Meiosis

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Meiosis
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Meiosis

• formation of gametes
• sperm and egg (haploid)
• fertilizationuniting to form a diploid zygote
• reduction and division

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Fertilization
Sperm and egg uniting
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Haploid vs. Diploid

• Cells having two sets of chromosomes are diploid
  (2n).
• Haploid cells (1n) have only one set of
  chromosomes.

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Meiosis Phases

• Meiosis I includes prophase I, metaphase I,
  anaphase I, and telophase I.
• Meiosis II includes prophase II, metaphase II,
  anaphase II, and telophase II.

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Development of Gametes

• Spermatogenesis is the process by which sperm
  cells are produced.
• Oogenesis is the process that produces mature egg
  cells.

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Chromosome Numbers

• Sex Chromosomes
• Sex chromosomes are chromosomes that determine
  the sex of an organism.
• Autosomes
• All of the other chromosomes in an organism

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Female
Male
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Down Syndrome Karyotype(trisomy 21)
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Crossing Over

• Crossing-over, which is when portions of
  homologous chromosomes exchange genetic material,
  occurs during prophase I and results in genetic
  recombination.

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Mitosis vs. Meiosis

• Meiosis leads to four haploid cells (gametes)
  rather than two diploid cells as in mitosis.

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Mitosis vs. Meiosis

• mitosis v meiosis