1 / 15

Genetics

Genetics. Why do we look the way we do?. Inheritance of chromosomes. Egg + sperm  zygote. egg. meiosis. zygote. mitosis & development. fertilization. sperm. Inheritance of genes. On the chromosomes passed from Mom & Dad to offspring are genes may be same information

olaf
Download Presentation

Genetics

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. Genetics Why do we look the way we do?

  2. Inheritance of chromosomes • Egg + sperm  zygote egg meiosis zygote mitosis &development fertilization sperm

  3. Inheritance of genes • On the chromosomes passed from Mom & Dad to offspring are genes • may be same information • may be different information eye color (blue or brown?) eye color (blue or brown?)

  4. Effect of genes • Genes come in different versions • brown vs. blue eyes • brown vs. blonde hair • alleles

  5. Genes affect what you look like X bb BB Bb Bb Bb Bb Where did the blue eyes go??

  6. Genes affect what you look like… X bb Bb Bb Bb bb bb Why did the blue eyes stay??

  7. Genes affect what you look like… X Bb Bb bb BB or Bb BB or Bb BB or Bb Where did the blue eyes come from??

  8. What did we show here? • Genes come in “versions” • brown vs. blue eye color • alleles • Alleles are inherited separately from each parent • brown & blue eye colors are separate & do not blend • either havebrown or blueeyes, not a blend • Some alleles mask others • brown eye color masked blue

  9. eye color (blue?) hair color hair color How does this work? • Paired chromosomes have same kind of genes • but may be different alleles eye color (brown?)

  10. Traits are inherited as separate units • For each trait, an organism inherits 2 copies of a gene, 1 from each parent • a diploid organism inherits 1 set of chromosomes from each parent • diploid = 2 sets of chromosomes 1 from Mom homologous chromosomes 1 from Dad

  11. B B B b b b BB Bb bb Making gametes BB = brown eyes bb= blues eyes Bb= brown eyes  brown is dominant over blue  blue is recessive to brown Remember meiosis!

  12. B B B b b b BB Bb bb How do we say it? 2 of the same Homozygous BB = brown eyes bb= blues eyes homozygous dominant homozygous recessive 2 different Heterozygous Bb= brown eyes

  13. B b B b Punnett squares Bb x Bb male / sperm X BB Bb female / eggs Bb bb

  14. Genetics vs. appearance • There can be a difference between how an organism looks & its genetics • appearance or trait = phenotype • brown eyes vs. blue eyes • genetic makeup = genotype • BB, Bb, bb 2 people can have the same appearance but have different genetics: BB vs Bb

  15. B B B b BB Bb Genetics vs. appearance How were these brown eyes made? eye color (brown) eye color (brown) eye color (brown) eye color (blue) vs.

More Related