I believe the poetic device is parallelism
Parallelism is a literary device in which parts of the sentence are grammatically the same, or similar in construction. It may be a word, a phrase, or an entire sentence repeated. This technique adds symmetry, effectiveness and balance to the written piece. It is important as it allows the writer to achieve a sense of rhythm and order.
Answer:
RNA
Explanation:
Transcription is the first process of protein synthesis and it involves copying the information encoded in the genetic material (DNA) to a RNA molecule. It involves making a complementary strand of mRNA from a DNA template.
The process of transcription commences when an enzyme called RNA polymerase binds to the promoter region of a gene on the DNA, signalling the unwinding of its double-stranded structure. The RNA polymerase then adds nucleotides to the growing RNA molecule, complementary to the ones it reads on the DNA. The RNA synthesized during transcription is called messenger RNA (mRNA).
The mRNA is then used as a template for amino acids synthesis during translation.
If a lot of tryptophan is present, the operon will be repressed.
Under intermediate amounts of tryptophan, the change to stop codons would cause the ribosome to stall and therefore would mimic as if there were no tryptophan present.
If no tryptophan present, the operon would be maximally expressed.
a - True. The ribosome would always be stalled in the leader sequence - so this wouldn't matter. However, the operon would still be transcribed because the repressor would be active (remember Trp operon is controlled both by attenuation and repression). True as long as there's not much tryptophan to activate the repressor!
b- True - With no tryptophan the repressor isn't engaged and the ribosome is stalled in the leader sequence.
c- Matters about how much tryptophan is available. So True if there's lots of tryptophan available.
d- I would choose this one as all of the above could be true depending on the levels of tryptophan.
I believe the correct one is the 2nd option .