Question 1

In thinking about their role in cell division, oncogenes are like the ________ of a car, while tumor-suppressor genes are like the ________ of a car.

Accepted Answer

A)   gas pedal; brakes
B)   steering wheel; brakes
C)   gas pedal; headlights
D)   brakes; gas pedal

Question 2

RNA splicing involves the

Accepted Answer

A)   addition of a nucleotide "cap" to the molecule.
B)   addition of a nucleotide "tail" to the molecule.
C)   removal of introns from the molecule.
D)   removal of exons from the molecule.

Question 3

A gene operon consists of

Accepted Answer

A)   a transcribed gene only.
B)   a promoter only.
C)   a regulatory gene only.
D)   transcribed genes, an operator, and a promoter.

Question 4

Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.

Accepted Answer

A)   activators
B)   enhancers
C)   transcription factors
D)   RNA polymerase

Question 5

While DNA microarrays can be used to determine whether or not a gene is expressed in a cell, quantitative polymerase chain reaction (qPCR)  can be used to specifically quantify the extent of gene expression in cells and tissues. To perform qPCR, mRNA is extracted from cells and reverse transcribed to complementary DNA (cDNA) . Using fluorescent DNA molecules that recognize specific gene sequences and DNA polymerase, copies of the gene sequence of interest are made. After the copies are made, a fluorescent detector measures the intensity of the fluorescent signal, which is proportional to the number of mRNA transcripts in the cell and corresponds to the level of gene expression in the cell.
-Which of the following statements regarding the comparison of DNA microarrays and qPCR is false?

Accepted Answer

A)   Both methods use fluorescent DNA molecules and cDNA.
B)   Both methods can determine whether a gene has been turned on or not.
C)   Both methods use mRNA extracted from cells.
D)   Both methods can accurately quantify the levels of gene expression in cells.

Question 6

Gene knockdown is a procedure used to reduce gene expression in cells or organisms so that scientists can investigate gene function. While there are several ways to knock down gene expression, RNAi is one of the most commonly used approaches. Suppose that a research team wants to investigate where a new gene X is expressed in the fruit fly, Drosophila melanogaster. Using RNAi, they obtained the results shown below examining the expression of gene X in four types of tissues.
-Which of the following components could the researchers have used to successfully perform RNAi against gene X?

Accepted Answer

A)   an siRNA molecule that has a complementary sequence to that of gene X
B)   a transcription factor that binds to and activates the gene X promoter
C)   an enzyme that helps fold the X protein after it is translated

Question 7

Mutations in the p53 gene can lead to cancer by

Accepted Answer

A)   causing the production of excessive amounts of relay proteins.
B)   causing the production of a faulty protein that is no longer able to inhibit cell division.
C)   promoting the expression of mRNA that can interact with DNA, resulting in new mutations.
D)   increasing the production of growth hormones, which trigger faster cell cycles.

Question 8

Which statement about microarrays is false?

Accepted Answer

A)   Microarrays enable scientists to determine the activity of thousands of genes at once.
B)   Microarrays use tiny portions of double-stranded RNA fragments from a large number of genes.
C)   Microarrays are used to determine which genes are active in different tissues or in tissues of different states of health.
D)   Microarrays use fluorescently labeled cDNA molecules to identify particular genes expressed at a particular time.

Question 9

Mutations in the proto-oncogene ras and the tumor-suppressor gene p53

Accepted Answer

A)   increase protein synthesis by the cell.
B)   can improve the chance of avoiding cancer as one ages.
C)   can enhance further mutations, which can develop into cancer.
D)   disrupt normal regulation of the cell cycle.

Question 10

A signal outside a cell triggers changes in the transcription and translation inside the cell through

Accepted Answer

A)   post-translational editing.
B)   signal transduction pathways.
C)   protein breakdown. B

Question 11

A cell has a mutation in both alleles of its p53 gene that causes the p53 protein to be three times as effective as normal. What do you predict would happen to this cell?

Accepted Answer

A)   The cell would divide three times as fast and would lead to cancer.
B)   The cell would divide into six daughter cells instead of two and would lead to cancer.
C)   The cell would divide with mutated DNA and would lead to cancer.
D)   The cell would divide normally or possibly not at all.

Question 12

The Pax6 gene codes for a transcription factor that initiates differentiation of cells that ultimately form the eye. Suppose that a researcher added an activator for the Pax6 gene to embryonic cells that are in the process of forming legs in Drosophila. What do you think the researcher will observe?

Accepted Answer

A)   Legs and eyes will develop normally.
B)   Legs will develop where the eyes normally develop.
C)   Eyes will develop where the legs normally develop.

Question 13

Which is not a factor that contributes to normal cells becoming cancerous?

Accepted Answer

A)   the conversion of a proto-oncogene to an oncogene
B)   mutations in a tumor-suppressor gene
C)   the production of more effective tumor-suppressor gene products
D)   excessive replication of proto-oncogenes

Question 14

There is a mutation in the operator of the trp operon in a cell such that the trp repressor is unable to bind to the operator. If tryptophan is added to the cell, what will happen?

Accepted Answer

A)   Tryptophan will bind to the repressor, and trp enzymes will be produced.
B)   Tryptophan will bind to the repressor, and trp enzymes will not be produced.
C)   Tryptophan will not bind to the repressor, and trp enzymes will be produced.
D)   Tryptophan will bind to the operator, and trp enzymes will be produced.

Question 15

E. coli can synthesize the amino acid threonine or absorb it from the environment. In the thr operon, the repressor is active when it is bound to threonine. If an E. coli bacterium is in an environment where threonine is absent, will transcription of threonine synthesis genes take place? Why or why not?

Accepted Answer

A)   yes, because threonine will not be bound to the repressor, so the repressor will be inactive
B)   no, because threonine will not be bound to the repressor, so the repressor will be inactive
C)   yes, because threonine will not be bound to the repressor, so the repressor will be active
D)   no, because threonine will not be bound to the repressor, so the repressor will be active A

Question 16

Which mammal has not yet been cloned and brought through the complete gestation cycle?

Accepted Answer

A)   cow
B)   human
C)   pig
D)   cat

Question 17

The figure below shows a normal cell transduction pathway. If the receptor weren't there, which of the following is the most likely outcome?

Accepted Answer

A)   Cell division will occur normally.
B)   Cell division will not occur at all.
C)   Cell division will be increased.
D)   Cell division will be decreased.

Question 18

Why can some plants be cloned from a single cell?

Accepted Answer

A)   Plant cells do not differentiate even when mature, so any cell can grow into an entire plant.
B)   Plant cells can dedifferentiate and give rise to all of the specialized cells required to produce an entire plant.
C)   Plant cells can produce genes to replace those lost during development.
D)   Plant cells are capable of self-renewal by utilizing cellular components from adjacent cells. B

Question 19

A single cell, the zygote, can develop into an entirely new organism with many different specialized cells. Which of the following statements about this process is false?

Accepted Answer

A)   Additional genetic information for the formation of specialized cells is passed on to the developing embryo via the mother.
B)   The descendant cells specialize by a process known as differentiation.
C)   The zygote contains all of the genetic information required for the development of many different cell types.
D)   Differentiation of the zygote into a multicellular organism results from selective gene expression.

Question 20

Which possible use of reproductive cloning is still considered by most to be an unresolved ethical issue?

Accepted Answer

A)   the production of genetically identical animals for experimentation
B)   cloning mammals for the production of potentially valuable drugs
C)   the production of organs in cloned pigs for transplant into humans
D)   the reproductive cloning of humans

Exam 11: How Genes Are Controlled

In thinking about their role in cell division, oncogenes are like the of a car, while tumor-suppressor genes are like the of a car.

Correct Answer
verified

RNA splicing involves the

Correct Answer
verified

A gene operon consists of

Correct Answer
verified

Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Mutations in the p53 gene can lead to cancer by

Correct Answer
verified

Which statement about microarrays is false?

Correct Answer
verified

Mutations in the proto-oncogene ras and the tumor-suppressor gene p53

Correct Answer
verified

A signal outside a cell triggers changes in the transcription and translation inside the cell through

Correct Answer
verified
B

A cell has a mutation in both alleles of its p53 gene that causes the p53 protein to be three times as effective as normal. What do you predict would happen to this cell?

Correct Answer
verified

The Pax6 gene codes for a transcription factor that initiates differentiation of cells that ultimately form the eye. Suppose that a researcher added an activator for the Pax6 gene to embryonic cells that are in the process of forming legs in Drosophila. What do you think the researcher will observe?

Correct Answer
verified

Which is not a factor that contributes to normal cells becoming cancerous?

Correct Answer
verified

There is a mutation in the operator of the trp operon in a cell such that the trp repressor is unable to bind to the operator. If tryptophan is added to the cell, what will happen?

Correct Answer
verified

Correct Answer
verified
A

Which mammal has not yet been cloned and brought through the complete gestation cycle?

Correct Answer
verified

The figure below shows a normal cell transduction pathway. If the receptor weren't there, which of the following is the most likely outcome?

Correct Answer
verified

Why can some plants be cloned from a single cell?

Correct Answer
verified
B

A single cell, the zygote, can develop into an entirely new organism with many different specialized cells. Which of the following statements about this process is false?

Correct Answer
verified

Which possible use of reproductive cloning is still considered by most to be an unresolved ethical issue?

Correct Answer
verified

Exam 11: How Genes Are Controlled

In thinking about their role in cell division, oncogenes are like the ________ of a car, while tumor-suppressor genes are like the ________ of a car.

Correct AnswerverifiedShow Answer

RNA splicing involves the

Correct AnswerverifiedShow Answer

A gene operon consists of

Correct AnswerverifiedShow Answer

Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Mutations in the p53 gene can lead to cancer by

Correct AnswerverifiedShow Answer

Which statement about microarrays is false?

Correct AnswerverifiedShow Answer

Mutations in the proto-oncogene ras and the tumor-suppressor gene p53

Correct AnswerverifiedShow Answer

A signal outside a cell triggers changes in the transcription and translation inside the cell through

Correct AnswerverifiedB

A cell has a mutation in both alleles of its p53 gene that causes the p53 protein to be three times as effective as normal. What do you predict would happen to this cell?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which is not a factor that contributes to normal cells becoming cancerous?

Correct AnswerverifiedShow Answer

There is a mutation in the operator of the trp operon in a cell such that the trp repressor is unable to bind to the operator. If tryptophan is added to the cell, what will happen?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

Which mammal has not yet been cloned and brought through the complete gestation cycle?

Correct AnswerverifiedShow Answer

The figure below shows a normal cell transduction pathway. If the receptor weren't there, which of the following is the most likely outcome?

Correct AnswerverifiedShow Answer

Why can some plants be cloned from a single cell?

Correct AnswerverifiedB

A single cell, the zygote, can develop into an entirely new organism with many different specialized cells. Which of the following statements about this process is false?

Correct AnswerverifiedShow Answer

Which possible use of reproductive cloning is still considered by most to be an unresolved ethical issue?

Correct AnswerverifiedShow Answer

In thinking about their role in cell division, oncogenes are like the of a car, while tumor-suppressor genes are like the of a car.

Correct Answer
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Correct Answer
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Correct Answer
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B

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A

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B

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