Top 16 Differences Between Oogenesis And Spermatogenesis (With Similarities)

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What Is Spermatogenesis?

Spermatogenesis is the process by which Spermatozoa develop from the Germ cells in the seminiferous tubules of the testis. Spermatogenesis is a complex process involving mitotic cell division and it begins at puberty and continues for the remainder of a male’s life. Both gametes are haploid cells which contain 23 unpaired chromosomes, which is half of the human genetic makeup. When these haploid cells meet they form a zygote or a fertilized egg which contains a total of 46 chromosomes.

The Process of Spermatogenesis

Sperm cells undergo a series of cellular changes and division in order to fully develop. First, during meiosis 1, two haploid cells form from one diploid cell. Then during Meiosis II, sister chromatids split to create four daughter cells. Through this process, each daughter cell receives a unique combination of the male’s genes, ensuring genetic diversity. The cell begin as a spermatogonium  (undeveloped diploid cell and ends as four spermatids. These spermatids form the fully developed sperm cell that comprises semen.

What You Need To Know About Spermatogenesis

  1. Spermatogenesis is the formation of sperms (male gamates).
  2. It occurs in males, inside testis
  3. Spermatogonia develop from germinal epithelium lining, the seminiferous tubules.
  4. It is a continuous process and completed in approximately 74 days.
  5. Both maturation divisions are completed in testes themselves.
  6. A spermatocyte forms four spermatozoa.
  7. A primary spermatocyte divedes by Meiosis I to form two secondary spermatocytes.
  8. To take part in reproduction, the spermatids have to transform into thread like sperms by the process of spermiogenesis.
  9. Secondary spermatocyte divides by meiosis II to produce two spermatids.
  10. Reserve food is little in the sperms.
  11. Sperms are smaller than spermatocytes.
  12. Nucleus undergoes condensation in the sperm.
  13. Some of the cells of germinal epithelium function as support also referred to as sertoli cells.
  14. All the spermatogenia divide to form spermatocytes.
  15. The process produces motile male gametes.
  16. Growth phase is shorter.

Also Read: Difference Between Sporic, Gametic And Zygotic Meiosis

What Is Oogenesis?

Oogenesis is the process through which female gametes (ova) are created. The process of meiosis in human female gametes is different from the process of meiosis in male gametes whereby four haploid gametes are created from a single diploid cell. Also, unlike the male gametes that are continuously produced from puberty onwards, female production of gametes occurs entirely before birth with maturation occurring in pulsatile fashion after puberty.

The process of Oogenesis

When the primary Oocyte does finally complete its first meiotic division, it divides the chromosomes evenly; however, it does not divide the cytoplasm equally. Almost all of the cytoplasm remains in one of the two daughter cells, which becomes a secondary oocyte. The other daughter cell, which gets half of the chromosomes but very little in the cytoplasm, is referred to as a polar body. The polar body not being a functional oocyte eventually degenerates and dies. The formation of polar body allows the primary oocyte to reduce its genome by half and conserve most of its cytoplasm in the secondary oocyte. Eventually, the secondary oocyte still having two copies of each chromosome becomes an ovum.

What You Need To Know About Oogenesis                                                           

  1. Oogenesis is the formation of eggs in females.
  2. Occurs in females, inside the ovary.
  3. Oogonia develop from germinal epithelium overlying the ovary.
  4. It is a discontinuous process and completed in a few days to years.
  5. First maturation division is completed in the ovaries but the second one is completed outside ovaries after fertilization begins.
  6. A oocyte forms only one egg or ovum.
  7.  A primary oocyte divides by meiosis I to form one secondary oocyte divide and one polar body.
  8. Ootids  as such take part in reproduction.
  9. Secondary oocyte divides by meiosis II to form one ovum and one polar body.
  10. Ovum has a lot of reserve food and other biochemicals.
  11. Eggs are larger than oocytes.
  12. Nucleus remains uncondensed in the ovum.
  13. There is usually no such differentiation.
  14. Only one oogenia give rise to oocytes.
  15. The process produces non motile female gametes.
  16. Growth phase is prolonged.

Also Read: Difference Between Estrogen And Progesterone

The Differences Between Oogenesis And Spermatogenesis In Tabular Form

Basis of Comparison Oogenesis Spermatogenesis
Definition Spermatogenesis is the formation of sperms (male gamates).   Oogenesis is the formation of eggs in females.  
Occurrence It occurs in males, inside testis.   Occurs in females, inside the ovary.  
Development Spermatogonia develop from germinal epithelium lining, the seminiferous tubules.   Oogonia develop from germinal epithelium overlying the ovary.  
Type of Process It is a continuous process and completed in approximately 74 days.   It is a discontinuous process and completed in a few days to years.  
Maturation Divisions Both maturation divisions are completed in testes themselves.   First maturation division is completed in the ovaries but the second one is completed outside ovaries after fertilization begins.  
  Gametes A spermatocyte forms four spermatozoa.   A oocyte forms only one egg or ovum.  
Divisions of Gametes A primary spermatocyte divedes by Meiosis I to form two secondary spermatocytes.   A primary oocyte divides by meiosis I to form one secondary oocyte divide and one polar body.  
Reproduction To take part in reproduction, the spermatids have to transform into thread like sperms by the process of spermiogenesis. Ootids  as such take part in re production.  
Products of Meiosis II Secondary spermatocyte divides by meiosis II to produce two spermatids. Secondary oocyte divides by meiosis II to form one ovum and one polar body.  
Reserve Food Reserve food is little in the sperms.   Ovum has a lot of reserve food and other biochemicals.  
Size of the Gamates Sperms are smaller than spermatocytes.   Eggs are larger than oocytes.  
Nucleus Nucleus undergoes condensation in the sperm.   Nucleus remains uncondensed in the ovum.  
Differentiation of Cells Some of the cells of germinal epithelium function as support also referred to as sertoli cells.   There is usually no such differentiation.  
Product of Division All the spermatogenia divide to form spermatocytes. Only one oogenia give rise to oocytes.  
Motility of Gametes The process produces motile male gametes.   The process produces non motile female gametes.  
Growth Phase Growth phase is shorter.   Growth phase is prolonged.  

Also Read: Difference Between Meiosis And Mitosis

Similarities Between Spermatogenesis And Oogenesis

  • Each process has three steps that are; multiplication, growth and maturation.
  • These two processes occur in germ cells.
  • Meiosis occurs in both processes.
  • Both processes are extremely important in sexual reproduction.
  • They both result in a haploid cell at the end.
  • Both spermatogenesis and oogenesis start from a diploid cell.

Also Read: Difference Between Chromatin And Chromatid

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