Gene expression

Question 1

All Cells Must Precisely Regulate The Expression Of Genes To

Answer 1

Function As Coherent Biological Systems

Question 2

This Ability Is Essential For All
Cells To Produce The Specific Set
Of Proteins & Specialized RNA
Molecules They Require To
Function

Answer 2

Independently As A Single-Cell species &
As A Critical Part Of A Multi-Cell
Species Like Us

Question 3

Precise Gene Expression Enables Cells To

Answer 3

Maintain All Proteins & Specialized RNA Molecules At The
Proper Concentration

Question 4

Each Of The 220 Human Cell Types Must Express A Unique Pattern Of Genes To

Answer 4

Produce The Distinctive Set Of Proteins & Specialized RNA Molecules It Needs To
Perform Its Bodily Function

Question 5

The Gene Is Activated When The Cell Needs The Protein

Answer 5

the Gene Encodes Or Needs A Higher
Concentration

Question 6

The Gene Is Deactivated When The Cell

Answer 6

Does Not Need The Protein The Gene Encodes
* Has The Proper Concentration Of The Protein The Gene Encodes

Question 7

When A Receptor Recognizes An
Environmental Factor,

Answer 7

The Cell
Expresses The Genes That Code For
The Proteins The Cell Requires To
Respond To That Environmental Factor

Question 8

The Operon

Answer 8

Is A Group Of Related Genes Clustered Together On The
Prokaryotic (Archaea & Bacteria) Chromosome

Question 9

The Genes In The Operon Code For

Answer 9

Related Proteins That Perform A Specific
Cellular Function, Such As, Lactose Metabolism
The Lac Operon Of The
Bacterium, E. coli, That
Inhabits Your Lower
Intestine

Question 10

Arranging Related Genes Into An Operon Facilitates

Answer 10

The Expression Of
Gene Regulation, Conserves Energy, And Conserves Molecular
Building Blocks

Question 11

All Genes In An Operon Are Expressed (Activated) Or Repressed (Deactivated) As A Single
Unit Because

Answer 11

One Promoter Controls The Transcription Of All The Operon’s Genes

Question 12

Only One Molecular Switch Is Required To

Answer 12

Regulate Operon Expression

Question 13

After Translation, All The Proteins Required To
Catabolize Lactose Are

Answer 13

Clustered Together In The Cell

Question 14

The Lac Operon Of The Bacterium Escherichia coli (E. coli

Answer 14

-E. coli Inhabits The Lower Human Intestine
- E. coli Has Access To The Nutrients In Breast Milk & Other Dairy Products
-The Lac (Lactose) Operon Enables E. coli To Metabolize Lactose (Milk Sugar)

Question 15

The Lac Z Gene Codes For The

Answer 15

Beta-Galactosidase Enzyme That Cleaves Lactose To
Produce Glucose & Galactose

Question 16

We Produce Lactase In The Small Intestine To Digest

Answer 16

Lactose In Dairy Products

Question 17

The Lac Y Gene Codes For The

Answer 17

The Membrane Transport Protein, Permease, That Imports
Lactose

Question 18

The Lac A Gene Codes For

Answer 18

Transacetylase Enzyme That Protects The Cell By Detoxifying
Poisonous Β-Galactosides & Increasing Their Export

Question 19

The Promoter & Operator Are

Answer 19

The DNA Regulatory Elements That
Control Lac Operon Expression

Question 20

Transcription Factors & RNA Polymerase Bind To

Answer 20

The Promoter To Enable
(Promote) Transcription

Question 21

The Regulatory Lac I Repressor Protein Binds To The

Answer 21

Operator To Repress
Transcription

Question 22

The Lac I Repressor Protein Is Required For

Answer 22

E. coli To Control
Lac Operon Expression

Question 23

This Regulatory Protein Is
Encoded By The Lac I Gene

Answer 23

The Lac I Gene Is Not Part Of The
Lac Operon

Question 24

When the Lac I Repressor Protein

Answer 24

-Binds To The Operator, The Lac
Operon Is Repressed Because RNA
Polymerase Cannot Bind To The
Promoter
-Does Not Bind To The Operator,
The Lac Operon Is Expressed
Because RNA Polymerase Binds To
The Promoter

Question 25

The Lac Operon Is The

Answer 25

First Model Based On Actual Data To Explain
How Cells Regulate Gene Expression

Question 26

When Lactose Is Unavailable,

Answer 26

E. coli Represses The Lac Operon

Question 27

Expression Without Lactose Would Waste The?

Answer 27

The Resources (Energy, Nucleotides, Amino
Acids) Required To Perform Transcription & Translation

Question 27

he Lac Operon Is

Answer 27

Repressed Without Lactose

Question 27

When There Are No Lactose
Molecules In The Bacterium,
The

Answer 27

Lac I Repressor Protein Binds To
The Operator
* RNA Polymerase Enzyme
Cannot Bind To The Promoter
* Lac Operon Is “Repressed”

Question 28

The Lac Operon Is Expressed With

Answer 28

Lactose In The Cell

Question 28

Lactose Binds To The Lac I Repressor Protein

Answer 28

The Lac I Repressor Protein Is Inactivated
* The Inactivated Lac I Repressor Protein Cannot Bind To The Operator
* RNA Polymerase Binds To The Promoter & Transcribes The Three Genes