Single-Factor Punnett Square Notes

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Single-Factor Punnett Square Notes
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Punnett Square

• A diagram that can be used to predict the gene
  combinations that might result from a cross

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Basic Problems

• T Tall
• t short
• Tt x TT

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T T
TT
T t
TT
Tt
Tt
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TT Tt tt Genotypic
Ratio_____________ Phenotypic Ratio_____________
4 0
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Basic Problems

• T Tall
• t short
• Tt x Tt

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T t
TT
T t
Tt
Tt
tt
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TT Tt tt Genotypic
Ratio_____________ Phenotypic Ratio_____________
3 1
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Word Problems

• A Axial flowers
• a terminal flowers
• Cross homozygous axial plant with a terminal
  plant.
• __________ X _________

AA
aa
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Basic Problems

• A axial
• a terminal
• AA x aa

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a a
Aa
A A
Aa
Aa
Aa
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AA Aa aa Genotypic
Ratio_____________ Phenotypic Ratio_____________
4 0
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Word Problems

• A Axial flowers
• a terminal flowers
• Cross 2 plants that are heterozygous for axial
  flowers.
• __________ X _________

Aa Aa
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Basic Problems

• A axial
• a terminal
• Aa x Aa

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A a
AA
A a
Aa
Aa
aa
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AA Aa aa Genotypic
Ratio_____________ Phenotypic Ratio_____________
3 1
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Backwards Problems

• G Green pods
• g yellow pods
• ¾ of the plants produced by a cross between 2
  unknown pea plants have green pods and ¼ have
  yellow pods. What are the genotypes of the
  parent plants?
• __________ X _________

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G

G
G
gg
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(No Transcript)
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Parents Genotypes are.

• Gg X Gg

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Backwards Problems

• G Green pods
• g yellow pods
• What cross would result in ½ of the offspring
  having green pods and ½ of the offspring having
  yellow pods?
• __________ X _________

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G
G
gg
gg
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(No Transcript)
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Parents Genotypes are.

• Gg X gg