# Chromosomes and Genes - A Simulation

Objective: In this simulation you will examine how alleles are inherited in an organism. The alleles govern the traits for blood type, coat color, and bob tails in cats. In this simulation, the alleles for bobtails and ear shape are located on the same chromosome. The alleles for coat color are located on the sex chromosomes.

In your bag you have 6 chromosomes, represented by pipe cleaners. The white represent autosomes, and the red and blue represent sex chromosomes. Blue for Y, Red for X

You also have beads to represent the alleles for the following traits. You only have 4 white chromosomes for the three traits: blood type, tails, and ears because the tails and ears alleles are located on the same chromosome.

 Coat Color - sex linked, codominant BB = black Bb = black & white, spotted bb = white Beads used: Black (B) & white (b) Blood Type - multiple allele trait AA or AO = type A BB or BO = type B AB = type AB OO = type O Beads used: Red (A), Blue (B), Clear (O) Bob Tails - Single Allele Trait TT = normal tail Tt = normal tai tt = bobtail Beads used: Orange (T) & Yellow (t) Ear Shape: -Single Allele trait RR = rounded Rr = rounded rr = pointed Beads used: Purple (R) & Pink (r) - alleles located on the same chromosome as bobtail alleles

## Parent Genotypes

 Male The dominant alleles TR are on different chromosomes Female ** The dominant alleles TR are on the same chromosome

Using the pipe cleaners and beads, one partner constructs the male genotype, and the other constructs the female genotype.

Instructor Initials
If you got this step wrong, your simulation data will be wrong.

With the parents' genotypes given. Predict the phenotypic ratios for each trait, using a punnet square method. Show your work and calculations below

 Coat Color Blood Type Tails & Ears

#### Run the Simulation

As parents, you will contribute HALF of your genes to the offspring. For each chromosome set, place behind your back and have your partner choose at random which chromosome will be donated to the offspring. One chromosome of each type must be donated from each parent, so that the offspring has a complete set. The offspring will probably not be like either of the parents.

You will repeat this process 12 times to complete the data table below. For each offspring, list the phenotype for each trait.

 Sex Coat Color Blood Type Tail Ears Offspring 1 Offspring 2 Offspring 3 Offspring 4 Offspring 5 Offspring 6 Offspring 7 Offspring 8 Offspring 9 Offspring 10 Offspring 11 Offspring 12

### Analysis

1. Compare your predicted values with your actual values (from the simulation).

 Black Females Spotted Females Black Males White Males Type AB Blood Type A Blood Type B Blood Normal tail, round ears Normal Tail, pointed ears Bobtail, round ears Bobtail, pointed ears Actual (from simulation) Predicted (from Punnett)

Analysis

1. How do the predicted values compare to the actual values from the simulation?

2. What do the pipercleaners represent?

3. What do the beads represent?