Question

If a centromere probe is used in FISH analysis how many spots will light up in the cells of an individual with trisomy 21?

Answer 1

There will be three spots that will light up.

Step-by-step explanation:

There is a research paper published which demonstrated the trisomy of 21 chromosome. They found out that there are total three spots that light up in Trisomy 21 (down's syndrome's fetus). I have attached picture from research paper and provided the reference below.

Reference

(Davies, A. F., Barber, L., Murer-Orlando, M., Bobrow, M., & Adinolfi, M. (1994). FISH detection of trisomy 21 in interphase by the simultaneous use of two differentially labelled cosmid contigs. Journal of medical genetics, 31(9), 679-685)