Chapter 8 Quiz 1

1
Class Topics
Title Biology 1/31/07
Objectives

• To continue learning about Mendelian genetics and
  learn about some of the aberrations to Mendelian
  genetics

• Chapter 8 Quiz 1
• Chapter 8 Beyond Mendel
• Incomplete dominance
• Codominance
• Dihybrid crosses
• For every complex problem, there is a solution
  that is simple, neat, and wrong.
• H.L. Mencken

Monday, January 20, 2014 1105 PM
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Class Assignments
By When
What

• Chapter 8 Quiz 1 1/31/07
• Genetics Problems 2/2/07
• Read 170-178 2/2/07
• Chapter 8 Quiz 2 2/6/07
• Due this class period
• Due next class period
• Due in the future

3
Grade Sheet
2A p. 157 (5 pts.)
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Postquiz Activities

• Hand in quiz
• Read 170-178
• Work on Genetics Problems W.S.
• Correct homework

5
Incomplete dominance

• In some organisms neither allele is dominant
• Blending of traits
• Snapdragons - red, white, and pink
• P ___ x ___
• F1
• Pheno
• Geno
• F2
• Pheno
• Geno

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From http//www.synapses.co.uk/genetics/codom.ht
ml
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Codominance

• Both traits are dominant and shown equally
• Roan cattle - both red hairs and white hairs
• 3 phenotypes - red, white, roan
• Erminette chickens - both black and white
  feathers
• 3 phenotypes - black, white, and black and white

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http//tidepool.st.usm.edu/crswr/codominance.html
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Dihybrid cross

• Crossing two traits
• Green and Tall plant (GgTT) x with yellow and
  Tall plant (ggTt)
• FOIL - GgTT
• FOIL - ggTt
• 16 box punnett square

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Dihybrid Cross

• GgTT x ggTt

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Results

• F1 - Pheno
• Green/Tall
• Green/short
• yellow/Tall
• yellow/short
• What if there were 160 of these seeds planted?
  How many of each type would there be?

12
Video Reviews

• Investigating Mendels law of segregation
• Using terms of Modern Genetics to explain
  Mendels work