Module 6 Mendelian Genetics

3.6.3 page 3

Lesson 3 Lab: Chicken Genetics

Not all genes have one dominant and one recessive allele. Sometimes the presence of any allele leads to some kind of change in phenotype. With flower phenotype, if you have one of each allele, you have a blend and the resulting phenotype is pink. In this simulation you will explore chicken colour. You will conduct various breeding cycles until you determine the mode of inheritance, and until you can answer all of the questions based on co-dominance.

Problem (Purpose)

Manipulate the P1 breeding pair and observe the resulting offspring to determine the mode of inheritance for colour in chickens.

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 Chicken Genetics. (Put your username/password into the top login box.) In this investigation you will follow the instructions listed in the exploration guide for the part titled “Inheritance of a Co-dominant Trait.”

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 for assessment.

Observations

The top two spots in the hen house are the P1, or parental generation. Whichever two chickens you place here will breed to create the other five spots you see in the hen house. Your first breeding pair should consist of one red and one white chicken. What kind of offspring result? Does it matter how many times you click “breed”? The next set of parents should be two heterozygous birds (mixed colour for phenotype). What kind of offspring may result from this cross? As asked in the Exploration guide, run this cross until you have at least 100 offspring.