DRAGON GENETICS LAB
BACKGROUND
Dragons are an extremely endangered species and researchers are interested in
documenting the genetics of the species and starting a captive breeding program in order to
increase the dragon population. Each student will become a surrogate dragon parent. Dragons
have five pairs of homologous chromosomes (2n = 10), including a single pair of sex
chromosomes and four pairs of autosomes. Students will analyze the chromosomes of their
dragon and determine its genotype and resulting phenotype. This information will be recorded on
the following pages to aid in future dragon research and captive breeding programs.
Next, students will seek out another student with a dragon that is of a different gender
then their own and allow their dragons to mate. Dragons, like all other sexually reproducing
organisms, produce gametes by meiosis. During meiosis each dragon will produce haploid
gametes containing only one allele from each gene. Meiosis will occur according to the same
principles of segregation and independent assortment that are typically observed in meiosis. The
alleles for each gene on each inherited chromosome will be documented. This information will
then be used to determine the genotype of the baby dragon and predict its phenotype.
PROCEDURE
1. Each student must pick up five pairs popsicle stick chromosomes – two of each color of
autosome, and two sex chromosomes.
2. For each pair of colored autosomes, and then for the pair of sex chromosomes, each parent
will randomly drop his or her chromosomes on the table. The side of the stick that is facing
up represents the combinations of alleles in your pet dragons genotype. Arrange the
chromosomes in front of you in homologous pairs (matching colors). Be sure to keep them
with the same side facing up for the rest of this lab or you will become extremely confused.
3. Look at the homologous pair of sex chromosomes and determine if your dragon is a male or
female. Record this information at the bottom of the data sheet.
4. Record the pairs of alleles from each pair of homologous chromosomes in the data chart
under parental genotype (If your dragon is female use the “mom” box. If your dragon is male
use the “dad” box.
5. The decoding table indicates the phenotypic effect of each gene. The trait produced by each
pair of parental alleles should be recorded in the data chart under parental phenotype.
Remember not all traits follow normal Mendelian inheritance patterns of strictly dominant or
recessive. Check for alternate inheritance patterns such as codominance, incomplete
dominance, pleiotropy, or polygenic inheritance at the bottom of the decoding table.
6. Before they can mate dragons must produce gametes through the process of meiosis. To
simulate the production of gametes by meiosis we will flip a coin. Heads, the gamete
contains the chromosome on the left in each homologous pair of chromosomes. Tails, the
gamete contains the chromosome on the right in each homologous pair of chromosomes.
You will need to flip a coin once for each pair of homologous chromosomes. Record the
alleles from each of the inherited chromosomes in the appropriate “alleles found in” column
of the data table. (If your dragon is male it produces sperm, if it is female it produces eggs)
7. Now that you know the genetic make-up of your dragon you are ready to have it mate with
another dragon. Find another dragon surrogate parent with a dragon whose genetic make-up
has been completed and is known to be of a different gender. Record the name of your
dragon mates surrogate parent at the bottom of the data sheet.
