Ch' 9: Patterns of Inheritance

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Ch. 9 Patterns of Inheritance
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The language of genetics

• Definitions
• trait - genotype
• allele - phenotype
• hybridization - dominant allele
• monohybrid cross - recessive allele
• P generation - homozygous
• F1 generation - heterozygous
• F2 generation - complete dominance

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Who is Gregor Mendel?

• Before Mendel - there was the Blending Theory.
• Particulate theory of heredity
• The scientific method allowed Mendel to analyze
  his results and make conclusions.

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How did he do it?

• Clearly visible traits, each of which has 2
  alternate forms
• flower color
• flower position
• seed color
• seed shape
• pod shape
• pod color
• stem length

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How did he do it?

• He started his experiments with true-breeding
  plant varieties (P generation). He hybridized
  them in experimental crosses to get the F1
  generation.
• He then allowed the F1 generation to
  self-pollinate to produce the F2 generation.
• He observed the phenotype of selected traits.

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RepetitionRepetitionRepetition

• Mendel repeated these experiments with the other
  6 characteristics.
• What did he find?????????????

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Monohybrid Testcrosses
gametes
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Dihybrid Testcrosses

• Gametes
• F1 generation
• F2 generation

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Its the Law!!!!

• Law of Probability

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Its really not that simple.

• The relationship between genotype and phenotype
  is rarely simple.
• Incomplete dominance
• know examples covered in class
• Codominance
• multiple alleles
• know examples covered in class
• Sex-linked traits
• know examples covered in class
• Sex-influenced traits
• know examples covered in class

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Its really not that simple.

• Nature vs. Nuture