Module 6 Mendelian Genetics

Lesson 4 Lab: Mouse Genetics (Two Traits)

Mendel wanted to know if the separation of alleles on one gene had any effect on the separation of alleles on another. To test this, he looked at plants that were pure breeding for two traits at once. He crossed plants that were true breeding for two traits with plants that were true breeding for the opposite forms of the same traits. In conducting and analyzing those crosses, Mendel was able to discover predictable patterns and ratios in the phenotypes of the F1 and F2 offspring.

In this simulation, you will explore mouse coat colour and eye colour as two separate genetic traits. You will conduct various breeding cycles until you understand how each trait separates in the F1 and F2 offspring. You will also determine if the movement of alleles for one trait has any effect on the movement of alleles for the other trait.

Problem (Purpose)

Manipulate the P1 breeding pair and observe the resulting offspring to determine which allele is dominant for each trait, and to see if one trait has an effect on the other.

Materials

For this simulation you will require access to the Internet and a word processing program to record your results.

Procedure

Open the Gizmo on Mouse Genetics.

Locate the “Exploration Guide” and open this document. In this investigation you will follow the instructions listed in the exploration guide for the parts titled

• Patterns of inheritance
• Independent Assortment

As you read and follow the instructions, make sure you are able to answer the questions listed for yourself. Some of them will be repeated later in this lab for you to submit to your instructor.

Observations

Patterns of Inheritance

Follow all of the instructions under this heading. Stop after you have completed Step 4.