| Spermatogenesis | Oogenesis |
| 1. Spermatogenesis occurs in the testes | 1. Oogenesis occurs in ovaries |
| 2. Spermatogonia change to primary spermatocyte | 2. Oogonia change to primary oocyte |
| 3. A primary spermatocyte divides to form two secondary spermatocyte | 3. A primary oocyte divides to form one secondary oocyte and one polar body |
| 4. A secondary spermatocyte divides to form two spermatids | 4. A secondary oocyte divides to form one ootid and one polar body |
| 5. No polar body is formed | 5. Polar bodies are formed |
| 6. Four spermatozoa are formed from one spermatogonium | 6. One ovum is formed from an oogonium |
| 7. Sperm is motile and yolkless | 7. Egg or ovum is non-motile and with yolk |