Biological Science (7th Edition)
Biological Science (7th Edition)
7th Edition
ISBN: 9780134678320
Author: Scott Freeman, Kim Quillin, Lizabeth Allison, Michael Black, Greg Podgorski, Emily Taylor, Jeff Carmichael
Publisher: PEARSON
bartleby

Concept explainers

bartleby

Videos

Question
Book Icon
Chapter 18, Problem 1TYK
Summary Introduction

Introduction:

The genes that are involved in the regulation of the lactose metabolism are found to be present in the single sequence. These sequences are regulated by a single promoter site.

Expert Solution & Answer
Check Mark

Answer to Problem 1TYK

Correct answer:

Genes involved in the metabolism of the lactose are considered to be an operon because they are controlled by the same promoter. The operon is the gene segment, which is controlled by the same promoter.

Explanation of Solution

Explanation/Justification for the correct answer:

Option (d) gives that the genes are all controlled by the same promoter. The entire structural genes that encode enzymes required to use lactose as an energy source lie adjacent to each other in the lactose (or lac) operon under the control of a single lac promoter. Hence, Option (d) is correct.

Explanation for incorrect answers:

Option (a) gives that the genes occupy adjacent locations on the E. coli chromosome. The gene sequence, which regulates the metabolism of the lactose, is not located adjacently; they are located on the same DNA (deoxyribonucleic acid) sequence. So, it is an incorrect option.

Option (b) gives that the genes have a similar function. The genes that are involved in the metabolism of the lactose have different functions. They are involved in the secretion of different enzymes. So, it is an incorrect option.

Option (c) gives that the genes are all required for normal cell functioning. These genes are not required for the normal metabolism of the lactose in the cell. The operons are only responsible for the regulation of the genes. So, it is an incorrect option.

Hence, options (a), (b), and (c) are incorrect.

Conclusion

All the genes involved in the metabolism of the lactose are controlled by the same promoter and are called operon.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Operons involved with the biosynthesis of molecules such as amino acids are most likely to be regulated in which of the following ways? a. The product of the biosynthetic pathway represses transcription. b. The product of the biosynthetic pathway activates transcription. c. A precursor of the biosynthetic pathway represses transcription. d. A precursor of the biosynthetic pathway activates transcription.
Operons can not be:   a. Negatively regulated b. Positively regulated c. Constitutive d. Inducible e. Repressible f. coding for related structural proteins g. Expressed by use of RNA polymerase h. Dependent on a promoter for expression
What is the role of a substrate that controls a repressible operon?   a. increase the production of inactive repressor proteins   b. bind to the repressor protein and activate it   c. bind to the repressor protein and deactivate it   d. bind to the promoter region and decrease the affinity of RNA polymerase for the promoter
Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
  • Text book image
    Biology (MindTap Course List)
    Biology
    ISBN:9781337392938
    Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg
    Publisher:Cengage Learning
Text book image
Biology (MindTap Course List)
Biology
ISBN:9781337392938
Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg
Publisher:Cengage Learning
QCE Biology: Introduction to Gene Expression; Author: Atomi;https://www.youtube.com/watch?v=a7hydUtCIJk;License: Standard YouTube License, CC-BY