1 / 19

Karyotypes

Karyotypes. X Y. Several methods help map human chromosomes. A karyotype is a picture of all chromosomes in a cell. Human Karyotype. To analyze chromosomes, cells are photographed during mitosis when chromosomes are fully condensed and easy to see.

khaines
Download Presentation

Karyotypes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Karyotypes

  2. X Y Several methods help map human chromosomes. • A karyotype is a picture of all chromosomes in a cell.

  3. Human Karyotype • To analyze chromosomes, cells arephotographed during mitosis when chromosomes are fully condensed and easy to see. • Chromosomes are cut out of photographs and lined up with homologous chromosome and in order of largest to smallest. • Used to diagnose chromosomal disorders and determine gender.

  4. Karyotype : chromosomes are paired 1 from mom & 1 from dad 23 pairs 46 chromosomes 22 pairs – autosomes 1 pair sex chromosomes 46,XY Normal male

  5. Down syndrome: (Trisomy 21) 47, XX, 21+

  6. Is there something wrong on this karyotype?

  7. Human chromosomes • Let’s look at this again • There are 46 chromosomes (23 homologous pairs) in each somatic cell • 22pairsof autosomes • 1 pairofsex chromosomes • XX = Female, XY = Male • Karyotype- chromosomes are arranged according to shape and size Normal human karyotype

  8. Pedigrees Biology I

  9. Pedigrees analysis • Shows the analysis of inheritance in human families

  10. Most common signs and symbols used in pedigree analysis

  11. Inheritance patterns shown by a pedigree. • Basic patterns of inheritance • autosomal, recessive • autosomal, dominant • X-linked, recessive

  12. Autosomal recessive • e.g., PKU, Tay-Sachs, albinism • Autosomal dominant • e.g., Huntington’s Disease • X-linked recessive • e.g., color-blindness, hemophilia

  13. Autosomal disorders Autosomal disorders are more prevalent in certain geographic regions or cultures Recessive disorders • Cause: recessive alleles • Albinism, Cystic fibrosis, Sickle-cell anemia, Tay-Sachs disease • More common than dominant disorders Dominant disorders • Cause: dominant alleles • Dwarfism (Achondroplasia), Alzheimer’s disease, Huntington’s disease • Less common than recessive disorders

  14. Autosomal Recessive

  15. Autosomal Dominant

  16. X- linked Recessive What is the inheritance pattern? What is the genotype of III-1, III-2, and II-3? What are the odds that IV-5 would have an affected son?

  17. III-1 has 12 kids with an unaffected wife 8 sons - 1 affected 4 daughters - 2 affected Does he have reason to be concerned about paternity?

  18. Sample pedigree - cystic fibrosis What can we say about I-1 and I-2? What can we say about II-4 and II-5? What are the odds that III-5 is a carrier? What can we say about gene frequency?

More Related