Spermatogenesis
- Spermatogenesis is the process of the formation of haploid sperms from a diploid stem cell known as spermatogonium.
- The process occurs inside the seminiferous tubules in the testis.
- The entire process takes about 70 days.
- Spermatogenic germ cells are called spermatogonia.
- Spermatogonia are stem cells that are capable of self-renewing.
- They differentiate into intermediate spermatogonium, which is committed to differentiating into spermatozoa.
Oogenesis
- Oogenesis is the process of formation of the ovum.
- The process occurs in the ovaries of the female.
- One oogonium produces a single ovum.
- Primary oocyte is the diploid cell, which is divided by meiosis, forming a single ovum.
- Oogenic germ cells are called oogonia, which are stem cells, self-renewing and differentiating into ova.
Difference Between Spermatogenesis and Spermiogenesis
| Properties | Spermatogenesis | Oogenesis |
| Definition | The production of sperms from spermatogonia is called spermatogenesis. | The production of eggs from oogonia is called oogenesis. |
| Oogenesis | Occurs in male | Occurs in female |
| Growth phase | Too short | Prolonged |
| Formation | Seminiferous tubules of testis | In ovaries |
| Process | Production of sperms from spermatogonia | Production of ovum from oogonia |
| Cell Division | All spermatogonia are divided by meiosis, producing sperms all the times. | Some of the oogonia divide during the production of eggs, one at a time. |
| Continuity | Spermatogenesis is a continuous process, occurring after the puberty till death. | Early stages of the oogenesis occurs during the fetal period. The rest of the process occurs after the puberty. Only one ovum is produced per month until menopause. |
| Production of ovum from oogonia | Continuous, occurs after the puberty till death | Discontinuous, occurs after the puberty until menopause |
| Nuclear condensation | Found | Absent |
| Sertoli cells | Sertoli cells are found in the germinal cell epithelium, supporting the germinal cells. | No Sertoli cells are found in the germinal cell epithelium. |
| Food reserve | Sperm contains less food reserve | Ovum contain a lot of food reserve |
| Stages | All stages occurs inside the testis | Except the last stage which occurs in oviduct, all stages occurs inside the ovary |
| germ line epithelium | Involved in gamete production | Not involved |
| Location | Occurs entirely in testes | Occurs mostly in ovaries |
| Meiotic Division | Equal division of cells | Unequal division of cytoplasm |
| Primary Gametocyte | Primary spermatocyte is divided by meiosis 1, forming two secondary spermatocytes. | Primary oocyte is divided by meiosis 1, forming a secondary oocyte and one polar body. |
| Secondary Gametocyte | Secondary spermatocyte is divided by meiosis 2, forming two spermatids. | Secondary oocyte is divided by meiosis 2, forming ovum and one polar body. |
| Cytokinesis | Equal | Unequal |
| Number of gametes produced | 4 | 1 (plus 2 -3 polar bodies) |
| Size of gametes | Sperm smaller than spermatocytes | Ova larger than oocytes |
| Duration | Uninterrupted process | In arrested process |
| Onset | beings at puberty | Begins in foetus (pre-natal) |
| Release | continuous | Monthly from puberty (menstrual cycle) |
| Initiation of process | Begins at puberty | Begins even before birth |
| Motility | Sperm are motile | Ovum is immotile |
| Starting cells | Start from a primary spermatocyte | Start from a primary oocyte |
| Result | Forms four motile male gametes i.e. sperms | Forms one non-motile female gamete i.e. ovum |
| Releasing | Sperms are released from the testis | Oocytes are released from the ovary which matures later |
References
- https://biologyreader.com/difference-between-spermatogenesis-and-oogenesis.html
- https://ib.bioninja.com.au/higher-level/topic-11-animal-physiology/114-sexual-reproduction/gametogenesis.html
- https://www.differencebetween.com/difference-between-spermatogenesis-and-vs-oogenesis/
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