Q: What are lac operon with suitable examples?
A: Bacteria such as E. coli usually live in animal intestines. Their food sources vary from hour to…
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: Explain how the lac operon is both positively and negativelycontrolled.
A: The lac operon of E. coli contains genes involved in lactose metabolism. It is expressed only when…
Q: Please help me iwht this question explain how the regulation of the Lac Operon incorporate both…
A: An operon includes a group of genes that are expressed under the same promoter.
Q: Compare and contrast the lac operon and trp operon of E. coli.
A: E.coli is a type of bacteria that is mostly found in the human intestine and gut of some animals. It…
Q: b) A haploid E. coli strain cultured in a lactose containing medium failed to transcribe the genes…
A: An operon is a gene expression and regulation unit of the bacteria that consists of the following…
Q: 1. Explain why catabolite repression is used in regulating the lac operon and describe how it…
A: Repression by glucose of beta-galactosidase synthesis is spontaneously reversible in all strains of…
Q: what is an attenuator? (in context of a prokaryotic operon )
A: Operons are prokaryotic arrangements of multiple genes under the control of a single promoter. The…
Q: Describe the structure of the Lac operon. How is it turned on? How is it turned off?
A: The gene products of the lac operon are very important for lactose metabolism. This is crucial for…
Q: Six strains of E. coli (mutants 1-6) that had one of the following mutations affecting the lac…
A: The mutations that would prevent the E.coli strain from utilizing lactose include deletion of lacY,…
Q: 4a. The diagram below represents (a) the lac operon in the OFF state and (b) lac operon in the ON…
A: Note - Since you have asked multiple questions, we will solve the first question for you. If you…
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: 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: Which of the following lac operon genotypes would allow for functional versions of all the…
A: lac operon: - Inducible system - Both positive and negative regulation. - Involved in lactose…
Q: 1 Given the following genotypes, explain how the mutation (identified by a () superscript will…
A: Operon is a unit consisting of one or more systems that function coordinately under the control of…
Q: 1. A. A mutation in E. coli is found that fails to induce the arabinose operon. Upon further…
A: A mutation is a change to the DNA sequence of a cell. This change can be due to rearrangements on…
Q: 4b. Briefly describe the changes in gene expression that happen in the lac operon when lactose is…
A: 4b- lac operon: - Inducible system. - Both positive and negative regulation. - Involved in lactose…
Q: Predict the growth/color pattern you'd expect for constitutive mutants for the lac operon. Table 1:…
A:
Q: operon
A: Answer: Operon: In genetics, an operon is a functioning unit of DNA containing a cluster of genes…
Q: Do you expect operons to occur extensively in Eukaryotes? Yes or no and explain.
A: Operons (clusters of co-regulated genes with related functions) are a well-known feature of…
Q: Which of the following mutations would result in the highest level of lac operon transcription in…
A:
Q: Explain how the following conditions will affect the regulation of the operon. Low cAMP levels; E.…
A: Operon is a sequence of DNA that consists of a set of genes which are involved in a particular…
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: 5a. The table below summarizes expression of B-galactosidase (lacZ) and permease (lacY) from the lac…
A: 5a) Lac operon is an inducible operon that is expressed in the presence of a substance termed…
Q: Describe a bacterial operon's structural advantage.
A: *NOTE: Kindly repost for other question. Dear Student as per the guidelines we are supposed to…
Q: In terms of the trp operon, differentiate between two normal bacterial cultures, one grown in a…
A: The trp operon, found in E. coli bacteria, is a group of genes that encode biosynthetic enzymes for…
Q: The lac operon consists of three structural genes, lacZ, lacY and lacA that are transcribed as a…
A:
Q: Which of the following arabinose operon regulatory sites is exclusively involved in the repression…
A: Answer - Option B - ara O2
Q: ou have isolated different mutants (reg1 and reg2) causing constitutive expression of the emu operon…
A: The operon's regulation can take place positively or negatively. If the negative operator is bound…
Q: Describe the main features of the lactose operon and inducibleoperons.
A: Inducible operons are those in which genes for certain enzymes can be turned on by the substrate of…
Q: A)Explain the mechanism by which the lac operon is sensitive to glucose levels (presence and absence…
A: “Since you have asked multiple question, we will solve the first question for you. If you want any…
Q: What is the phenotype of an E. coli strain with a mutation in the lac operator that allows the lac…
A: Operon is defined as a region of DNA where it is made up of clusters of related genes arranged under…
Q: The lac operon has 4 genes, I, Z, Y and A. For each scenario, tell me the result of the mutation,…
A: The lac operon is an operon or group of genes with a single promoter. The genes in the operon…
Q: Outline the operon theory using the lac operon as anexample
A: Operon consists of genes placed in sequential order. Lac operon has following genes- Regulator gene…
Q: If you make a large deletion in the lac operon to remove the operator region, will the structural…
A: Lac operpon Is an operon or a group of genes with a single promoter that encode genes for the…
Q: In prokaryotes, structural proteins in a single biochemical pathway are usually found as a(n)…
A: An organism's genome contains all of its genetic information. It gives the organism all of the…
Q: Bacterial DNA containing an operon encoding three enzymes is introduced into chromosomal DNA in…
A: Prokaryotes are the organisms that lack the cell nucleus and membrane-bound organelles. They have…
Q: Explain how elements of the lac operon are exploited to regulate recombinant protein production in…
A: Introduction Three structural genes, as well as a promoter, a terminator, a regulator, and an…
Q: Strain P77 has a mutation in the lacO that prevents it from being bound by the lacI protein.…
A: The operon model is applicable in bacterial gene regulation and also applicable in some lower…
Q: Explain how the following conditions will affect the regulation of the operon. (3 pts) Low cAMP…
A: Lac operon is a mechanism seen in the E coli that enables the proper metabolism in its body. The…
Q: Provide the SIGNIFICANT differences between the following: 1. Operon Systems Inducer/Lac…
A: An operon is a cluster of functional genes which are regulated by the common operator. Operons…
Q: Which of the following arabinose operon regulatory sites is exclusively involved in the repression…
A: Operon is a gene regulatory structure that contains clusters of genes and these clusters of genes…
Q: Strain ROFL4 has a premature stop mutation in the lacZ gene, resulting in a nonfunctional…
A: Answer: lac Z gene is the gene in lac operon where it is responsible for the formation of…
Q: 9. A single base substitution mutation in lacY gene of the Lac operon would render the entire lac…
A: Gene regulation at the level of transcription in bacteria is achieved by the operon model. Operon is…
Q: Please explain the structure of Lac operon in bacteria.
A: Gene regulation can be defined as any kind of alteration in the gene to give rise to a different…
Q: Select all of the cis-acting regulatory elements of the lac operon. Operator CAP+cAMP CAP+cAMP…
A: lac operon: - Inducible system - Both positive and negative regulation - Involved in lactose…
Q: To characterize the promoter of the gadA operon you made a series of deletion mutants removing…
A: Gad A gene expression is found in the bacteria. They have operon structure in which regulatory,…
Q: Highlight the main points of lac operon operation.
A: In prokaryotes, gene regulation is most prominent during the start of transcription. As a result,…
Q: humber of mutations affect the expression of the lac operon in E. coli. The genotypes of several E.…
A: Lac operon is a genetic unit that produces the enzymes necessary for the digestion of lactose. It is…
Q: Which statement does NOT explain why the lac operon would not be effectively regulated by an…
A: Lac operon is composed of a regulatory gene, promoter, operator, and structural genes. Lac operon is…
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.
2) Name and describe two types of constitutive mutants of the lactose operon.
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- 1. The following are genotypes of merozygotes of E. coli with various combinations of lac operon mutations. Determine the phenotype with respect to beta-galactosidase (z), permease (y), and trans-acetylase (a) of each combination as U = uninducible, I = inducible, and C = constitutive. Choose from the following answers. i- p+ o+ z+ y- a+ / i+ p+ oc z- y- a+ Answer choices UII UIC UUU ICC CUC IUC CCU 2. The following are genotypes of merozygotes of E. coli with various combinations of lac operon mutations. Determine the phenotype with respect to beta-galactosidase (z), permease (y), and trans-acetylase (a) of each combination as U = uninducible, I = inducible, and C = constitutive. Choose from the following answers. i- p+ o+ z- y+ a+ / iS p+ o+ z- y+ a+ Answer choices ICC CCU UII IUC UIC CUC UUU4. What are the effects of the following conditions on Lac operon of bacteria?A)Glucose is absent and lactose is presentB)Glucose is present and lactose is presentC) Glucose is present and lactose is absent2) Attenuation of the trp operon is controlled by the formation of stem-loop structures in the mRNA of the trpl region. The attenuation function can be disrupted by mutations that alter the sequence of the repeat DNA regions 1-4 and prevent formation of the RNA stem loops. Describe the most likely effects on attenuation of each of the following mutation under the conditions specified. a. Mutation in region 1 and low levels of tryptophan: b. Mutation in region 2 and low levels of tryptophan: Mutation in region 2 and moderate levels of tryptophan (low enough to release the repression but enough to allow the ribosome to NOT pause): с. d. Mutation in region 3 and low levels of tryptophan: е. Mutation in region 3 and moderate levels of tryptophan (low enough to release the repression but enough to allow the ribosome to NOT pause): f. Mutation in region 4 and low levels of tryptophan:
- 4). Mutants unable to synthesize an essential compound G were tested with related compounds D, E, and F. The results are summarized below, where + indicates growth, and 0 indicates no growth. Mutants 1 2 3 4 D 0 0 0 Compounds E 0 INAAL F 0 0 INAY a). What is the order of gene action in the biosynthetic pathway? G16. During early life many infants receive milk from the mother. One of the major components of milk is lactose. a) Consider the Lac operon in E. coli, and state what the expression of Lac Y would be in I) E. coli WT (wild type, everything is functional) and II) E. coli whose lacl gene has been delet- ed, when each of the 2 strains are growing in culture flasks that contain high glucose and high lactose. Hint: choose among 'high expression; low expression; no expression'for I) and II). 1) II) b) In the graph below, draw the expression of LacY over time in strains I and II, when each of the 2 strains are growing in culture flasks that contain high glucose and high lactose, as shown in part a). Hint: you can draw the curves on a piece of paper and copy and paste a picture of it, if it is difficult to draw the graph directly here. If you do so and you have a Mac, make sure to convert your exam into PDF by doing "Print > Save as PDF"; do not “Export as PDF". time (min) Make sure to label…35. The genes shown are from the lac operon system of E.coli. The symbols a, b and c represent the repressor (I) gene, the operator (O) region, and the structural gene (Z) for β-galactosidase, although not in that order. Furthermore, the symbols written in the genotypes are not necessarily the actual sequence in the lac operon.
- 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 B. Briefly explain the reasons for your choice(s)1. A)Explain the mechanism by which the lac operon is sensitive to glucose levels (presence and absence of glucose). B)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?2. The lac operon controls the inducible expression of genes involved in lactose utilization. Several naturally occurring mutations have been discovered that affect how the lac operon operates. Consider the following mutations: I-= a mutation in the repressor protein that cannot bind the operator Is = a mutation in the repressor protein that cannot be removed from the operator Oc= a mutation in the operator that cannot bind the repressor Detail the functionality of the lac operon with following genotypes and cellular conditions (Note if there is no superscript, there is no mutation) Genotype I, O I, OC IS, O I, O Is, Oc Lactose present No No Yes Yes No Repressed (yes/no) N VAS ves NO Constitutive (yes/no) NO NO YES Yes NO Inducible (yes/no) Yes yes NO NO YUS
- 1. If the above gene is one of the three structural genes of the lac operon that codes for theprotein/ enzyme responsible for breaking lactose into two molecules of simple sugars,a.) what triggers the activation of this gene?b.) what triggers the inactivation of this gene?c.) what substance is attached to the operator region of the operon in the absence ofactivator?d.) what gene is responsible for the synthesis of the substance used to attach in theoperator region in the absence of activator? e.) what substance is attached to the promoter region of the operon in this case?1) The UR operon which is composed of sequences A, B, C, and D (which may or may not be genes of regulatory sequences), encodes enzymes 1 and 2. Mutations in sequences A, B, C, and D have the following effects listed in the table below. A plus sign (+) indicates that the enzyme is synthesized and a minus sign (-) indicates that the enzyme is not synthesize. Mutation in UR present UR absent Enzyme 1 Enzyme 2 Enzyme 1 Enzyme 2 sequence No Mutation + + A + B + + + + C + D A) Is the UR operon inducible or repressible? B) Indicate which sequence (A, B, C, or D) is part of the following components of the operon: a. Regulator gene b. Promoter c. Structural gene for Enzyme 1 d. Structural gene for Enzyme 224. What statement is NOT true regarding transcription attenuation of amino acid biosynthetic operons? 1.The leader peptide will contain multiple instances of the amino acid produced by the operon. 2.Transcription attenuation will always be accompanied by other positive or negative regulatory mechanisms. 3.Trancription will be reduced under conditions where concentration of the amino acid produced by the operon is high. 4.Synthesis of the leader peptide depends on the concentration of the aminoacylated tRNA, not the amino acid directly. 5.All of these statements are true.