Question 9

(Multiple Choice)

X-inactivation is caused by the accumulation of:


A)proteins produced by the Xist gene; these proteins induce methylation, histone modification, and other changes associated with preventing transcription.
B)coding RNA produced by the Xist gene; this RNA, in addition to coding for Xist proteins, binds to and coats the X chromosome undergoing inactivation and physically prevents it from being transcribed.
C)noncoding RNA produced by the Xist gene, which coats the X chromosome and covalenty crosslinks the DNA strands preventing them from being unwound, "unzipped," and transcribed.
D)noncoding RNA produced by the Xist gene, which coats the X chromosome and induces DNA methylation, histone modification, and other changes associated with preventing transcription.
E)None of the answer choices accurately describes the process of X-inactivation.

Answer