Download Sample 2

Heredity Study
Biology
5th Hour 2012
Abstract
The traits that we tested against our family were the taste of PTC paper, if they have hair on
their second digit of their finger, and if they have unattached or attached earlobes, and if they
could roll their tongue in anyway. We have a big family and didn’t get around to testing all of
the traits that we wanted to. There were a ton of people that couldn’t taste the PTC paper.
There were very few who could taste it. Almost everybody in my family has unattached
earlobes. Only four people that we tested had attached earlobes, and most of them were
married into the family. Out of the thirty people that we tested only six of them could not roll
their tongue. Most of our family can roll their tongue either hot dog style or clover-leaf style.
When we tested for hair on the second digit of their finger, we concluded that almost every guy
has hair there and barely and girls have hair on their fingers. Our family has the trait where they
have lots of hair except for on their heads, so we predicted that it would turn out to be like
that. As of the world population, we think our family is right there with the rest of the world. It
looks as if our family got the dominant trait of having unattached earlobes. There were very
few that got the recessive trait from their other genes. Almost everybody was able to roll their
tongue and it was about even of how many boys and girls were able to. Errors could have gone
wrong by them not being a blood-related relative.
Introduction
What do you think genetic means? Genetics is the study of heredity. Heredity is the
transfer of characteristics from the parent to their offspring. Hereditary traits are made by
specific genes. The offspring gets one trait from the mother which is the egg, and one part from
the dad, which is his sperm. When they reproduce, the genes segregate and go into different
gametes. Your hair color, height, and chance of getting certain diseases are based on heredity.
If it runs in your family you have a chance of getting that disease.
Background
Tasting of PTC paper:
The percentage of people who can taste PTC paper is 70%; the percent that cannot taste
the PTC paper is 30%. If you can taste the paper, it shows a dominant pattern of inheritance.
The ability to taste PTC goes with the ability to taste other bitter foods that do not happen
naturally. They usually have toxins in them.
The two commons forms are tasting an allele, and a non-tasting allele. The shape of a
receptor protein determines how strong it can stick to the PTC. Everybody has two copies of
genes, so whether you can taste the paper depends on if people find the taste bitter, or a little
bit bitter, or really no taste at all. http://en.wikipedia.org/wiki/Phenylthiocarbamide
Attached or Unattached Earlobes:
Having an attached earlobe is recessive, and having an unattached earlobe is dominant.
Some people have one attached earlobe and the other ear is unattached. How does this
happen? Well, one ear might have followed the dominant gene and the other one followed the
recessive one.
Another way to have this happen is if you are a chimera. A chimera is a person who has
two groups of cells in them. Each cell has their own set of DNA. There is a big difference
between the two sets of DNA. 25% of people have attached earlobes and 75% of people have
free earlobes. http://www.thetech.org/genetics/ask.php?id=190
Ability to Roll Tongue:
The ability to roll your tongue is dominant over not being able to roll your tongue. 65%85% of people are able to roll their tongue. There are more females that can do it compared to
males. Tongue rolling is a two-allele trait. Each gene has two alleles.
We all know that genes make proteins. There could be a gene somewhere in the
genome that is able to block the action of the tongue rolling proteins made by the tongue
rolling genes. That affects if you will be able to roll your tongue or not. They say that if you are
able to roll your tongue, you could have a modifier gene.
http://www.brighthub.com/science/genetics/articles/35598.aspx
Mid-Digit Hair:
Mid –digit hair genetics are determined by autosomes. Having hair on your mid-digit
finger is said to be dominant. D0, D1, D2, D3, D4, are examples of the five multiple alleles. This
refers to the number of fingers having mid-digit hair. If you have D0D0 means that it is the
absence of mid-digit hair.
40% of Japanese people, and 70% of Germans have hair on their middle digit finger.
They took a survey in Japan testing about 7,500 people and at least 24% of those people had
hair on their mid-digit finger. http://udel.edu/~mcdonald/mythdigithair.html
Methods
Hypothesis: We think that less people will be able to taste the P.T.C. paper more than
people who will be able to. More people will have unattached earlobes. Sam thinks that almost
everybody will be able to roll their tongue in some way. My opinion is different. I think that
more people won’t be able to roll their tongue at all. We both think that there will be a lot of
people who will have hair on the second digit finger. We highly doubt that there will be
anybody in our family who won’t have hair on their second digit finger.
Procedure: We plan on testing our traits by going to each of their houses or calling them on
the phone. For each one of the houses we visit, we will be looking at all the traits that they
have. If we can’t go to their house we aren’t going to have them taste the P.T.C. paper because
then you couldn’t test if they could taste it or not. If we end up calling them on the phone, we
will have them test the easier ones. They can look in a mirror for themselves to determine
which traits they have.
Controlled: The controlled variable will be the blood-related relatives. We will compare
these trait results to the nation’s results. We will compare these results to the non-blood
relatives that are part of our family by marriage.
Variables: Our variable will be the relatives that are not blood-related to us. Their results will
probably differ from the relatives that are blood-related. If one of our blood-related cousins is
pregnant, she might not be able to taste the paper as well as other family members should be.
Family:
Taste of PTC
paper:
Free or Attached
Earlobes:
Ability to Roll
Tongue:
Hair on 2nd
Digit Finger:
Blood
related/Married
in
Grandma
Jim
Christine
Kieran
Alex
Joey
Keith
Jeremy
Cork
Mikayla
Connor
Christina
Janai
Mo
Bone
Jason
Lindsay
Brad
Cassie
Ryan
Mike
Jill
Sam
Max
T.J.
Chris
Judy
Ben
Ryan
Eryn
Yes
didn't test
Yes
No
Yes
Yes
No
No
Yes
No
No
didn't test
No
No
No
didn't test
didn't test
didn't test
didn't test
didn't test
No
Yes
Yes
Yes
No
No
Yes
No
Yes
Yes
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Attached
Unattached
Attached
Unattached
Unattached
Attached
Attached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Unattached
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
No
Yes
No
Yes
No
Yes
Yes
No
Yes
Yes
No
Yes
No
No
No
No
blood related
blood related
married in
blood related
blood related
blood related
blood related
blood related
blood related
blood related
blood related
married in
married in
blood related
married in
blood related
married in
blood related
blood related
married in
blood related
married in
blood related
blood related
blood related
blood related
married in
blood related
blood related
blood related
4 Attached, 26
Unattached
13% attached, 87%
Unattached
75% Unattached,
25% Attached
24 can roll, 6
can't roll
80% can roll,
20% can't
85% can roll,
15% can't
Total
Amount:
11 Yes, 12
No
48% yes,
% of each 52% no
70% can,
World % 30% can't
18 Do, 12 Don't
60% Do, 40%
Don't
Germans: 70% do, 30% don't
Japanese: 40% do, 60% don't
Discussion
Even if the people are married in they still have a lot of the same traits. There were only a few
that didn’t have unattached earlobes. Like Christina is married in and she has attached earlobes
so her daughter, Mikayla also has attached. A lot of our family members who are married in
have no hair on the second digit of their finger. A lot of the people that are married into our
family are girls because we have eight uncles and only two real aunts. The world percentage is
way higher for people who can taste PTC paper than people who can in my family. My family’s
percent is closer than the world’s percentage. For unattached earlobes the percentages are a
lot alike. More people have unattached earlobes than attached earlobes in my family and in the
world’s population. The percentages are very close in being able to roll your tongue. Our
family’s percent is 80% and the world’s is 85%. Since we couldn’t find any world percentages for
having hair on your second digit finger, I will compare our family’s results to the Germans, and
the Japanese. Our family’s percentages are really close to the German’s but not the Japanese.
We are closer to the German’s more than the Japanese.
REFERENCES
http://www.koshland-science-museum.org/teachers/Inventory_of_Your_Traits.pdf
http://www.brighthub.com/science/genetics/articles/35598.aspx
http://udel.edu/~mcdonald/mythdigithair.html
http://library.thinkquest.org/19037/heredity.html
http://dictionary.reference.com/browse/genetics
http://.omg-facts.com/view/Facts/14982
http://www.uni.edu/walsh/genetics.html
http://en.wikipedia.org/wiki/Phenylthiocarbamide