The Meaning of Sex: Genes and Gender

Lecture 1 – Deciphering the Language of Sex

by David C. Page, MD

  1.  1.  Start of Lecture 1
  2.  2.  Introduction by HHMI President Dr. Thomas Cech
  3.  3.  Introductory interview with Dr. David Page
  4.  4.  What was the first thing your parents asked about you?
  5.  5.  Characteristics of male and female
  6.  6.  Electron micrograph of egg and sperm
  7.  7.  Embryonic development and the role of gonads
  8.  8.  Sex determination can't be explained by the historical idea that heredity is a blending process
  9.  9.  Historical ideas on environmental factors affecting sex determination
  10. 10.  Early-20th-century scientists find sex chromosomes in insects
  11. 11.  What might the sex-determining signal be?
  12. 12.  Sex of fruit flies linked to number of X chromosomes in 1916
  13. 13.  Discovery of how sex chromosomes operate in humans
  14. 14.  XX males and XY females suggest key genes for sex determination
  15. 15.  SRY, the sex-determining gene, in transgenic mice
  16. 16.  Student question: What are the symptoms of Turner and Kleinfelter syndromes?
  17. 17.  Student question: What causes hermaphroditism in humans?
  18. 18.  Student question: Why don't XX males produce sperm?
  19. 19.  Student question: What makes XY females develop as female?
  20. 20.  Student question: Does SRY determine whether a person has testes?
  21. 21.  Student question: Can Y-chromosome activity be clearly observed in the human body?
  22. 22.  Student question: Do XY females have male levels of testosterone?
  23. 23.  Why does nature have two sexes? Are males really necessary?
  24. 24.  Description of clonal reproduction
  25. 25.  Comparing cloning in Laredo striped whiptail with sexual reproduction in related species
  26. 26.  Meiosis is the defining feature of sexual reproduction
  27. 27.  Is sex, in an evolutionary sense, good?
  28. 28.  Demonstration: Fresh fruit and rotting vegetables
  29. 29.  Demonstration: Fruit and vegetables with mutations
  30. 30.  Demonstration: Meiosis can weed out rotten genes
  31. 31.  Animation: Meiosis
  32. 32.  Animation: Picture sequence of human embryonic development
  33. 33.  Animation: How does an X chromosome gain the SRY gene?
  34. 34.  Student question: With a recessive mutation, would a clonal reproducer be better off?
  35. 35.  Student question: Is lizard cloning the same as cloning in Dolly the sheep?
  36. 36.  Closing remarks by HHMI President Dr. Thomas Cech

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