Control Of Gene Expression

Question 1

Regulatory Gene

Answer 1

DNA sequence that encodes a protein or RNA molecule that interacts with other DNA sequences and affects transcription or translation of those sequences.

Question 2

Structural Gene

Answer 2

DNA sequence that encodes a protein that functions in metabolism or biosynthesis or that has a structural role in the cell.

Question 3

Regulatory Element

Answer 3

DNA sequence that affects the transcription of other DNA sequences to which it is physically linked.

Question 4

Gene Regulation

Answer 4

Mechanisms and systems that control the expression of genes.

Question 5

Constitutive Gene

Answer 5

A gene that is expressed continually without regulation.

Question 6

Levels Of Gene Regulation

Answer 6

Epigenetic, transcriptional, post-transcriptional, translational, and post-translational.

Question 7

Regulator Protein

Answer 7

Protein produced by a regulator gene that binds to another DNA sequence and controls the transcription of other genes.

Question 8

Operon

Answer 8

A group of bacterial structural genes that are transcribed together, along with their promoter and additional sequences that control their transcription.

Question 9

Regulator Gene

Answer 9

Gene associated with an operon in bacterial cells that encodes a protein or RNA molecule that functions in controlling the transcription of other genes.

Question 10

Operator

Answer 10

DNA sequence in an operon to which a regulator protein binds; this binding affects the rate of transcription of the structural genes.

Question 11

Positive Control

Answer 11

Transcriptional control in which a regulatory protein is an activator, stimulating transcription.

Question 12

Negative Control

Answer 12

Transcriptional control in which a regulatory protein is a repressor, binding to DNA and inhibiting transcription.

Question 13

Inducible Operon

Answer 13

Operon in which transcription is normally off (not taking place); something must happen to induce transcription, or turn it on.

Question 14

Inducer

Answer 14

Substance that stimulates transcription in an inducible system of gene regulation; usually a small molecule that binds to a repressor protein and alters that repressor so that it can no longer bind to DNA and inhibit transcription.

Question 15

Repressible Operon

Answer 15

Operon in which transcription is normally on (taking place); something must happen to repress transcription, or turn it off.

Question 16

Corepressor

Answer 16

Substance that inhibits transcription in a repressible system of gene regulation; usually a small molecule that binds to a repressor protein and alters it so that the repressor is able to bind to DNA and inhibit transcription.

Question 17

Catabolite Activator Protein (CAP)

Answer 17

Protein that functions in catabolite repression. When bound with cAMP, it binds to the promoters of certain operons and stimulates transcription.

Question 18

RNA Interference

Answer 18

Process in which cleavage of double-stranded RNA produces small RNAs (siRNAs or miRNAs) that bind to mRNAs containing complementary sequences and bring about their cleavage and degradation thereby silencing expression.

Question 19

cAMP

Answer 19

Modified nucleotide that functions in catabolite repression. Low levels of glucose stimulate high levels of it; it then attaches to CAP, which binds to the promoters of certain operons and stimulates transcription.

Question 20

Chromatin Remodeling Complex

Answer 20

Complex of proteins that bind directly to particular sites on DNA and reposition the nucleosomes, allowing other transcription factors and RNA polymerase to bind to promoters and initiate transcription.

Question 21

Histone Code

Answer 21

Modifications of histone proteins, such as the addition or removal of phosphate groups, methyl groups, or acetyl groups, that encode information affecting how genes are expressed.

Question 22

Trp Operon

Answer 22

A group of genes that are transcribed together, encoding the enzymes that produce the amino acid tryptophan in bacteria.

Question 23

Genomic Imprinting

Answer 23

Differential expression of a gene depending on whether it is inherited from the male or female parent.

Question 24

Lac Operon

Answer 24

A group of genes required for the transport and metabolism of lactose in bacteria like E. coli.

Question 25

Epigenetics

Answer 25

Phenomena due to alterations in DNA that do not include changes in the base sequence; often affects the way in which DNA sequences are expressed. Such alterations are often stable and heritable in the sense that they are passed to descendant cells or individuals.

Question 26

DNA Methylation

Answer 26

Modification of DNA by the addition of methyl groups by specific enzymes to certain positions on the bases.