Spermatogenesis is the formation of male gametes or sperm and has four phases: multiplication, growth, maturation, and spermiogenesis. During the multiplication phase, primordial germ cells undergo mitosis to form many spermatogonia. In the growth phase, spermatogonia grow in size but do not divide to form primary spermatocytes. During maturation, primary spermatocytes undergo two rounds of meiotic division to form four spermatids. Finally, spermiogenesis is when each spermatid undergoes changes to become a motile sperm cell.

1. Spermatogenesis is
formation of male
gametes sperm.
It has 4 phases
Multiplication
phase
Growth phase
Maturation phase
Spermiogenesis

2. Multiplication phase
•In the crypt germinal epithelial cells found called
primordial germ cells(2n)
•These cells undergo repeated mitosis to form
large no of spermatogonia (2n).

3. Growth phase
•Each spermatogonium grow in size to form
primary spermatocyte (2n).
•So their no is as many as spermatogonia.
•No division takes place.

4. Maturation phase
• Primary spermatocyte undergoes two meiotic divisions to form 4cells
called spermatid(n).
• First meiotic division is called 1st maturation division.
• In this division primary spermatocyte divide to form two secondary
spermatocyte (n).
• Secondary spermatocyte undergoes 2nd meiosis called 2nd maturation
division.
• After this two secondary spermatocytes form 4 spermatids(n).

5. Spermiogenesis
• Each spermatid undergoes a modification process to form sperm.
• It is spermiogenesis.
• Rounded spermatid becomes elongated sperm.
• Spermatid is non motile but sperm is motile.
• Golgibody forms the acrosome of sperm.