Dominant and Recessive Traits
What are traits? Physical Traits Acquired Traits Behavioral 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
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 individual’s observable traits What people can SEE when they look at you
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
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)
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
Detached (EE, Ee) or attached (ee) Earlobes http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
Can Tongue Roll (TT, Tt) or Can’t (tt) http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
Dimples (DD, Dd) No Dimples (dd) http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
Right (RR, Rr) or Left (rr) handed?
Freckles (FF, Ff) No Freckles (ff) http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
Curly (HH, Hh) or Straight (hh) http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
Cleft Chin (CC, Cc) or No Cleft (cc)
Allergies (AA, Aa) or No Allergies (aa)
Hand Clasp Right over Left? http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
Normal (BB, Bb) Color Blindness (bb) Can you see the number inside the circle? If you cannot, you may be colorblind
Widow’s Peak (WW, Ww) or Straight (ww) http://teach.genetics.utah.edu/content/heredity/docs/InventoryComplete.pdf
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 6th grade?