cytoplasm and a set of chromosomes, while the polar body gets a set of chromosomes but minimal cytoplasm and is usually not viable. The secondary oocyte may proceed to meiosis II if fertilized by a sperm, leading to the development of a fertilized egg with the complete set of human chromosomes.
The process of oogenesis, which begins before birth, involves the mitotic division of oogonia to form primary oocytes. These primary oocytes undergo meiosis I during a woman's reproductive years after a surge of luteinizing hormone.