Dominant and Recessive Traits

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• Dominant and Recessive Traits

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What are traits?

• Physical Traits
• Can be seen by others
• Eye color, hair color, height, left handed
• Acquired Traits
• Learned skills
• Playing a sport, riding a bike, playing a musical
  instrument
• Behavioral Traits
• Instinctual actions
• Nest building and migration

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Review Terms Used in Modern Genetics

• Genotype
• The particular alleles (genes) an individual
  carries
• They are inherited from your biological parents
• Genes control your traits
• Phenotype
• An individuals observable traits
• What people can SEE when they look at you

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Review Terms Used in Modern Genetics

• An individual with non-identical alleles of a
  gene is heterozygous for that gene
• Examples Bb, Tt, Aa
• An individual with identical alleles of a gene is
  homozygous for that gene
• Examples BB or bb, TT or tt

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Terms Used in Modern Genetics

• An allele is dominant if its effect masks the
  effect of a recessive allele paired with it
• Capital letters (A) signify dominant alleles
  lowercase letters (a) signify recessive alleles
• Homozygous dominant (AA)
• Homozygous recessive (aa)
• Heterozygous (Aa)

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What traits do you have?

• We will go through the most common traits that
  people have
• On your sheet, record if you have the mentioned
  trait or not
• You may have to ask your neighbor for help ?

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Detached (EE, Ee) or attached (ee) Earlobes
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Can Tongue Roll (TT, Tt) or Cant (tt)
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Dimples (DD, Dd) No Dimples (dd)
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Right (RR, Rr) or Left (rr) handed?
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Freckles (FF, Ff) No Freckles (ff)
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Curly (HH, Hh) or Straight (hh)
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Cleft Chin (CC, Cc) or No Cleft (cc)
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Allergies (AA, Aa) or No Allergies (aa)
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Hand Clasp Right over Left?
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Normal (BB, Bb) Color Blindness (bb)
Can you see the number inside the circle? If you
cannot, you may be colorblind
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Widows Peak (WW, Ww) or Straight (ww)
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Data

• We will now record our class data and graph our
  results
• Does our data support which genes are dominant
  and which genes are recessive?
• What about the whole 7th grade?