Concept explainers
a.
To determine:
The number of genes and operons depicted in the figure, the average gene density, and the representativeness of the value to the most bacterial genomes.
Introduction:
The mentioned figure shows the RNA-Seq results from the RNA-Seq experiment. In the analysis part, the computer lines up each of cDNA sequence read with the genome sequence of the bacterium.
b.
To determine:
Whether the given data proves that t2110 is nonfunctional and the process by which scientists were able to assign a direction to the transcription when no transcript of the gene was found.
Introduction:
In the performed experiment, it was found that no transcripts for the gene t2110 were detected.
c.
To determine:
The evidence that suggests the existence of an attenuation or riboswitch mechanism, causing premature transcriptional termination of an operon and the observation of any of the operon that might be controlled by such a mechanism.
Introduction:
The process of attenuation is considered as the method of control in some bacterial operons, and it causes premature termination of transcription.
d.
To determine:
The depiction of the given figure if the antisense mechanism was involved in controlling the gene or operon.
Introduction:
The mentioned figure does not provide any evidence that any of the genes or operons are regulated by an antisense transcript.
e.
To determine:
The possibility of the transcription of the galM gene from the different promoter.
Introduction:
The given figure depicts galM gene to be a part of the operon containing galETK. There is even a possibility that galM is transcribed from a separate promoter.
f.
To determine:
Whether the data shown in the figure reveal the presence of a regulatory mechanism in relation to an sRNA occluding the ribosome binding site.
Introduction:
The ribosome binding site is present in upstream to the start codon. It is a sequence of nucleotides which play an important role in recruiting the ribosome at the initiation of the translation process.
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Genetics: From Genes to Genomes
- Listed in parts a through g are some mutations that were found in the 5′ UTR of the trp operon of E. coli. What will the most likely effect of each of these mutations be on the transcription of the trp structural genes? a. A mutation that prevents the binding of the ribosome to the 5′ end of the mRNA 5′ UTR b. A mutation that changes the Trp codons in region 1 of the mRNA 5′ UTR into codons for alanine c. A mutation that creates a stop codon early in region 1 of the mRNA 5′ UTR d. Deletions in region 2 of the mRNA 5′ UTR e. Deletions in region 3 of the mRNA 5′ UTR f. Deletions in region 4 of the mRNA 5′ UTR g. Deletion of the string of adenine nucleotides that follows region 4 in the 5′ UTRarrow_forwardIf glucose is not available, but lactose is available from the environment, what is the status of transcription of the lac operon genes? Explain your answer from both an evolutionary perspective and in terms of negative and positive regulation of the operon?arrow_forwardYou then make a screen to identify potential mutants (shown as * in the diagram) that are able to constitutively activate Up Late operon in the absence of Red Bull and those that are not able to facilitate E. Coli growth even when fed Red Bull. You find that each class of mutations localize separately to two separate regions. For those mutations that prevent growth even when fed Red Bull are all clustered upstream of the core promoter around -50 bp. For those mutations that are able to constitutively activate the operon in the absence of Red Bull are all located between the coding region of sleep and wings. Further analysis of each DNA sequence shows that the sequence upstream of the promoter binds the protein wings and the region between the coding sequence of sleep and wings binds the protein sleep. When the DNA sequence of each is mutated, the ability to bind DNA is lost. Propose a final method of gene regulation of the Up Lateoperon using an updated drawn figure of the Up Late…arrow_forward
- If glucose levels in the cell are high and lactose is available from the environment, what is the status of transcription of the lac operon genes? Explain your answer from both an evolutionary perspective and in terms of negative and positive regulation of the operon?arrow_forward. Listed in parts a through g are some mutations that were found in the 5′ UTR of the trp operon of E. coli. What will the most likely effect of each of these mutations be on the transcription of the trp structural genes? Q. A mutation that changes the Trp codons in region 1 of the mRNA 5′ UTR into codons for alaninearrow_forwardA strain of bacteria possesses a temperature-sensitive mutation in the gene that encodes the rho subunit. At high temperatures, rho is not functional. When these bacteria are raised at elevated temperatures, which of the following effects would you expect to see? Explain your reasoning for accepting or rejecting each of these five options. a. Transcription does not take place. b. All RNA molecules are shorter than normal. c. All RNA molecules are longer than normal. d. Some RNA molecules are longer than normal. e. RNA is copied from both DNA strands.arrow_forward
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- What would happen to the regulation of the tryptophan operon in bacterial cells that express a mutant form of the tryptophan repressor that (1) cannot bind to DNA, (2) cannot bind tryptophan, or (3) binds to DNA even in the absence of tryptophan?arrow_forwardAnother class of suppressor mutations, not describedin the chapter, are mutations that suppress missensemutations.a. Why would bacterial strains carrying such missense suppressor mutations generally grow moreslowly than strains carrying nonsense suppressormutations?arrow_forwardIn addition to observing similarities to the lac operon, you also notice that this gene is regulated via attenuation, similar to the trp operon. Based on this similarity to this model operon, you could state that ___________. Group of answer choices If a terminator loop forms in the DNA, the expression of the structural genes is halted. The formation of the terminator hairpin followed by a series of Uracil (UUUUUUU) functions similar to Rho-Independent termination to result in the stopping of transcription. The transcription of a leader sequence affects the translation of the structural genes. Never mind – all of these statements are true! Attenuation will be the primary means of transcriptional regulation, with a repressor used as a back up option.arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning