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Human Heredity

Human Heredity. http://www.youtube.com/watch?v=hNMYV213xu0 – video on karyotypes. KARYOTYPE.

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Human Heredity

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  1. Human Heredity http://www.youtube.com/watch?v=hNMYV213xu0 – video on karyotypes

  2. KARYOTYPE

  3. Sordaria fimicola is a species of microscopicfungus. It is commonly found in the feces of herbivores. Sordaria fimicola is often used in introductory biology and mycology labs because it is easy to grow on nutrient agar in dish cultures. The genus Sordaria, closely related to Neurospora and Podospora, is a member of the large class Pyrenomycetes, or flask-fungi. The natural habitat of the three species of Sordaria that have been the principal subjects in genetic studies is dung of herbivorous animals. The species S. fimicola is common and worldwide in distribution. The species of Sordaria are similar morphologically, producing black perithecia containing asci with eight dark ascospores in a linear arrangement. These species share a number of characteristics that are advantageous for genetic studies. They all have a short life cycle, usually 7–12 days, and are easily grown in culture. Most species are self-fertile and each strain is isogenic. All kinds of mutants are easily induced and readily obtainable with particular ascospore color mutants. These visual mutants aid in tetrad analysis, especially in analysis of intragenic recombination.[1] The most common form of S. fimicola is a dark brown. Certain mutants are grey or tan. A common experiment for an introductory biology lab class is to cross one of the mutant types with a wild type and observe the ratio of coloring in the offspring. This experiment illustrates the concepts of genetic inheritance in a haploid organism. The eight ascospores are produced inside an ascus. Sordaria squashes can give us information about crossing over during meiosis. If no crossing over then there is a 4:4 pattern. 4 black spores, and 4 tan spores all lined up. If crossing over does occur there is a 2:2:2:2 pattern visible, or a 2:4:2 pattern

  4. What makes us human? • To analyze chromosomes, cell biologist photograph cells in mitosis, when the chromosomes are fully condensed and easy to see. • Biologists then cut out the chromosomes and group them together in pairs. • A picture of chromosomes arranged this way is known as a KARYOTYPE.

  5. Human Karyotype

  6. What Can Our Chromosomes Tell Us? • We can learn a lot by looking at chromosomes! They can tell us everything from the likelihood that an unborn baby will have a genetic disorder to whether a person will be male or female. Scientists often analyze chromosomes in prenatal testing and in diagnosing specific diseases. Follow the links to find out what we can learn from our chromosomes.

  7. Making a Karyotype • A karyotype is an organized profile of a person's chromosomes. In a karyotype, chromosomes are arranged and numbered by size, from largest to smallest. This arrangement helps scientists quickly identify chromosomal alterations that may result in a genetic disorder.

  8. Using Karyotypes to Predict Genetic Disorders • A normal human karyotype has 46 chromosomes: 22 pairs of autosomes and 2 sex chromosomes. • What happens when a person has something different, such as: • Too many or too few chromosomes? • Missing pieces of chromosomes? • Mixed up pieces of chromosomes?

  9. Too many or too few chromosomes • To understand how our cells might end up with too many or too few chromosomes, we need to know how the cells normally get 46 chromosomes.

  10. Nondisjunction Homologous pair fails to separate in Meiosis I, or sister chromatids fail to separate in Meiosis II.

  11. EngageGenetic Disorders • Patau Syndrome • Edward Syndrome • Klinfelter’s Syndrome • Turner Syndrome • Super Male Syndrome • Super Female Syndrome • Down’s Syndrome

  12. Geneticists Wanted • WANTED: Very intelligent scientists to help figure out what is wrong with these children? Karyotype printable worksheets for activity http://www.google.com/imgres?imgurl=http://www.biologycorner.com/worksheets/karyotype/karyotype-female.gif&imgrefurl=http://www.biologycorner.com/worksheets/karyotype/chromosomestudy-teacher.html&usg=__Tm3uv0lCTIgozDBpZuNOZmzTcd8=&h=720&w=650&sz=32&hl=en&start=12&um=1&itbs=1&tbnid=tzRP25VHPwJTqM:&tbnh=140&tbnw=126&prev=/images%3Fq%3Dkaryotype%26um%3D1%26hl%3Den%26sa%3DX%26tbs%3Disch:1

  13. Background: • Mr. and Mrs. Raider are deeply worried about their child who seems to be developing at a slower rate. They are concerned for the child’s health just like any other parent and are asking you for help?

  14. What to hand in: • You will be given a karyotype of the child to determine if they have a genetic disorder and what kind. • You will then write a dialogue that could have taken place between the geneticist and the parents of the child. • Dialogue should be one page • Dialogue should include: -What the is the disease? / How this happened? -What are the symptoms? -What is the life expectancy? -What they can do as parents? -Is there a cure?

  15. Mothers in early 20s 1 in 1,500 births • Mothers over 35 1 in 70 births • Mothers over 45 1 in 25 births

  16. 47, XX or XY, +13 • serious eye, brain, circulatory defects as well as cleft palate. 1:5000 live births. Children rarely live more than a few months. • Patau Syndrome

  17. Edward Syndrome • almost every organ system affected 1:10,000 live births. Children with full Trisomy 18 generally do not live more than a few months.

  18. Klinefelter’s Syndrome • Male sex organs; unusually small testes, sterile. Breast enlargement and other feminine body characteristics. Normal intelligence.

  19. Turner Syndrome • the ONLY viable monosomy

  20. 1 in 3,000 female births • Sterile females

  21. Jacobs (XYY) 1 in 1000 male births Tall Lower mental ability Tendency for aggressiveness

  22. Super Male and Super Female • - Has an XXX- Fertile females with normal intelligence • Has an XYY- Tall male with heavy acne- Some tendency to mental retardation • Aggressive tendency

  23. Normal Female

  24. Normal Male

  25. Explain

  26. Questions • How many chromosomes come from your Father? • How many chromosomes come from your Mother? • What are chromosome pairs 1-22 called? • What is chromosome pair 23 called?

  27. Disorders • Name 3-4 diseases caused by a chromosomal abnormality. • What most often causes this abnormal number of chromosomes?

  28. Terms to Know • If either of these gametes unites with another during fertilization, the result is ________________ (any abnormal chromosome number) • A _____________cell has one extra chromosome (2n +1). Down syndrome(trisomy 21), Klinefelters (XXY), Triple X (XXX), Jacobs (XYY) • A ___________ cell has one missing chromosome (2n - 1) Turners Syndrome Aneuploidy Trisomy Monosomy

  29. Elaborate • Draw pedigrees from the given problems.

  30. Engage Sex-Linked Recessive – Hemophilia “The Royal Disease” Read the short story Alexis: The Prince Who Had Hemophilia –by:-Kelley, Laureen A.Set in the early 1900s, this is the story of the youngest child of Tsar Nicholas II of Russia, last Tsar of Russia. The story includes how Alexis's hemophilia influenced the course of events in Russia that led to the Russian Revolution

  31. Some History • Hemophilia has played an important role in Europe's history • The disease began to crop up in Great Britain's Queen Victoria’s children • It became known as the "Royal disease" because it spread to the royal families of Europe through Victoria's descendants

  32. How it Spread • it spread through the Royal Houses of Europe as monarchs arranged marriages to consolidate political alliances. • We can trace the appearance of hemophilia as it popped up in Spain, Russia, and Prussia by looking at the family tree.

  33. The Royal Family Tree

  34. Queen Victoria's son Leopold's Family • His daughter, Alice of Athlone, had one hemophilic son (Rupert) and two other children -- a boy and a girl -- whose status is unknown. • What is the chance that her other son was hemophilic? • What is the probability that her daughter was a carrier? hemophiliac?

  35. The Spanish Connection • Now for the Spanish connection: Victoria's youngest child, Beatrice, gave birth to one daughter, one normal son, and two hemophilic sons. • Looking at the pedigree of the royal family, identify which of Beatrice's children received the hemophilic gene; why can you make this conclusion? Notice that Beatrice's daughter, Eugenie, married King Alfonso XIII of Spain and had six children, one of whom was the father of Juan Carlos, the current King of Spain. • Would you predict that Juan Carlos was normal, a carrier, or a hemophilic?

  36. German and Russian Influences

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