Human Genes
CIM Lab Opportunity
• Before you begin your investigation you will
check your understanding of
•
•
•
•
Genotypes
Phenotypes
Alleles
The possible combinations for each trait by filling
out the following table
Your Genes
Genetic
Trait
Ability to
roll
tongue
Type of
earlobe
Type of
thumb
Type of
hairline
Freckles
Dimples
Possible
Phenotypes
in
Population
Your
Phenotype
Alleles
Possible
Geneotypes in
Population
Your
Possible
Geneotype
Ability to roll tongue
Tongue Roller
Non-tongue Roller
Type of earlobe
Free Lobe
Attached Lobe
Type of thumb
Normal
Hitch Hikers
Type of hairline
No Widow’s Peak
Widow’s Peak
Type Freckles
Freckles
No Freckles
Dimples
Dimples
Your Genes
Genetic
Trait
Ability to
roll
tongue
Type of
earlobe
Type of
thumb
Type of
hairline
Freckles
Dimples
Possible
Phenotypes
in
Population
Your
Phenotype
Alleles
Possible
Geneotypes in
Population
Your
Possible
Geneotype
Part 1:
Background for Examining the Frequency of Each Trait in the
Population
Your CIM lab should begin
with a…
1. Title:
Write a title below that is specific and includes detail about
your investigation.
2.
Question:
Is the dominant trait in a population always more common
than the recessive?
3. Hypothesis:
Write your hypothesis below. Remember, a hypothesis
should be in the ‘If…, then….’ format, and should state a
relationship between your two variables.
Page 1
Page 2
Hint: do this page last.
Now you need to write your
Background Information A:
1.
Background Information
should explain the terms and
concepts you need to know to
understand your investigation.
2.
It should also explain the
reasoning that backs up your
hypothesis.
3.
The Background Information
should not contain the results
of your investigation (this
information will be discussed
in your conclusion).
Now you need to write your
Background Information B:
• This should be at least three
long paragraphs
• You need to demonstrate
that you have done
additional research online
besides what was done in
class.
Now you need to write your
Background Information C:
You should answer the following questions in your Background
Information:
•What is a trait?
•What is the difference between a phenotype and a genotype?
•What are alleles and where do they come from?
•What do we mean when we say a trait is dominant or recessive?
•How will we look at frequencies in our population?
•How do the above questions relate to your hypothesis?
•What you know about the individual trait(s) after doing online
research.
Part 2
Materials & Procedures
Materials
• We will not have many
materials for this lab but
you should list any that you
use.
Procedure A
Conduct a survey of at least
40 people in your school or
community to see what their
phenotype is for each of the
following 3 traits:
1.Widow’s Peak
2.Ability to roll tongue
3.One other trait of your choice
from the first page of your
handout.
Procedure B
• Remember to list your:
1. Independent variable
2. Dependent variable
3. Control variable(s)
Procedure C
•
Be sure that you give a detailed
description of the steps you used
to collect your data.
•
You should describe the
questions that you asked, how
you decided who to ask, any
determinations you made about
your populations, and difficulties
that you encountered in the
procedure.
•
Write your procedure in steps.
Include any drawings that
illustrate what procedure you
followed.
Part 3
Presenting the Data
Suzy Que
Billy Bob Smith
Dr. Suess
Matt Utterback
E. Stratton (mom)
Does not have
Choice Trait
Has Choice
Trait
Cannot Roll
Tongue
Can Roll
Tongue
Name
No Widow’s
peak
• You will need to
design a data
table on another
sheet of paper
that will include
the name of each
person you
surveyed and the
results of the
survey.
Widow’s Peak
Collecting Data
Percentage Calculations
For each of the 3 traits you
have collected data for
1.
widow’s/no widow’s peak,
2.
rolling/not rolling tongue,
3.
the trait of your choice),
Calculate the percentage of
individuals who show each
phenotype.
Widow's Peak
No
Widow's
Peak
30%
Widow's Peak
No Widow's Peak
Widow's
Peak
70%
What your page should look
similar to:
You may use multiple pages
Part 4
Analysis & Conclusion
Analysis & Conclusion A
• This is a key part of the investigation
where many students lose points in their
write-up.
• You need to explain clearly:
• What you found out in the investigation
(refer to specific data!)
• Whether it supports your hypothesis or not
• Why does this happen?
• What else might you discover about this
subject and how would you design an
investigation?
Analysis & Conclusion B
• Analyze the data and draw conclusions by answering the following questions.
1.From the data table on page one:
a)
Is a widow’s peak a dominant or recessive trait?
b)
Is widow’s peak or no widow’s peak the more common trait in the population?
2.From the data table on page one:
a)
Is the ability to roll the tongue a dominant or recessive trait?
b)
From the data you collected: is the ability to roll the tongue or the inability to roll the
tongue the more common trait in the population?
3.Fill in the blanks for the 3rd trait you surveyed.
a)
From the data table on page one: Is ___________________________ a dominant or
recessive trait?
b)
From the data you collected: Is ___________________________ or
___________________________the more common trait in the population?
Use these answers, and the questions above to help you write your conclusion.
Analysis & Conclusion C
• Is your hypothesis supported?
• From the analysis of your data, does dominance correlate with
frequency in the population (in other words, is the dominant
trait always the more common trait in the population)?
• Explain your answer using your data.
• Explain why this happens (this is a very important part of
your conclusion)!
• Explain two ways in which this investigation could be
improved or expanded upon to give more reliable data for
the human population.
Use these answers, and the questions above to help you write your conclusion.
Don’t forget!
• Works cited page at the end.
• The school’s media center’s
web pages can help you
create your works cited page.
• CIM Lab rubrics as the last
page.