Reduction-Division

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Homologs separate

Slide 27

Telophase I

Each pole now has haploid (1n) set of chromosomes.

Cytokinesis occurs and two haploid daughter cells are formed.

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Telophase I

cytokinesis

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MEIOSIS II

Sister Chromatids Separate

Meiosis II

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Meiosis II

No Interphase II or very short

No DNA Replication

Remember: Meiosis II is similar to mitosis

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Prophase II

Same as Prophase in mitosis

Nucleus & nucleolus disappear

Chromosomes condense

Spindle forms

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Metaphase II

Same as Metaphase in mitosis

Slide 33

Anaphase II

Same as Anaphase in mitosis

SISTER CHROMATIDS separate

Slide 34

Telophase II

Same as Telophase in mitosis.

Nuclei and Nucleoli reform, spindle disappears

CYTOKINESIS occurs.

Remember: FOUR HAPLOID DAUGHTER cells are produced.

Called GAMETES (eggs and sperm)

1n Sperm cell fertilizes 1n egg to form 2n zygote

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Telophase II

Slide 36

Slide 37

Variation

Also known as GENETIC RECOMBINATION

Important to population as the raw material for NATURAL SELECTION.

All organisms are NOT alike

Strongest “most fit” survive to reproduce & pass on traits

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Question:

What are the 3 sources of genetic recombination or variation?

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Answer:

CROSSING OVER (prophase I)

INDEPENDENT ASSORTMENT (metaphase I)

RANDOM FERTILIZATION

Slide 40

Question:

A cell containing 20 chromosomes (diploid) at the beginning of meiosis would, at its completion, produce cells containing how many chromosomes?

Slide 41