What is one difference between a primary oocyte and a secondary oocyte in humans?

1. primary oocytes

- diploid (2 complete sets of chromosomes)

- 'formed' from oogonia during the process of oogenesis

* primordial follicles consist of a primary oocyte + a single layer of squamous follicle cells

* primary follicles consist of a primary oocyte + 1/several layers of cuboidal follicle cells

2. secondary oocytes

- haploid (1 complete set of chromosomes)

- developed from the primary oocyte undergoing meiosis I to form a secondary oocyte + a tiny first polar body

* found in the matured Graafian follicle

* begins meiosis II & stops at metaphase II upon ovulation & only continues upon fertilisation