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Sperm formation:

  • A male begins to produce sperm during puberty.
  • Seminiferous tubules within each testes form sperm.
  • Near the outer surface of these tubules there are undifferentiated cells called spermatogonia. These are stem cells that remain able to divide.
  • The process of making and maturing a sperm cell begins with spermatogonia. Spermatogonia undergo meiotic divisions leading to sperm formation.
  • Sperm production involves several cell divisions called mitosis and meiosis.
  • Mitosis produces diploid cells, and meiosis produces haploid cells
    • meiosis division - reduction division; forms reproductive cells in humans; takes place only in the testes during sperm production; chromosome number is reduced from the normal 46 to 23 during production of sex cells (sperm has 23 chromosomes)
    • mitosis division - duplication division; duplicates cells; ensures chromosome number stays constant i.e., 46 chromosomes
  • Sertoli cells provide nutrition to the dividing germ cells i.e., regulate the process of spermatogenesis.
  • Thus spermatogenesis (the process of sperm formation) by the process of meiosis and maturation takes about 65-75 days for the sperm to go through the growth from spermatogonia to sperm.
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