Genetics is extremely interesting. Before we started this unit, I had no idea how genetic traits were really decided. I knew that my sister looked like my dad, and that I looked like my mom. My brother, on the other hand was kind of a mix between both of them. However, genetics is more than just what color your skin, your hair, and your eyes are.
By observing some simple features of my family members, I discovered some interesting information about my family. Everyone in my family has unattached earlobes, which doesn’t come as a surprise because attached earlobes is a recessive gene. However, I can’t say for certain what the genotype is, because we could either be homozygous dominant or heterozygous. It is more probable that everyone in my family is homozygous dominant, since no one has attached ear lobes, but it’s not definite.
The information I found when I asked every member of my family to roll their tongue was very interesting. When I asked my mom, she had no problem with this task (like me.) However, my brother, sister, and dad tried, tried, and failed… From this information, I know that in order for me to be able to roll my tongue, my dad, my sister, and my brother must be homozygous recessive because tongue roll is a dominant gene. My mom and I are both heterozygous because some of my siblings can roll their tongues, and some can’t.
For the hitchhikers thumb task, my results were similar to the information found in the tongue roll test. My dad, sister, and brother all had non-hitchhikers thumbs, while my mom and I had hitchhikers thumbs. Therefore, my dad, sister, and brother must be homozygous dominant, since hitchhikers thumb is a recessive gene. Thus my mom and I are heterozygous.
For the widow’s peak test, my results were slightly different. My dad and my sister have widow peaks, while my brother, mom and I don’t have widow’s peak. Therefore, since widow’s peak is dominant, my dad and sister are heterozygous, thus my brother, mom, and I are homozygous recessive.
It was interesting to see that genetics goes further than things like the color of your skin, eyes, and hair. My mother and I shared the same results, and we also look very similar. My dad and my sister also look alike, and they also share the same results. However, my brother shared more of the same results with my father, but he looks more like my mother than my father.
On another note, I’ve noticed that a lot of my male family members have cleft chins. All the males on my mom side of the family have cleft chins (which form when they are about sixteen.) My father has a cleft chin, while I’m pretty sure his dad and his brother don’t have cleft chins. Cleft chin is a recessive gene. For this reason, I believe that my dad is homozygous recessive, and my mom is heterozygous. Therefore, I think once my brother (12) matures, he will develop a cleft chin.
*note to reader: sister referred to in this post is my older sister. I have a younger sister, unfortunately though she was unavailable for testing.
Sources (gene dominant/recessive):
