Question

Which of the following statements about bacterial mRNA transcript is TRUE?

1) Unlike eukaryotes, bacterial mRNA transcripts do not typically contain untranslated regions.
2) The Shine-Dalgarno box associates with an RNA component in the small subunit of ribosomes.
3) Transcription and translation take place sequentially in bacterial cells.
4) Most of bacterial genes contain a large number of introns and small number of exons.
5) The 5′ end and 3′ end of mRNA transcripts are modified in bacteria.

Answer 1

The true statement about bacterial mRNA is that the Shine-Dalgarno sequence interacts with the small subunit of the ribosome. Bacterial mRNA transcripts are generally not processed like eukaryotic mRNAs and lack introns.

Step-by-step explanation:

The correct statement about bacterial mRNA transcript is that the Shine-Dalgarno box associates with an RNA component in the small subunit of ribosomes. In bacterial cells, transcription and translation occur concurrently in the cytoplasm because there is no nucleus to separate the processes. This allows for simultaneous transcription, translation, and even mRNA degradation. Bacterial mRNA does typically contain untranslated regions, but they are not as elaborate as those in eukaryotes. Furthermore, bacterial mRNA transcripts are typically not processed as eukaryotic mRNAs are; they do not receive a 5′ cap or a poly-A tail, and most bacterial genes are organized into operons and encode polycistronic mRNA, meaning they lack introns and have continuous coding sequences.

Answer 2

The TRUE statement about bacterial mRNA transcript is: 2) The Shine-Dalgarno box associates with an RNA component in the small subunit of ribosomes.

So, the true statement is option 2.

Step-by-step explanation:

1.Unlike eukaryotes, bacterial mRNA transcripts do typically contain untranslated regions. These regions include the 5' untranslated region (5' UTR) and the 3' untranslated region (3' UTR), which are important for various regulatory functions.

2.The Shine-Dalgarno box, a conserved sequence in bacterial mRNA, is involved in ribosome binding. It associates with a complementary sequence on the ribosomal RNA in the small subunit of ribosomes, facilitating the initiation of translation in bacteria.

3.In bacteria, transcription and translation are coupled processes that can occur simultaneously, unlike eukaryotes where these processes are spatially and temporally separated.

4.Bacterial genes generally lack introns and exons. Unlike eukaryotic genes, most bacterial genes are contiguous sequences that encode proteins without the interruption of introns.

5.Unlike in eukaryotes where mRNA undergoes various modifications, such as capping and polyadenylation, the 5′ end and 3′ end of mRNA transcripts are not typically modified in bacteria.