1 / 27

Complex Inheritance

Complex Inheritance<br>

LbussieRHS
Télécharger la présentation

Complex Inheritance

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. Unit 5 Complex Inheritance

  2. Chromosome Structure • Chromosome– rod shaped structures made of DNA and proteins • Less tightly coiled DNA-proteincomplex – chromatin • DNA wrapped around histones –proteins that help maintain shape • Each half is called chromatid held together in middle by centromere

  3. Chromosome Numbers • Sex Chromosomes – determine the sex of organismXX=Female XY=Male (If you have a Y, you’re a guy) • Autosomes – all other chromosomes • 23 pairs – 46 chromosomes • 23 identical copies from each parent • Both copies are called homologous chromosomes

  4. Changes in chromosome numbers • Karyotype – photo of chromosomes • Extra chromosome, missing chromosomes, missing parts of chromosomes all result in disordersand diseases

  5. Diploid vs Haploid • Diploid (2n) – contains two sets of chromosomes • Haploid (n) – contains one set of chromosomes • Gametes – sperm and egg cells • Sperm cell (n) + egg cell (n) = zygote (2n)

  6. Meiosis • Cell division that halves the number of chromosomes when forming cells such as gametes (sex cells) • Reproduction of sex cells – sperm & egg • Four haploid (n) cells are produced • Crossing over can occur to increase genetic variation

  7. Prophase 1 • Nuclear envelope disappears • Crossing-over occurs – when homologous chromosomes exchange genetic material

  8. Metaphase 1 • Chromosomes move to center of cell

  9. Anaphase 1 • Homologous chromosomes split and move to opposite ends

  10. Telophase 1 • Nuclear envelope appears and spindle fibers disappears • Cytokinesis begins

  11. Prophase II • Nuclear envelope disappears

  12. Metaphase II • Chromosomes line up at the center

  13. Anaphase II • Centromeres divide • Chromatids move to different ends of the cell

  14. Telophase II • Nuclear envelope forms and spindle fibers disappear • Cytokinesis begins • Produces: 4 haploid cells

  15. Meiosis

  16. Mitosis Meiosis Both

  17. Genetics • Passing of characteristics - Heredity • Gregor Mendel – “Father of Genetics” • Used green pea plants • Study of heredity – Genetics

  18. Heredity Terms • Gregor Mendel – “Father of Genetics” • Alleles – refers to different versions of genes • Dominant – capital letter – if present, trait is expressed • Recessive – lower case letter – must have two to be expressed

  19. Heredity Terms • True “pure” breed – only 1 type of allele • Homozygous (TT, tt) • Hybrids – two different types of alleles • Heterozygous (Tt) • Phenotype – physical trait • Genotype – genetic make up

  20. Complex Patterns of Inheritance • Incomplete Dominance • Heterzygous phenotype is an intermediate of dominant and recessive • Red+white=pink • Co-dominance • Both alleles are expressed in the heterozygous condition

  21. Complex Patterns of Inheritance • Multiple Alleles • Blood groups in humans • A- & A+ • B- & B+ • AB- & AB+ • O- & O+ • Universal Donor • Universal Recipient

  22. Complex Patterns of Inheritance • Sex-Linked Traits • Traits controlled by genes located on X chromosomes • More common in males than females • Red-Green Color Blindness • Hemophilia – blood clotting disorder

  23. Pedigrees • Diagram that traces the inheritance of a trait through several generations

More Related