1. Familial Down syndrome is due to a Robertsonian translocation between chromosomes 14 and 21.
a. (3 points) What is a "Robertsonian translocation"?
b. (1 point) Does an individual who is a carrier for the Robertsonian translocation between
chromosomes 14 and 21 exhibit Down Syndrome? (Yes/No)
2. (6 points) A parent who is a carrier for the Robertsonian translocation between chromosomes 14 and 21
has children with a parent who is chromosomally normal with two copies of chromosome 14 and two
copies of chromosome 21.
a. What are the possible gametes that the parent with the Robertsonian translocation can produce?
Only list chromosomes 14, 21, and the translocation 14-21. Do not list other chromosomes.
b. For each of these gametes, what is the result for the fertilized zygote? Possible answers include
Normal, Translocation carrier, Trisomy 21, Monosomy 21, Trisomy 14, and Monosomy 14
Gamete - chromosomes 14, 21, and/or 14-21?
Fertilized zygote