Which of the following statements about histone and gene expression is CORRECT?
A)In a general sense, highly condensed DNA bound with histone proteins represses gene expression.
B)Acetylation involves the addition of acetyl groups to histone proteins, and it usually results in repression of transcription.
C)Addition of methyl groups to the tails of histone proteins always results in activation of transcription.
D)Histone code is referring to the modification that takes place on the globular domain of the octomeric histone core.
E)All statements above are correct.

Question

Quizplus · Accepted Answer

Highly condensed DNA bound with histone proteins, otherwise known as heterochromatin, is associated with gene silencing or repression. The tight packaging of chromatin in heterochromatin makes it difficult for transcription factors and RNA polymerase to access the DNA, hence hindering transcription. Acetylation of histone proteins, on the other hand, promotes transcription by relaxing the chromatin structure and enabling transcription factors and RNA polymerase to bind to the DNA. Methylation of histone tails can either activate or repress gene expression, depending on the location and pattern of methylation. The histone code refers to the various modifications that take place on the N-terminal tails of histone proteins.

Which of the Following Statements About Histone and Gene Expression