Name:



Name: ___________________________

What is your Genotype?

Can you determine which genes you have simply by looking in the mirror? From your eye color to how you fold your hands, the genes you inherited from each of your parents determine certain physical features. More than 2000 traits have been decoded in the human genome. In this activity, you will just determine a few of your genotypic traits. Observing phenotypes will only tell us whether or not the trait you possess is dominant or recessive (in a few cases we will also be able to determine if you are heterozygous for the trait). Use a capital letter to represent a dominant trait and a lower case letter to represent a recessive trait on the chart under the heading “Your genotype.” Under possible genotypes write the possible combinations (for example if you have a dominant trait you can either be DD or Dd. If you are recessive you can only be rr).

| |Dominant Phenotypic Trait | |Recessive Phenotypic Trait |Your genotype |Possible genotypes |

|1 |Pigmented skin, eyes, hair |P |Albino- no pigment | | |

|2 |Piebald- skin and hair spotted with white |F |Uniform color on skin and hair | | |

| |blotches | | | | |

|3 |Dark hair |D |Light hair | | |

|4 |Non-red hair |R |Red hair | | |

|5 |Curly Hair (**WAVY=Cc) |C |Straight hair | | |

|6 |Freckles |F |No freckles | | |

|7 |Widow’s Peak on forehead |W |Straight forehead hairline | | |

|8 |Hair whorl- clockwise |W |Hair worl- counter clockwise | | |

|9 |Free ear lobes |L |Attached earlobes | | |

|10 |Ability to roll tongue |R |Can’t roll tongue | | |

|11 |Brown eyes |B |Blue, green, hazel or grey eyes | | |

|12 |Normal Vision for distant objects |V |Nearsightedness (trouble seeing far | | |

| | | |away) | | |

|13 |Farsighted (trouble seeing things up close) |F |Normal Vision for close up | | |

|14 |Cataract (white spots on eye) |C |No cataracts | | |

|15 |Colored vision |V |Colorblindness | | |

|16 |Extra fingers or toes |T |Normal # of fingers or toes | | |

|17 |Dimples on cheeks |D |No dimples on cheeks | | |

|18 |No hair on middle knuckle of the ring finger |K |Hair on middle knuckle of ring finger| | |

|19 |Non bent thumb |T |Hitchhiker’s thumb | | |

|20 |Bent little finger |B |Straight little finger | | |

Analysis Questions

Use the variables from the chart on the front to answer the questions below.

1. Two people with brown hair have a red haired child. What must the parent’s gentoypes have been? ____ Are they both heterozygous or homozygous? _____________

Fill in the Punnet square to explain your answer.

2. One parent has dimples, but the other parent does not. Will their children have dimples? Fill in both Punnet squares to answer the question (Remember one parent may be homozygous dominant or heterozygous dominant)

3. One sister had freckles. One sister does not have freckles. What are the two possible genotype combinations of the parents? Use the Punnet squares to the left.

4. Sally is nearsighted. Her father is not nearsighted,

but her mother is. Her sister is not nearsighted. What is the

genotype of her father? Fill in the Punnet square to the

right.

5. Explain how two parents with brown eyes can have a blue eyed baby.

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6. One parent is heterozygous for tongue rolling, the other can not tongue roll. Write the ratios of their children that can roll the tongue and those that cannot roll the tongue and fill in the Punnet square to support your answer. Ratio: ____________

7. Of 8 children, 6 have piebald spotting on their skin, the other two

children do not. Draw a Punnet square representing the genotypes

of parents that would most likely produce this ratio.

8. Two parents with free ear lobes have one adopted child and one child of their own. One has attached ear lobes and one does not. Is it possible to tell which one is adopted? (There are 3 possible genotypical combos for the parents)

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