Instructions
Overview
 
Problem 1: Tongue Rolling
Tongue Rolling
 
Problem 2: Eye Colour
Eye Colour
 
Problem 3: Diabetes
Diabetes
 
Problem 4: Blood Type
Blood Type
 
Quiz
Quiz
EYE COLOUR

The colour of your eyes is caused by pigment molecules in the iris, the ring that surrounds the black pupil in the centre.

While eye colour is actually more complicated than the this, dark eyes (such as brown or black) is dominant (E) and light eyes (such as blue or grey) is recessive (e).

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A father and a mother both have brown eyes. Their two sons have blue eyes and their two daughters have brown eyes. One daughter carries the gene for blue eyes, the other doesn't.
PEDIGREE




      
homozygous dominant male

    
heterozygous/carrier male

    
homozygous recessive male

    
homozygous dominant female

    
heterozygous/carrier female

    
homozygous recessive female

    
    
homozygous dominant genotype

    
    
heterozygous/carrier genotype

    
    
homozygous recessesive genotype

  
generations

QUESTIONS
  1. Type the cross for the parents (father x mother).

      


  2. Is the mother homozygous or heterozygous?

      


  3. What percent of the children are homozygous recessives?

      


  4. If one son gets married and all his children have brown eyes, what must the genotype of his wife be?

      


  5. How could the cross for the parents (father x mother) be written using the "dash" technique for unknown genes?

      


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