How does the repressor protein contribute to selective expression of the structural genes Z, Y, and A in the lac operon?   The repressor protein is only expressed when lactose is present. The repressor is always expressed. It blocks transcription when lactose is present. The repressor is always expressed. It allows transcription when lactose is absent. The repressor is always expressed. It blocks transcription when lactose is absent. The repressor protein is only expressed when lactose is absent.

Q: The map of the lac operon is shown below. Consider the following examples that include both haploids…

A: Lac operon is the segment of DNA which includes regulatory gene, structural gene, promoter gene and…

Q: Imagine that you are studying the promoters of genes in E. coli. You notice that genes that are…

A: Lac operon in E.coli. is negatively inducible operon. It has 3 structural genes - LacZ - encodes…

Q: In the lac operon (below), how will expression of the genes lacZ and lacy be effect by a mutation in…

A: Lac operon includes the genes that code for the enzymes involved in the catabolism of lactose sugar.…

Q: Which of the following statements about the trp operon is false?

A: From above question the statement  If a mutation in region 2 prevents the formation of the 2 + 3…

Q: In the lac operon of E. coli, if glucose levels increase while lactose levels decrease, what will…

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

Q: Which of the following conditions is most likely to result in an increase rate of transcription of…

A: Lactose in bacteria is called beta-galactoside which is used as energy and as a carbon source.…

Q: You identify a mutant that affects lac operon expression. You decide to investigate this mutant…

A: The concept of transcriptional regulation refers to the mechanisms by which cells control the…

Q: A bacterial cell is mutated and cannot create the repressor protein associated with the Lac operon.…

A: Lac operon is associated with uptake and metabolism of lactose. It has several components such as a…

Q: e following genetic and cellular conditions.  You do not need to consider the role of CAP in your…

A: Upper operon -  Is is super repressor. Once it is present in the sequence, it can not be removed. If…

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: 5f. Complete the diagrams below to reflect the proteins and any relevant cofactors (e.g. -…

A: The lac operon is an operon, or cluster of genes with one promoter (transcribed as one mRNA). The…

Q: cAMP binds to cAMP Receptor Protein (CRP), allowing CRP to bind to the promoter of the lac operon

A: Almost all bacteria such as E. coli contains lac operon which operates in utilization of lactose as…

Q: A mutation in the lac I gene that prevents production of the lac repressor choose an answer below:…

A: lac operon also known as lactose operon was discovered by F. Jacob and J. Monod, for that, they…

Q: Consider a mutant of E. coli that has an inactivating mutation in the gene for adenylate cyclase…

A: Introduction :- Inactivating mutations, also known as loss-of-function mutations, cause the gene…

Q: Describe the main functional differences between the TRP and the Lac operons. Main functional…

A: TRP stands for tryptophan. It is an essential amino acid that must be obtained from the diet and is…

Q: An E. coli cell acquires a mutation in the gene that encodes CAP. The mutation affects the…

A: The transcription is a process through which information in the DNA molecule is transcribed into…

Q: For the following types of transcriptional control, indicate whether the protein produced by the…

A: An inducible operon is one which is not transcribed. For transcription of the molecule, it requires…

Q: A mutation in the trp repressor gene that prevents the apo-repressor from binding the co-repressor…

A: Tryptophan operon Tryptophan operon is negatively regulated operon, it includes five gene, promotor,…

Q: 5f. Complete the diagrams below to reflect the proteins and any relevant cofactors (e.g. -…

A:

Q: Does it need active form or inactive form of the repressor ? 3) What is role of RNA polymerase,…

A: An operon is defined as the collection of coordinately regulated genes . Q2Ans:In a negative control…

Q: One way that regulation is often studied is by examining the effects of mute ons. For example,…

A: There are two types of lac mutations occurring in lac operon: 1. uninducible - operon can't be…

Q: As diagrammed below, some amino acid biosynthetic operons have stem loop structures in the mRNA.…

A: Option A is incorrect as without the formation of heparin the process of translation can not be…

Q: What experimental results would indicate that the mutation lacISlacIS is dominant to lacI+lacI+?…

A: The lac operon is a set of genes that are responsible for the metabolism of lactose in bacteria. The…

Q: The DNA sequence before the protein coding region that determines when a gene is used is called the…

A: DNA is the genetic material of many organisms including the humans. The DNA contains information…

Q: Consider the trp operon found in E. coli. You have discovered a mutant strain of E.coli that…

A: The genome of the prokaryotic organisms is polycistronic i.e. the genes are controlled by one…

Q: P*O*Z*Y# Example lac+ I*p*o+z*Y* FP*0*Z*Y* IP*o*z*Y* -P#O*Z¥Y* I*p*oCz*Y C I*p*o+z*Y

A: The lac operon is a catabolic operon and is expressed in the presence of the inducer lactose.

Q: You have isolated different mutants (reg1 and reg2) causing constitutive expression of the emu…

A: In this question, we are given with a situation in which the DNA has two mutation reg1 and reg2.…

Q: The lac operon has which of the following characteristics? O 1) usually requires an activator…

A: In Eukaryotes all genes are separate and produce individual mRNAs on transcription. However, in…

Q: Tryptophan (Trp) attenuation is an extra mechanism of regulation of trp operon when trp level is too…

A: The trp Operon, is nothing but a sequence of DNA that is responsible for the regulation of formation…

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.