Mitosis and Meiosis

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Mitosis and Meiosis
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Onion (Allium) Root Tip
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Location of Mitotic Cells on Root Tip
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Stages of Mitosis in Onion Root Tip
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Whitefish Blastula Mitotic stages
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Grasshopper Testis
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Spermatogenesis Grasshopper TestesSpermatogonia
(not yet in meiosis)
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Primary Spermatocyte in Meiosis I 2n
chromosomes, tetrads Secondary Spermatocyte in
Meiosis II, 1n chromosome, dyads
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Grasshopper Testis
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Spermatids, 1n
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Mature Spermatozoa, 1n
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Mammalian Testes Slide 10 p. 3 diagram

• Seminiferous tubules tightly coiled tubules (
  500 m) where millions of sperm are produced.
• Epididymis sperm travels and matures in a 1-3
  week journey.

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Interstitial space Leydig cells ? Testosterone
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Interstitial space Leydig cells ? Testosterone
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Ascaris Oviduct Uterus
P. 4 diagram
Sperm Penetration Notice Sperm head (haploid)
have entered the eggs. Meiosis in the egg can
only resume after sperm penetration. Note the
lack of extensive membranes which will be seen to
surround the egg later.
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Ascaris
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Ascaris
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Ascaris