Download B7 Quick Lab Genetic Variation in the Classroom Everyone has a

B7 Quick Lab
Genetic Variation in the Classroom
Everyone has a distinct set of traits. Some of these traits are hereditary. In this
activity, you will examine your own features to see what traits you have. You
will also calculate the frequency of particular traits in the classroom population.
Purpose
To observe various hereditary traits and calculate the frequency of traits in the
classroom population
Materials & Equipment
•
•
•
mirror
pencil or pen
paper
Procedure
1. Obtain or make a copy of Table B7.1, a data table for your genetic
trait survey.
2. Predict if you think the traits listed in the table will be distributed evenly
among the class, or if dominant traits will show up more often than
recessive traits.
3. Examine your features for each category of trait. Determine which traits
you have.
4. Your teacher will survey the class as a group to find out which traits
everyone has. Record the totals in your data table.
Questions
5. Calculate the frequency of each trait in the classroom population. Multiply
each frequency by 100 in order to calculate the percentage of each trait.
Record your calculations and the results in your table.
Number of students with trait
 100  _____%
Number of students in class
6. How do the results compare to your initial predictions?
7. For any category of trait, was the recessive trait more common than the
dominant trait? If so, hypothesize why this might be the case.
8. Did anyone have traits that were difficult to categorize as dominant or
recessive? Explain.
9. Did any two or more people in the class have the same set of traits
expressed in exactly the same way? Explain.
9780137053612
Copyright © 2011 Pearson Canada Inc.
This page may have been modified from its original.
BiologySource 11
Table B7.1 Genetic Trait Survey
Category
Dominant Trait
Number
Percentage
Recessive Trait
Hair
curliness
Naturally curly
hair
Naturally
straight hair
Cheek
dimples
Dimples on one
or both sides of
the face
No dimples on
either cheek
Chin
shape
Cleft in chin
No cleft in chin
Earlobes
Earlobes hang
free
Earlobes directly
attach to side of
head
Freckles
Freckles present
Freckles absent
Pointed
hairline
(widow’s
peak)
Hairline forms a
point
Straight hairline
Thumb
bending
Can bend thumb
forward or
backward
Cannot bend
thumb forward
or backward
Number
Percentage
(Art/ArtPlus Limited)
BiologySource 11
Copyright © 2011 Pearson Canada Inc.
9780137053612
This page may have been modified from its original.