Karyotypes can be studied to determine an organism’s chromosomal makeup and to detect genetic defects. Down syndrome is a genetic disorder that is also called trisomy 21. What would trisomy 21 look like in a karyotype?
a.missing chromosome 21
b.extra chromosome 21
c.missing sex chromosome
d.extra sex chromosome

Question

Karyotypes can be studied to determine an organism’s chromosomal makeup and to detect genetic defects. Down syndrome is a genetic disorder that is also called trisomy 21. What would trisomy 21 look like in a karyotype?
a.missing chromosome 21
b.extra chromosome 21
c.missing sex chromosome
d.extra sex chromosome

bioepic · Answer

A clue here would be "tri-", which indicates three.
There would be an extra chromosome 21, which is choice B.