Reproduction

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Reproduction

• Meiosis

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• In order for living things to remain on earth,
  they must reproduce!
• If an organism does not reproduce, that type of
  organism would disappear as soon as death occurs.

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• By reproducing, animals ensure that their species
  will continue to exist.

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Methods of Reproduction

• Asexual reproduction that occurs when one
  parent creates another organism.
• Sexual each parent contributing genetic
  material to the young.
• Half of the characteristics come from the father
  and half from the mother.

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Reproductive Cells

• Reproductive cells are referred to as gametes.
• The male gamete is known as a sperm cell.
• The female gamete is known as an egg cell.

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Reproductive Cells

• When the male gamete and the female gamete unite
  (fertilization), a zygote is formed.
• A zygote is a fertilized egg.
• The zygote will divide (through mitosis) and will
  begin to develop into an embryo.

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Production of Gametes

• The formation of the male gamete (sperm cell)
  takes place in the testicles of the male.
• The formation of the female gamete (egg cell)
  takes place in the ovaries of the female.

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Production of Gametes

• Within these organs, a process known as meiosis
  takes place.
• Meiosis is cell division that results in
  daughter cells that contain only half of the
  number of chromosomes of the original cell.
• Meiosis is necessary in order to allow for the
  contribution of half of the chromosomes by each
  parent.

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Meiosis

• Meiosis is a multi-step process that creates
  gametes with one-half of the original number of
  chromosomes as the parent.
• The production of the male gamete is called
  spermatogenesis.
• The production of the female gamete is called
  oogenesis.

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Process

• Sex cells first undergo mitosis
• Then it repeats the steps again
• Prophase II
• Metaphase II
• Anaphase II
• Telophase II

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Meiosis

• The stages of spermatogenesis include
• Spermatogonia process where cells are produced
  in the testes

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Meiosis

• The end result of this process is that four new
  sperm cells are produced from the original cell,
  and each new cell contains half the number of
  chromosomes as the original cell.
• When the sperm unite with the egg, the total
  number of chromosomes is restored.

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Meiosis

• The production of the female gamete (oogenesis)
  is similar to that of sperm production.
• However, only one cell becomes a viable egg,
  while the other three become polar bodies, and
  provide sustenance (food) for the egg until
  conception.

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