Moore, Timothy
Moore, Timothy
Instructor: Mrs. Tammy Moore
Class: VHSG Online Biology
14 August 2010
EXPERIMENT 8.2
A Dihybrid Cross
Understanding how multiple traits are passed from one generation to another
Abstract
[What you will put here: Summarize the whole report in one, concise paragraph of about 100-200
words. You cannot write the abstract until after you've completed the report. Because it assumes that
you will speak to your conclusion or what you learned in brief.]
Introduction
[What you will put here: In this introduction, some background is provided for the reader
(sources are noted in the reference section at the end of the report).Typically, the introduction states the
problem to be solved or the experiment to be performed and explains its purpose and significance. It
also provides whatever background theory, previous research, or formulas the reader needs to
understand to perform the experiment (or solve the problem).]
Methods and Observations
Materials
 Lab notebook
Background:
The ability to taste PTC (a bitter substance to some while tasteless to others) and the ability of an
individual to roll their tongues in to a “U” shape when extended from the mouth are both dominant
traits. People who have these dominant alleles are called “tasters” and “rollers.” They are designated as
“T” and “R,” respectively. The inability to taste PTC or to roll the tongue is caused by being
homozygous in the recessive alleles, which are designated as “t” and “r,” respectively. Those who are
Moore, Timothy
homozygous with the recessive alleles are called “nontasters” and “nonrollers.”
Procedure:
I first drew a 1 x 1 Punnett square in my lab notebook, and filled in the square with the following cross:
a man that has a homozygous taster/roller and a woman that is a nonstaster/nonroller. Using this
information, I was able to determine that the genotype and phenotype of the children. [Include the
genotype and phenotype that you determined.]
Next I made a 4 x 4 Punnett square, this time crossing a heterozygous taster/roller with another of the
same genotype. I then determined the percentage chance of producing roller/taster, roller/nontaster,
nonroller/taster, and nonroller/nontaster.
DATA:
[Include your Punnett squares and percentage data here.]
Conclusion
My observations [You must explain, analyze, and interpret your results, being especially careful
to explain any errors or problems.]
References
Dr. Jay L Wile and Marilyn F. Durnell
Apologia Exploring Creation with Biology, 2nd edition, copyright 2005 Apologia Educational
Ministries, Inc