Download Pipe Cleaner Babies - The Northwest School

Pipe Cleaner Babies
Objective: In this activity you will represent one parent, and your lab partner will take
the role of the other parent. You will use chromosome and gene models to create four
offspring and determine their genotypes and phenotypes. Then, mathematically, you
will calculate the probability of have offspring with different traits.
Activity Description: You and your partner will each receive a bag with pipe
cleaners and beads. The pipe cleaners represent chromosomes, and the beads are
genes located on the chromosomes. In humans, there are 23 pairs of chromosomes.
For this activity, we will use just three pairs.
Observe the chromosomes in your bag. The pink and blue chromosomes represent sex
chromosomes. If you have 2 pink chromosomes (XX), you represent the female. If you
have one pink and one blue chromosome (XY), you represent the male. The other four
chromosomes are called autosomes - they carry genetic information that does not
necessarily relate to genetic gender.
_______________________ 1. What do the pipe cleaners represent?
_______________________ 2. What do the beads represent?
_______________________ 3. Which parent is represented by the pink chromosomes?
_______________________ 4. Which parent is represented by the pink and blue ones?
_______________________ 5. What is a genotype?
_______________________ 6. What is a phenotype?
The Parents’ Traits: Remove the chromosomes from your bag, but make sure you
do NOT mix up your chromosomes with those of your partner. Arrange the
chromosomes in order of size; you should have two long, two short, and the pink/blue
chromosomes.
1. Eye Color Trait (found on long pipe cleaners)
• _____ bead (B) = ________ eyes = Dominant
• _____ bead (b) = Blue eyes = Recessive
Genotype
Phenotype
BB
Brown eyes
Bb
Brown eyes
bb
Blue eyes
__________________________ 7. What eye color does the “mom” have?
__________________________ 8. What is her genotype regarding this trati?
__________________________ 9. What eye color does the “dad” have?
__________________________10. What is his genotype regarding this trait?
2. Hair Color Trait (found on next longest pipe cleaners)
• _____ bead (D) = Dark hair = Dominant
• _____ bead (d) = Blonde hair = Recessive
Genotype
Phenotype
DD
Dark hair
Dd
Dark hair
dd
Blonde hair
__________________________ 11. What hair color does the “mom”
have?__________________________ 12. What is her genotype regarding this
trait?__________________________ 13. What hair color does the “dad”
have?__________________________ 14. What is his genotype regarding this trait?
3. Ear Lobes Trait (found on shortest pipe cleaners)
• ______ bead (G) = Free earlobes = Dominant
• ______ bead (g) = Attached earlobes = recessive
You should be able to fill this chart in by now
Genotype
Phenotype
___________________________ 15. What type of earlobes does the “mom” have?
___________________________ 16. What is her genotype regarding this trait?
___________________________ 17. What type of earlobes does the “dad” have?
___________________________ 18. What is his genotype regarding this trait?
4. Hemophilia Trait (found on pink pipe cleaners): Hemophilia is a recessive disorder
that causes the blood to take a long time to clot after injury. The X chromosome carries
the recessive gene that causes hemophilia. Since a male only has one X chromosome,
then it is far easier for him to inherit this disorder than his sister. Girls rarely have this
disorder since they would have to inherit two recessive hemophilia alleles. A female
with one recessive gene is called a carrier. If she passes this gene along to her son, he
will inherit the disorder.
• ______ bead (H) = Normal clotting blood = Dominant
• ______ bead (h) = Hemophilia = Recessive
Genotype FEMALE XX
HH
Phenotype
Normal clotting
Genotype FEMALE XX
Phenotype
Hh
Normal clotting (carrier)
hh
Hemophilia
Genotype MALE XY
Phenotype
H
Normal clotting
h
Hemophilia
___________________________ 19. What is the “mom’s” genotype?
___________________________ 20. Is she a carrier?
___________________________ 21. What is the “dad’s” genotype?
___________________________ 22. Why doesn’t he get TWO genes for this trait?
___________________________
Time to Start Your Family:
• First the “dad” places one set of chromosomes (e.g. the set for eye color) behind
“his” back (one chromosome in each hand).
• The “mom” picks a hand (chromosome).
• Then the “mom” places the same set of chromosomes (e.g. the set for eye color)
behind “her” back (one chromosome in each hand)
• The “dad” picks a hand (chromosome)
• Repeat this process for the three other traits for this child
• Repeat the whole process to create a total of four offspring.
• Record your trait results in the data table below.
Family
Child #1
Sex
Hemophilia
M/F
Yes / No
Eye Color
Hair Color
Earlobes
Family
Sex
Hemophilia
Child #2
M/F
Yes / No
Child #3
M/F
Yes / No
Child #4
M/F
Yes / No
Eye Color
Hair Color
Earlobes