#Question id: 4088
#Unit 3. Fundamental Processes
The 28S, 18S, and 5.8S rRNAs are
a. transcribed by RNA polymerase II.
b. encoded by a single transcription unit.
c. arranged in tandem arrays.
d. processed in the cytoplasm.
#Question id: 4089
#Unit 3. Fundamental Processes
An investigator incubates an unprocessed RNA molecule containing an intron in an extract absent of any protein. Correct splicing of the RNA is observed, but only when guanosine is present. What can the investigator conclude about the RNA molecule?
a. It contains a ribozyme.
b. Self-splicing has occurred.
c. It contains a group II intron.
d. It contains a group I intron.
#Question id: 4090
#Unit 3. Fundamental Processes
Tryptophan synthesis can be controlled by a process called attenuation in which the levels of tryptophan in the cell control translation by
#Question id: 4091
#Unit 3. Fundamental Processes
To avoid being degraded by nuclear exonucleases, nascent transcripts, pre-mRNA-processing intermediates, and mature mRNAs in the nucleus must have their ends protected. Which of the following mechanism are present in the cell to protect mRNA from degradation?
I. The 5′ cap is protected because it is bound by a heterodimeric nuclear cap-binding complex (CBC), which protects it from 5′ exonucleases and also functions in export of the mRNA to the cytoplasm.
II. 5’-5’ phosphodiester bond in the cap of mRNA plays crucial role in protection
III. The 3′ end of a nascent transcript lies within the RNA polymerase and is thus inaccessible to exonucleases
#Question id: 4092
#Unit 3. Fundamental Processes
An experimental setup provided the assay for identifying factors that facilitate transcription in the presence of chromatin. A factor called FACT (facilitates chromatin transcription) functions as
#Question id: 4093
#Unit 3. Fundamental Processes
Which of the following processes is NOT an example of allosteric regulation?