Question

The amount of histone mRNA in the cell is reduced after DNA synthesis is completed by:

a. increasing the level of transcription of the histone genes.
b. by decreasing the rate of translation of the histone mRNA.
c. by alternative splicing of the histone mRNA.
d. by increasing the rate of degradation of the histone mRNA.
e. all of the above

Answer 1

Histone mRNA levels are decreased after DNA synthesis by increasing the rate of its degradation, adjusting to the reduced need for new histones once DNA replication is done.

Step-by-step explanation:

The amount of histone mRNA in a cell is reduced after DNA synthesis is completed primarily by increasing the rate of degradation of the histone mRNA. This decrease occurs because histones are needed during DNA replication to package the newly synthesized DNA into nucleosomes. Once DNA synthesis is finished, the demand for histones decreases, and so does the stability of histone mRNA, resulting in its degradation. The regulation of histone mRNA levels does not typically involve changes in the rate of transcription, translation alterations, nor alternative splicing for this purpose.