Science916- Lab Write up
Title: Observing Human Characteristics
Problem: What discrete variations are among my classmates?
Background information: Discrete variations are variations with a limited number of possibilities for
a trait. For instance, if your hairline is smooth or pointed, if your fingers are hairy or smooth, or
weather or not you can roll your tongue.
Hypothesis: I think that there will be a fairly even number of people with each trait in my class. I
think that the tongue rolling trait will be an exception, and be fairly rare, though.
Design: I’ll be seeing which of my classmates has which trait including hair on fingers, ability to roll
the tongue, if the thumb bends backwards, if the earlobe is attached or not, and if their hairline is
smooth or pointed.
MV: The different traits listed above
RV: A better understanding on my part of the different types of discrete variations
CV: I’ll ask the same amount of questions to each person, not asking 5 people about rolling their
tongue and only 2 people about their hairline.
Pre-Lab work: See the lab write up
Materials and equipment: pencil and paper for recording data
Procedure:
1. Familiarize myself with the different forms of each trait
2. Poll the students in my class to see who has what trait
3. Record data
4. Plot results in a bar graph
Data:
Middigital
Hair
Hair
No
Hair
6/30
24/30
Tongue
Can
Roll
19/31
Thumb
Can’t Bent
roll
Back
12/31 26/31
Earlobe
Hairline
Straight Attached Detached Smooth
Pointed
5/31
7/31
6/31
25/31
24/31
Science916- Lab Write up
Analyse:
30
25
20
15
Has Trait
Doesn’t have trate
10
5
0
Middigital
hair
Tongue
can roll
Attached
earlobe
Pointed
hairline
Thumb can
bend back
Conclusion: My hypothesis was incorrect when I said “I think that there will be a fairly even number
of people with each trait in my class.” And also when I said that I thought that tongue rolling trait
would be rare, because there are more people who CAN roll their tongues then the people who can’t.
In answer to the problem, all of the above discrete variations appear in my class among different
people.
Questions:
1. Are some forms of a trait more common than others? Yes, In most of the traits, there either is or
isn’t the trait in different people, and the numbers of people with the trait and the numbers of people
without it are all very different from each other.
2. What can you conclude about the way traits vary among your class members? Why do you think
some students show one form of a trait while others show a different form? The traits vary greatly
among my class. I think different students show different traits because we ARE different, and we
have different genetic traits and families.
3. Do you think most traits are continuous or discrete? I think most traits are discrete. There are only
two options for each trait, not a range of intermediate options.
Bibliography: I got all of my information from the lesson and the textbook (Science Focus 9)
Dermal Ridge Counts:
1. Which one of the three kinds of fingerprints do you have? I have Archs.
2. What is your dermal ridge count? How does it compare with the counts of other students? Since I
have Arch fingerprints, my dermal ridge count is 0.