Question

Which of the following statements about regulation of the lac operon is true? Select all that...

Which of the following statements about regulation of the lac operon is true? Select all that apply.

Group of answer choices

When glucose is present but lactose is absent, gene expression is activated at the lac operon.

The presence of glucose in the growth medium does not affect the level of gene expression activated by the presence of lactose.

The lac repressor can dissociate from the operator in the presence of glucose.

Gene expression is high when the lac repressor is not bound to the operator and glucose is unavailable.

Gene expression is high when the lac repressor is not bound to the operator and glucose and lactose are available.

Science   Biology   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

True statements:

1. The lac repressor can dissociate from the operator in the presence of glucose.

2. Gene expression is high when the lac repressor is not bound to the operator and glucose is unavailable.

False statement :

1. When glucose is present but lactose is absent, gene expression is activated at the lac operon. (No, gene activation requires lactose).

2 .The presence of glucose in the growth medium does not affect the level of gene expression activated by the presence of lactose.(present of glucose decreases the gene expression of lactose, since there will be no cAMP, which up regulate the gene expression)

3. Gene expression is high when the lac repressor is not bound to the operator and glucose and lactose are available.(no gene expression will be done, if there is no lactose).

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
1. The lac operon responds to lactose and glucose. If wild-type E. coli cells are grown...
1. The lac operon responds to lactose and glucose. If wild-type E. coli cells are grown in media that contains both lactose and glucose, they will consume the glucose first because: (select all that apply) A.) the lac repressor remains bound to lacO, preventing the lac operon from being expressed at maximal levels B.) the permease (lacY) is not expressed in the presence of glucose, preventing lactose from entering the cell and being converted to allolactose, the inducer C.) the...
The lac operon consists of several genes that encode enzymes required for metabolizing lactose. The expression...
The lac operon consists of several genes that encode enzymes required for metabolizing lactose. The expression of the lac operon is regulated by the presence of lactose and glucose. 1) describe the regulation operon when the level of glucose is high and the level of lactose is low
The lac operon in E. coli regulates the co-expression of three genes needed for the degradation...
The lac operon in E. coli regulates the co-expression of three genes needed for the degradation of lactose (but absence of glucose) in the growth medium. These genes are not expressed when the bacteria has no lactose to feed on. How does the cell prevent expressing the lac operon in the absence of lactose? How does the presence of lactose activate the transcription of these three genes? (You do not need to explain the glucose level regulation.)
Which of the following accurately describes the status of lac operon regulation when E. coli cells...
Which of the following accurately describes the status of lac operon regulation when E. coli cells shift from using glucose to lactose as their carbon source? A. The lac repressor is active and the CAP protein is active, so the operon is transcribed B. The lac repressor is active and the CAP protein is inactive, so the operon is transcribed C. The lac repressor is inactive and the CAP protein is active, so the operon is transcribed D. The lac...
Compare the regulation of the lac operon and the effect on the production of ß-galactosidae when...
Compare the regulation of the lac operon and the effect on the production of ß-galactosidae when E. coli is grown under the following conditions: a) In the presence of high levels of lactose and absence of glucose b) In the presence of high levels of lactose and high levels of glucose
1.    The lac operon in E. coli comprises three structural genes, lac Z, lacY, and lacA....
1.    The lac operon in E. coli comprises three structural genes, lac Z, lacY, and lacA. It is regulated by both positive and negative mechanisms, involving binding of both a repressor protein and the catabolite activator protein (CAP). Transcription of the operon gives a polycistronic mRNA encoding the three enzymes. Under the following nutritional conditions, indicate whether or not the repressor and the CAP are bound by drawing them in on the appropriate regions of the operon. Indicate, as well,...
1. A lac operon of genotype lacI- lacP+ lacO+ lacZ- lacY+ will produce b-galactosidase AND permease...
1. A lac operon of genotype lacI- lacP+ lacO+ lacZ- lacY+ will produce b-galactosidase AND permease when lactose is present lactose is absent in the presence OR absence of lactose when glucose is present never 2. A lac operon of genotype lacI+ lacP+ lacO+ lacZ+ lacY- will produce b-galactosidase BUT NOT permease when lactose is present lactose is absent in the presence OR absence of lactose when glucose is present all of the above
1.)The lac operon is inducible by the presence of lactose. Loss-of-function mutations in the lacI gene,...
1.)The lac operon is inducible by the presence of lactose. Loss-of-function mutations in the lacI gene, which encodes the lac repressor (pick all that apply): A.)slow down the isomerization of lactose into allolactose B.)decrease the amount of permease activity in the cell in the presence of lactose. C.)prevent loss-of-function lacZ mutations from making the lac operon uninducible D.)are recessive to wild type 2.)Mutations that eliminate the lacO operator site (pick all that apply): A.)slow down the isomerization of lactose into...
If E. coli were subjected to high levels of lactose and low levels of glucose, which...
If E. coli were subjected to high levels of lactose and low levels of glucose, which of the following conditions would apply? Y = yes, N = no A) lac repressor would be bound to the operator of the lac operon promoter B) CAP protein would be bound to the CAP binding site adjacent to the lac operon promoter C) cAMP levels would be low D) the lac operon would be actively expressing the operon into separate mRNA molecules needed...
A bacterial strain expresses a mutant lac repressor protein that retains its ability to bind to...
A bacterial strain expresses a mutant lac repressor protein that retains its ability to bind to the operator but cannot bind lactose. What is the effect on gene expression in these mutants? What happens when lactose is added to the growth medium?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT