Gene regulation governing lactose operon of E. coli that involves the lac I gene products is:

1. positive and inducible because it can be induced by lactose.
2. negative and inducible because repress or protein prevents transcription.
3. negative and repressible because repress or protein prevents transcription.
4. feedback inhibition because excess of β galactosidase can switch off transcription.

Subtopic:  Gene Regulation: Lac Operon |
 52%
NEET - 2015
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Which enzyme(s) will be produced in a cell in which there is a non-sense mutation in the lac Y gene?

1.  Lactose permease
2.  Transacetylase
3.  Lactose permease and transacetylase
4.  β - galactosidase

Subtopic:  Gene Regulation: Lac Operon |
From NCERT
AIPMT - 2013
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

In an inducible operon, the genes are:
1. usually not expressed unless a signal turns them "on"
2. usually expressed unless a signal turns them "off"
3. never expressed
4. always expressed
Subtopic:  Gene Regulation: Lac Operon |
 68%
From NCERT
NEET - 2013
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

Read the following four statements (A-D):

A. In transcription, adenosine pairs with uracil
B. Regulation of lac operon by a repressor is referred to as positive regulation
C. The human genome has approximately 50,000 genes
D. Haemophilia is a sex-linked recessive disease


How many of the above statements are right?

1.  Three 

2.  Four 

3.  One 

4.  Two 

Subtopic:  Gene Regulation: Lac Operon | Human Genome Project | Transcription |
 56%
From NCERT
AIPMT - 2012
Please attempt this question first.
Hints
Please attempt this question first.

Select the two correct statements out of the four (a-d) given below about lac operon:

a: Glucose or galactose may bind with the repressor and inactivate it.
b: In the absence of lactose, the repressor binds with the operator region.
c: The z-gene codes for permease.
d: It was explained by Francois Jacob and Jacque Monod.

The correct statements are:

1. (b) and (c)
2. (a) and (c)
3. (b) and (d)
4. (a) and (b)
Subtopic:  Gene Regulation: Lac Operon |
 86%
From NCERT
AIPMT - 2010
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The lac Operon consists of:

1. One regulatory gene and three structural genes
2. Two regulatory genes and two structural genes
3. Three regulatory genes and three structure genes
4. Four regulatory genes only
Subtopic:  Gene Regulation: Lac Operon |
 88%
From NCERT
AIPMT - 2010
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

advertisementadvertisement