Reebop Reproduction
The species M. Reebopus is prolific and requires minimal care, making it an excellent laboratory
animal. Your job is to simulate reproduction between a male and female Reebop by using gametes
determined by chance, just as gamete production occurs in nature. In this lab, you will sort
chromosomes simulating meiosis and demonstrate Mendel’s Law of Segregation and Law of
Independent Assortment.
Materials
Day 1:
Baggie containing chromosomes from Mom and Dad Reebop
Day 2:
Marshmallows, regular white
Marshmallows, small, assorted colors as determined by your chromosome selection
Toothpicks
Thumbtacks
Pipe cleaners
Straight pins
Red or black licorice
Procedure:
1. Meet Mom and Dad Reebop. They are on the front desk. You will receive a baggie containing
their chromosomes. Mom’s chromosomes are red and Dad’s chromosomes are green. NOTE:
real-life chromosomes are not red or green depending on parent gender. Also, both Mom and
Dad would produce another copy of each chromosome, 4 in all.
2. Lay out the chromosomes for either Mom or Dad while your partner lays out the
chromosomes for the other parent. Pair the chromosomes, making sure the letters are facing
up. The chromosomes are now sister chromatids in homologous pairs. In meiosis, each
homologous pair would replicate. The identical pairs would form a tetrad. Sketch a tetrad
for any one of the chromosomes for either Mom or Dad Reebop.
3. Record the genotype and phenotype for Mom and then for Dad in a table.
4. Each egg produced by Mom can receive one of her chromosomes. Each sperm produced by
Dad can receive one of his chromosomes. Choose all of the chromosomes from Mom and
from Dad for gender (all of the X and Y chromosomes.) Place them face down on the table
and mix them up.
5. Choose one red chromosome (Mom) and one green chromosome( from Dad.) Record the
genotype and phenotype of your new baby in the table on your data sheet.
6. Now, choose all 4 of the chromosomes for antennae (they will have A or a.) Place them face
down, mix them, and select one red (from Mom) and one green (from Dad). Do not turn the
chromosomes over. Set the unused pair chromosomes aside. Continue with each pair of
chromosomes until you have selected 7 traits and the gender of your baby Reebop.
7. Turn over the chromosomes you selected. Record the genotype and phenotype of your baby
in the table on your datasheet.
8. Lay out all the chromosomes you used and didn’t use in homologous pairs once again. After
you have determined that you have all the chromosomes, place them back all into the baggie,
seal it, and return it.