Chapter 9
Download
1 / 20

Chapter 9 - PowerPoint PPT Presentation


  • 177 Views
  • Uploaded on

Chapter 9. Genetics. 9.1 The Work of Gregor Mendel . Mendel – crossed pea plants to study and understand genetics Most pea plants self pollinate ( true breeding ) Mendel forced plants to cross pollinate (have 2 plants). Studied 7 traits of pea plants pg 176.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Chapter 9 ' - pepin


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Chapter 9

Chapter 9

Genetics


9 1 the work of gregor mendel
9.1 The Work of Gregor Mendel

  • Mendel – crossed pea plants to study and understand genetics

    • Most pea plants self pollinate (true breeding)

    • Mendel forced plants to cross pollinate (have 2 plants)



The f1 cross
The F1 Cross

  • First Filial (parent cross, produce the F1, then cross the F1 making an F2)

    • Law of segregation: Segregation of alleles occurs during the formation of gametes, sex cells.

    • Pg 177

    • Law of Independent Assortment – factors for individual characteristics are not connected. Assort independently of each other.


Came to 2 conclusions after the breeding
Came to 2 conclusions after the breeding

  • Genes, segment of DNA, occurs in pairs, controll heredity. Visual form called alleles. (noted as “factors”)

  • Found that some of the alleles are dominant and some are recessive.

    • Dominant trait always uppercase (TT, Tt)

    • Recessive always lowercase (tt)


9 2 probability and punnett squares
9.2 Probability and Punnett Squares

  • Punnett square – table representation of crossing alleles

    • TT or tt – homozygous – same alleles

    • Tt – heterozygous – different alleles

    • Phenotype – physical look, all tall (TT, Tt) have same phenotype.

    • Genotype – based on alleles. (TT, and Tt) are different now.


Probability
Probability

  • Penny = ½ = .50

  • A cross results in 787 pink flowers and 277 white flowers. If we cross the same P generation, the probability will be the same)


  • Dominant Recessive

  • Curled Up Nose Roman Nose

  • Clockwise Hair Whorl Counter-clockwise Hair Whorl

  • Can Roll Tongue Can't Roll Tongue

  • Widow's Peak No Widow's Peak

  • Facial Dimples No Facial Dimples

  • Able to taste PTC Unable to taste PTC

  • Earlobe hangs Earlobe attaches at base

  • Middigital hair (fingers) No middigital hair

  • No hitchhiker's thumb Hitchhiker's thumb

  • Tip of pinkie bends in Pinkie straight

  • Oval face Square face

  • Cleft chin no cleft chin

  • Broad eyebrow Slender eyebrow

  • Separated eyebrows Joined eyebrows

  • Long eyelashes Short eyelashes

  • Almond eyes Round eyes

  • Freckles No freckles

  • Wet-type earwax Dry-type earwax

  • Left thumb on top of

    interlocking fingers Right thumb on top of interlocking fingers






Summary of mendel s principles pg 272
Summary of Mendel’s Principles pg 272

  • Some alleles are neither dominant nor recessive, and many traits are controlled by multiples alleles or multiple genes.

  • Incomplete Dominance– when one allele is not necessarily dominant (red and white flowers produce pink)

  • Codominance – both alleles contribute to the phenotype.

  • Multiple alleles – within the population of the species there are more than just 2 types of alleles. Coloration in Rabbits

  • Polygenic Traits – having many genes, traits controlled by 2 or more genes. Skin color in humans.




Codominance
Codominance

  • Problems


Explore punnett squares
Explore Punnett Squares!!

  • http://www.geocities.com/CapeCanaveral/Hall/1410/lab-B-19.html



ad