1. A. A mutation in E. coli is found that fails to induce the arabinose operon. Upon further investigation, it is found that this mutant also is unable to induce the lac operon. Which of the following single mutations could explain this phenotype (you may choose one or more answers a) Mutation in the promoter of the ara operon b) Mutation in the promoter of the lac operon c) Mutation in the operator of the lac operon d) Mutation in the AraC protein for the ara operon e) Mutation in the repressor of the lac operon f) Mutation in the Y gene for Lac permease g) Mutation in the gene for adenylate cyclase h) Mutation in the gene for CAP (or CRP) protein i) Mutation in the gene for rho factor j) None of the above

Q: 1) The logic of the Lac operon was deciphered by using bacterial lac-operon mutants. Crucial to the…

A: Lac operon is a genetic unit in bacteria that helps in the metabolism of lactose in E.coli and lac…

Q: Assuming that the level of glucose is low, a mutation in the repressor associated with the lac…

A: The lac operon stands for lactose operon. These are a set of genes that are found in E.coli and…

Q: closely linked open reading frames (ORFs) have been identified on the E. coli chromosome and they…

A: E.coli being a prokaryote consists of an operon which is the cluster of genes that helps in the…

Q: Name and describe two types of constitutive mutants of the lactose operon.

A: Operon can be defined as an operating unit, which is nothing but gene clusters that are located…

Q: Operons are a common feature of bacterial genomes. Which of the following statements about the lac…

A: Lac operon has three important genes that helps the bacteria to take up the lactose sugar when…

Q: Which of the following statements about the la a) The repressor only leaves the operator v product…

A: The lac operon is a cluster of genes in bacteria responsible for lactose metabolism. It consists of…

Q: If lactose isn't present in the environment of an E. coli, what is the state of the lac operon? O a.…

A: The lactose operon (also known as the lac operon) is a group of genes present in E. coli and other…

Q: Explain how the lac operon normally functions

A: Lac operon is a group of genes with a single promotor (gets transcribed as single mRNA). These genes…

Q: The trp operon in E. coli is a negative repressible operon. This implies that...   a. The trp…

A: The correct answer is:c. The trp operon makes use of a repressor and can be turned "on" (i.e., is…

Q: coli WT (wild type, everything is functional) and II) E. coli whose lacl ger ed, when each of the 2…

A: the lacI gene is a regulatory gene for lac operon It produces a protein that blocks RNA polymerase…

Q: Strain X-23 has a mutation in the lacI gene resulting in a lacI protein that cannot bind DNA.…

A: The operon model is applicable in bacterial gene regulation and some lower eukaryotes gene…

Q: Which of the following is false when the genes of the Lac operon are being tran- scribed in high…

A: Lac operon is a set of genes used by E.coli to metabolize lactose when glucose is not available for…

Q: Consider the lac operon of E. coli. Specifically, explain the following: a. Describe the overall…

A: The lac operon is a collection of genes located in the chromosome of Escherichia coli, and it…

Q: Compare and contrast the functional mechanism of the Inducible - Lac operon  with the Repressible -…

A: Gene expression is a process in which the genetic instructions of genes are utilized to manage…

Q: The attenuation mechanism that helps block expression of the tryptophan operon requires all of the…

A: In transcriptional attenuation, the expression of genes are negatively regulated by controlling the…

Q: Which protein(s) would be bound to the DNA of the lac operon in the presence of both lactose and…

A: INTRODUCTION Lac operon This is group of genes having a single promoter. It contain protein that…

Q: When lactose is first introduced into the medium, the lac operon is not induced and thus permease…

A: The lac operon in E.coli consists of 3 genes (lac Z, lac Y, lac A). The lac Z encodes beta…

Q: You can determine the regulation of an unknown operon based on descriptions like those in the table…

A: Introduction  The expression of genes is highly regulated in both prokaryotes as well as in…

Q: A mutation that inactivates transcription and translation from the regulatory gene of an inducible…

A: An operon is a functional unit of genomic DNA that comprises a collection of genes that are all…

Q: Match each of the following mechanisms with how it can change the levels of gene products--whether…

A: Operons are DNA segments that include groups of associated genes. They consist of a promoter region,…

Q: 1) The UR operon which is composed of sequences A, B, C, and D (which may or may not be genes of…

A: An operon may be considered as a group of certain genes which function together so as to regulate…

Q: What statement is NOT true regarding transcription attenuation of amino acid biosynthetic operons?…

A: Amino acid biosynthesis is an anabolic process in which a molecule is synthesized as an end product.…

Q: Bacteria with a lac phenotype are unable to use lactose because of some defect in expressing the…

A: Answers - 1) False 2) True 3) True  There are 3 structural genes in lac operon - lac Z, lac Y and…

Q: The symbols A, B, C, D, E represent all the components of the lac operon, excluding LacA. The…

A: The lac operon regulates gene expression in lactose metabolism in E. coli. It is composed of a…

Q: Which of the following environmental conditions would be MOST likely to result in transcription of…

A: The transcription of the lac Oberon in an E.colicell is high levels of lactose and high levels of…

Q: Read the following statements about operons, and mark the FALSE one. O a. Prokaryotes use operons…

A: Operons are a group of genes that are regulated together in prokaryotic cells. They consist of…

Q: Which of the following statements about operons are true? (Check all that apply) Operons are common…

A: Ans: An operon is a cluster of the genes found in bacteria and viruses, these genes transcribed to…

Q: The operator of the lac operon is upstream of the gene that codes for enzymes. What does upstream…

A: Lac operon: The lac operon is a genetic regulatory system found in bacteria that controls the…

Q: Strain P77 has a mutation in the lacO that prevents it from being bound by the lacI protein.…

A: Gene regulation at the level of transcription in bacteria is achieved by the operon model. Operon…

Q: Suppose you have an E. coli in which the gene that codes for the lac repressor protein has been…

A: Lac operon is an inducible type of operon that involves the breakdown of lactose in E.coli.  The lac…

Q: 7. If a researcher moves the promoter for the lac operon to the region between the beta…

A: Lac operon is a bacterial gene and it works through a repression mechanism. lac I produces repressor…

Gene Interactions

When the expression of a single trait is influenced by two or more different non-allelic genes, it is termed as genetic interaction. According to Mendel's law of inheritance, each gene functions in its own way and does not depend on the function of another gene, i.e., a single gene controls each of seven characteristics considered, but the complex contribution of many different genes determine many traits of an organism.

Gene Expression

Gene expression is a process by which the instructions present in deoxyribonucleic acid (DNA) are converted into useful molecules such as proteins, and functional messenger ribonucleic (mRNA) molecules in the case of non-protein-coding genes.