What are we learning today?

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What are we learning today?

1. What are the phases of meiosis and what happens
   during each phase?
2. What is the significance of meiosis to sexual
   reproduction?

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What are we learning today?

1. How are mitosis and meiosis similar?
2. How are mitosis and meiosis different?

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Meiosis
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Cell basics

• Somatic cells have two sets of chromosomes.
• One from each parent.
• Includes all cells in your body except gametes
• Somatic cells are diploid.

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Cell basics

• Diploid contains two sets of chromosomes
• The two chromosomes in each pair are called
  homologous.
• Humans have 23 pair of homologous chromosomes.

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Cell basics

• Autosomes all chromosomes in the cell except
  the sex chromosomes X Y
• Humans have 22 pair of autosomes and 1 pair of
  sex chromosomes.

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Cell basics

• For reproduction to occur, the chromosome number
  must be reduced by ½.
• Remember, in a somatic cell, one chromosome came
  from each parent

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Meiosis

• Meiosis cell division which results in the
  production of gametes with half the number of
  chromosomes
• When fertilization occurs, the zygote will
  contain the full set of homologous chromosomes

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Meiosis

• The cells produced from meiosis are haploid
• Haploid cells with one copy of each chromosome.
• Gametes are haploid.

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Meiosis

• The phases of meiosis are similar to mitosis
• Meiosis consists of 2 divisions of the cell.
• The result is four daughter cells.

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Stages of Meiosis

• The stages of meiosis are named prophase,
  metaphase, anaphase, telophase
• The 2 cell divisions are distinguished by I or
  II

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Result of Meiosis

• Four haploid cells called gametes
• Four daughter cells not identical to the parent
  cell.
• Gametes are necessary for sexual reproduction

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What are we learning today?

1. What are the phases of meiosis and what happens
   during each phase?
2. What is the significance of meiosis to sexual
   reproduction?

15
What are we learning today?

• How are mitosis and meiosis similar?
• How are mitosis and meiosis different?