Question 1

The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following developmental events would occur?

Accepted Answer

A)   The embryo would grow extra wings and legs.
B)   The embryo would probably show no anterior development and die.
C)   Anterior structures would form in both ends of the embryo.
D)   The embryo would develop normally.

Question 2

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then

Accepted Answer

A)   the amino acid inactivates the repressor.
B)   the repressor is active in the absence of the amino acid.
C)   the amino acid acts as a corepressor.
D)   the amino acid turns on transcription of the operon.

Question 3

Among the newly discovered small noncoding RNAs, one type helps to reestablish ethylation patterns during gamete formation and blocks expression of some transposons. Which of the following types of RNA is responsible for this function?

Accepted Answer

A)   miRNA
B)   piRNA
C)   lncRNA
D)   siRNA

Question 4

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments, she succeeded in increasing acetylation of histone tails in the chromatin of the cells. Which of the following results would she most likely see in these cells?

Accepted Answer

A)   increased chromatin condensation
B)   decreased chromatin condensation
C)   decreased binding of transcription factors
D)   inactivation of the selected genes

Question 5

Which of the following processes would result from a mutation that deactivates a regulatory gene of a repressible operon in an E. coli cell?

Accepted Answer

A)   continuous transcription of the structural gene controlled by that regulator
B)   complete inhibition of transcription of the structural gene controlled by that regulator
C)   irreversible binding of the repressor to the operator
D)   continuous translation of the mRNA because of alteration of its structure

Question 6

Which of the following are maternal effect genes that control the orientation of the egg and thus the Drosophila embryo?

Accepted Answer

A)   homeotic genes
B)   segmentation genes
C)   egg-polarity genes
D)   morphogens

Question 7

Within a cell, the amount of protein made using a given mRNA molecule depends partly on

Accepted Answer

A)   the degree of DNA methylation.
B)   the rate at which the mRNA is degraded.
C)   the number of introns present in the mRNA.
D)   the types of ribosomes present in the cytoplasm.

Question 8

For a repressible operon to be transcribed, which of the following conditions must occur?

Accepted Answer

A)   A corepressor must be present.
B)   RNA polymerase and the active repressor must be present.
C)   RNA polymerase must bind to the promoter, and the repressor must be inactive.
D)   RNA polymerase must not occupy the promoter, and the repressor must be inactive.

Question 9

DNA methylation and histone acetylation are examples of which of the following processes?

Accepted Answer

A)   genetic mutation
B)   chromosomal rearrangements
C)   epigenetic phenomena
D)   translocation

Question 10

Which of the following conditions is most likely to cause the lactose operon to be transcribed?

Accepted Answer

A)   There is more glucose in the cell than lactose.
B)   There is glucose but no lactose in the cell.
C)   The cyclic AMP and lactose levels are both high within the cell.
D)   The cAMP level is high and the lactose level is low.

Question 11

Which of the following mechanisms is used to coordinate the expression of multiple, related genes in eukaryotic cells?

Accepted Answer

A)   Environmental signals enter the cell and bind directly to promoters.
B)   A given gene may have multiple enhancers, but each enhancer is generally associated with only that gene and no other.
C)   The genes are organized into a large operon, allowing them to be coordinately controlled as a single unit.
D)   A single repressor is able to turn off several related genes.

Question 12

According to the lac operon model proposed by Jacob and Monod, what is predicted to occur if the operator is removed from the operon?

Accepted Answer

A)   The lac operon would be transcribed continuously.
B)   Only lacZ would be transcribed.
C)   Only lacY would be transcribed.
D)   Galactosidase permease would be produced, but would be incapable of transporting lactose.

Question 13

When the Bicoid protein is expressed in Drosophila, divisions between cells in the embryo are not yet fully developed. This information helps to explain which observation by Nüsslein-Volhard and Wieschaus?

Accepted Answer

A)   mRNA from the egg is translated into the Bicoid protein.
B)   Bicoid protein diffuses throughout the embryo in a concentration gradient.
C)   Bicoid protein serves as a transcription regulator.
D)   Bicoid protein determines the dorso-ventral axis of the embryo.

Question 14

The cAMP receptor protein (CRP)  is said to be responsible for positive regulation of the lac operon because ________.

Accepted Answer

A)   CRP binds cAMP
B)   CRP binds to the CAP-binding site
C)   CRP prevents binding of the repressor to the operator
D)   CRP bound to the CRP-binding site stimulates the transcription of the lac operon

Question 15

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If a researcher moves the repressor gene (lacI) , along with its promoter, to a position at some several thousand base pairs away from its normal position, which of the following results would be expected?

Accepted Answer

A)   The repressor will no longer bind to the operator.
B)   The repressor will no longer bind to the inducer.
C)   The lac operon will be expressed continuously.
D)   The lac operon will function normally.

Question 16

There is a mutation that is found in E. coli in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of the following characteristics would you expect to observe in such a mutant?

Accepted Answer

A)   It cannot bind to the operator.
B)   It cannot make a functional repressor.
C)   It cannot bind to the inducer.
D)   It makes a repressor that binds CAP.

Question 17

Mutations in which of the following genes lead to transformations in the identity of entire body parts?

Accepted Answer

A)   segmentation genes
B)   egg-polarity genes
C)   homeotic genes
D)   inducers

Question 18

The fact that plants can be cloned from somatic cells demonstrates that ________.

Accepted Answer

A)   differentiated cells retain all the genes of the zygote
B)   genes are lost during differentiation
C)   the differentiated state is normally very unstable
D)   differentiation does not occur in plants

Question 19

Which of the following is an example of post-transcriptional control of gene expression?

Accepted Answer

A)   the addition of methyl groups to cytosine bases of DNA
B)   the binding of transcription factors to a promoter
C)   the removal of introns and alternative splicing of exons
D)   gene amplification contributing to cancer

Question 20

Which of the following processes do normal proto-oncogenes typically exhibit?

Accepted Answer

A)   They normally suppress tumor growth.
B)   They enhance tumor growth.
C)   They stimulate normal cell growth and division.
D)   They are underexpressed in cancer cells.

Exam 18: Regulation of Gene Expression

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then

Correct Answer
verified

Among the newly discovered small noncoding RNAs, one type helps to reestablish ethylation patterns during gamete formation and blocks expression of some transposons. Which of the following types of RNA is responsible for this function?

Correct Answer
verified

When the Bicoid protein is expressed in Drosophila, divisions between cells in the embryo are not yet fully developed. This information helps to explain which observation by Nüsslein-Volhard and Wieschaus?

Correct Answer
verified

For a repressible operon to be transcribed, which of the following conditions must occur?

Correct Answer
verified

Which of the following processes do normal proto-oncogenes typically exhibit?

Correct Answer
verified

According to the lac operon model proposed by Jacob and Monod, what is predicted to occur if the operator is removed from the operon?

Correct Answer
verified

Which of the following mechanisms is used to coordinate the expression of multiple, related genes in eukaryotic cells?

Correct Answer
verified

DNA methylation and histone acetylation are examples of which of the following processes?

Correct Answer
verified

The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following developmental events would occur?

Correct Answer
verified

Which of the following processes would result from a mutation that deactivates a regulatory gene of a repressible operon in an E. coli cell?

Correct Answer
verified

Correct Answer
verified

Which of the following are maternal effect genes that control the orientation of the egg and thus the Drosophila embryo?

Correct Answer
verified

Which of the following conditions is most likely to cause the lactose operon to be transcribed?

Correct Answer
verified

The fact that plants can be cloned from somatic cells demonstrates that ________.

Correct Answer
verified

The cAMP receptor protein (CRP) is said to be responsible for positive regulation of the lac operon because ________.

Correct Answer
verified

Correct Answer
verified

There is a mutation that is found in E. coli in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of the following characteristics would you expect to observe in such a mutant?

Correct Answer
verified

Mutations in which of the following genes lead to transformations in the identity of entire body parts?

Correct Answer
verified

Which of the following is an example of post-transcriptional control of gene expression?

Correct Answer
verified

Within a cell, the amount of protein made using a given mRNA molecule depends partly on

Correct Answer
verified

Exam 18: Regulation of Gene Expression

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then

Correct AnswerverifiedShow Answer

Among the newly discovered small noncoding RNAs, one type helps to reestablish ethylation patterns during gamete formation and blocks expression of some transposons. Which of the following types of RNA is responsible for this function?

Correct AnswerverifiedShow Answer

When the Bicoid protein is expressed in Drosophila, divisions between cells in the embryo are not yet fully developed. This information helps to explain which observation by Nüsslein-Volhard and Wieschaus?

Correct AnswerverifiedShow Answer

For a repressible operon to be transcribed, which of the following conditions must occur?

Correct AnswerverifiedShow Answer

Which of the following processes do normal proto-oncogenes typically exhibit?

Correct AnswerverifiedShow Answer

According to the lac operon model proposed by Jacob and Monod, what is predicted to occur if the operator is removed from the operon?

Correct AnswerverifiedShow Answer

Which of the following mechanisms is used to coordinate the expression of multiple, related genes in eukaryotic cells?

Correct AnswerverifiedShow Answer

DNA methylation and histone acetylation are examples of which of the following processes?

Correct AnswerverifiedShow Answer

The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following developmental events would occur?

Correct AnswerverifiedShow Answer

Which of the following processes would result from a mutation that deactivates a regulatory gene of a repressible operon in an E. coli cell?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following are maternal effect genes that control the orientation of the egg and thus the Drosophila embryo?

Correct AnswerverifiedShow Answer

Which of the following conditions is most likely to cause the lactose operon to be transcribed?

Correct AnswerverifiedShow Answer

The fact that plants can be cloned from somatic cells demonstrates that ________.

Correct AnswerverifiedShow Answer

The cAMP receptor protein (CRP) is said to be responsible for positive regulation of the lac operon because ________.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

There is a mutation that is found in E. coli in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of the following characteristics would you expect to observe in such a mutant?

Correct AnswerverifiedShow Answer

Mutations in which of the following genes lead to transformations in the identity of entire body parts?

Correct AnswerverifiedShow Answer

Which of the following is an example of post-transcriptional control of gene expression?

Correct AnswerverifiedShow Answer

Within a cell, the amount of protein made using a given mRNA molecule depends partly on

Correct AnswerverifiedShow Answer

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