Deck 11: How Genes Are Controlled

Question 1

What is the first level of control of eukaryotic gene transcription?

A)RNA splicing
B)attachment of RNA polymerase to the promoter
C)DNA packing and unpacking
D)the binding and unbinding of transcription factors to enhancer sequences

Answer 1

C

Question 2

The "master control genes" that regulate other genes and determine what body parts will develop in which locations are called ________.

A)enhancers
B)homeotic genes
C)oncogenes
D)operons

Answer 2

B

Question 3

Which of these is a type of posttranscriptional regulation of gene expression?

A)inactivation of tRNA
B)alteration of DNA nucleotide sequences
C)breakdown of proteins
D)binding of transcription factors to enhancers

Answer 3

C

Question 4

In bacteria,what name is given to a cluster of genes with related functions,along with their DNA control sequences?

A)operon
B)operator
C)promoter
D)exon

Question 5

In a eukaryotic cell an abnormal protein is binding to the promoter for a gene.Which of the following processes will likely occur in this scenario?

A)Transcription factors will bind to enhancers.
B)Transcription factors will bind to the promoter.
C)The gene will be expressed normally.
D)RNA polymerase will bind to the promoter.

Question 6

Which of these plays a role in the regulation of transcription in both prokaryotic and eukaryotic cells?

A)RNA splicing
B)attachment of RNA polymerase to the promoter
C)transcription factors
D)gene operons

Question 7

Bacterial RNA polymerase binds to the ________.

A)operator
B)proto-oncogene
C)regulatory gene
D)promoter

Question 8

The process by which genotype becomes expressed as phenotype is ________.

A)gene regulation
B)transcription
C)gene expression
D)translation

Question 9

In prokaryotes,the production of a single RNA transcript for a group of related genes is under the control of ________.

A)an operon
B)enhancers
C)a signal transduction pathway
D)transcription factors

Question 10

Introns are ________.

A)noncoding DNA sequences
B)DNA sequences to which activators bind
C)expressed DNA sequences
D)the product of RNA splicing

Question 11

Repressors act by blocking the binding of ________ to the operator.

A)promoters
B)DNA polymerase
C)the operon
D)RNA polymerase

Question 12

Male tortoiseshell cats ________.

A)do not have an X chromosome
B)have orange and black patches of fur that reflect the pattern of X chromosome inactivation
C)are usually XYY individuals
D)are likely to be exceedingly rare and very likely to be sterile since normal male cats are XY

Question 13

In an operon,the ________ acts as an on/off switch.

A)operator
B)promoter
C)activator
D)repressor

Question 14

What would enable a single RNA transcript to be translated into different polypeptides?

A)The RNA transcript can be spliced more than one way.
B)The coded polypeptide may be modified in more than one way.
C)The length of the RNA transcript tail can vary.
D)Two different genes can produce the same RNA transcript,which will then be translated differently.

Question 15

What happened when researchers added BPDE,a component of tobacco smoke,to human lung cells in a laboratory experiment?

A)The cells behaved normally.
B)The cells shrank in size.
C)The cells developed mutations in their p53 genes.
D)The cells required less energy to grow.

Question 16

Cells communicate with one another via ________.

A)cascades of gene activation
B)the diffusion of RNA transcripts through adhesion junctions
C)signal transduction pathways
D)RNA splicing

Question 17

In eukaryotic cells,repressor proteins inhibit transcription by binding to ________.

A)silencers
B)enhancers
C)promoters
D)operons

Question 18

What would you assume if you found RNA transcripts of lactose-utilizing genes within E.coli?

A)Lactose has bound to the lac operon activator.
B)Lactose is present in the cell.
C)The lac operon activator protein is present in the cell.
D)The lac operon repressor protein is absent in the cell.

Question 19

Which of the following turns off transcription by binding to the operator?

A)RNA polymerase
B)repressor
C)promoter
D)lactose

Question 20

While examining a human cell that functions normally,you determine that it has 45 functional chromosomes and one chromosome that is almost completely inactive.You immediately decide that it is very likely that this cell ________.

A)came from a normal human female
B)is lacking a chromosome
C)is a gamete
D)will become cancerous if one or two more genes are mutated

Question 21

Which of these techniques could tell you how gene expression differs between individuals with and without cystic fibrosis?

A)therapeutic cloning
B)DNA microarray
C)reproductive cloning
D)karyotyping

Question 22

If you were working for a pharmaceutical company trying to develop anticancer drugs,what biological process would be the best target to investigate?

A)meiosis
B)mitosis
C)cellular respiration
D)glycolysis

Question 23

Which of the following is NOT a possible use of reproductive cloning?

A)the production of genetically identical mice and rats for experimentation
B)the production of organs in large farm animals for transplant into humans
C)restocking populations of extinct animals such as the wooly mammoth
D)creating stocks of stem cells for human therapeutic use

Question 24

When referring to cell division,oncogenes are most like ________ while tumor suppressor genes are most like ________.

A)the brakes on a car… the gas pedal on a car
B)the gas pedal on a car… the brakes on a car
C)the steering wheel on a car… the gas pedal on a car
D)the brakes on a car… the steering wheel on a car

Question 25

Many proto-oncogenes regulate ________.

A)cell growth
B)cell cloning
C)cell division
D)cell repair

Question 26

Data suggest that the normal version of BRCA1 functions as a(n)________.

A)oncogene
B)tumor-suppressor gene
C)proto-oncogene
D)silencer

Question 27

Why can mature plants be cloned to produce genetically identical copies?

A)Mature plant cells contain only a fraction of the genes found in an adult plant.
B)Plants have evolved over time to suit the need of human agriculture.
C)Mature plant cells can develop into all the specialized cells of an adult plant.
D)Scientists have engineered all plants to have this ability.

Question 28

Which of these is most likely to cause the development of a six-legged frog?

A)mutation of homeotic genes
B)binding of repressors to operons
C)a mutation in DNA polymerase that affects all cells
D)conversion of a proto-oncogene to an oncogene

Question 29

Inheritance of certain genes increases the risk of getting certain cancers; thus,it can be said that ________.

A)these cancers are inherited as a dominant trait
B)mutations that occur in somatic cells can be passed from parent to offspring
C)predisposition to these cancers is inherited
D)lifestyle will have little impact on cancer risk for these individuals

Question 30

Homeotic genes ________.

A)have very different sequences in plant cells as compared to animal cells
B)are an example of convergent evolution
C)are evidence of the common ancestry of eukaryotic organisms
D)regulate gene expression in both prokaryotic and eukaryotic cells

Question 31

More people die of ________ cancer than of any other cancer.

A)lung
B)skin
C)pancreatic
D)breast

Question 32

The figure below illustrates ________.

A)transcription factors
B)activators
C)alternative RNA splicing
D)protein activation

Question 33

What is a difference between embryonic and adult stem cells?

A)The use of embryonic stem cells raises fewer ethical issues than the use of adult stem cells.
B)Embryonic stem cells are undifferentiated; adult stem cells are partially differentiated.
C)It is easier to obtain embryonic stem cells.
D)Adult stem cells are easier to grow in culture.

Question 34

Which of these lifestyle choices will increase cancer risk?

A)jogging
B)spending less time in the sun
C)a diet low in plant fiber
D)quitting smoking

Question 35

________ is(are)responsible for more cancers than any other carcinogen.

A)Asbestos
B)UV radiation
C)Tobacco
D)X-rays

Question 36

Which risk factor is associated with cancer of the colon and rectum?

A)tobacco
B)viruses
C)UV radiation
D)dietary fat

Question 37

Which of the following is NOT an example of how tumors evolve?

A)Tumor cells can spread throughout the body.
B)Tumor cells show genetic variability.
C)Tumor cells grow uncontrollably.
D)Tumor cells pass on mutations when they divide.

Question 38

Examine the figure below.The initiation of transcription requires that enhancers bind to ________.

A)DNA
B)the promoter
C)transcription factors
D)RNA polymerase

Question 39

How is it that the cells in different body tissues are able to perform different functions?

A)The cells exhibit different patterns of gene expression.
B)Different chromosomes have been inactivated in different cells.
C)The cells contain different genes.
D)The mutations that have accumulated in the cells of the different tissues control functions.

Question 40

What name is given to a gene that causes cancer?

A)repressor
B)promoter
C)homeotic gene
D)oncogene

Question 41

What would be the best experiment to do next to determine if complete hexokinase gene expression is temperature dependent?

A)Measure the amount of hexokinase mRNA in cells at different temperatures.
B)Measure the rate of transcription of the hexokinase gene in cells at different temperatures.
C)Measure the amount of mRNA that is broken down in cells at different temperatures.
D)Measure the amount of hexokinase protein in cells at different temperatures.

Question 42

Examine the figure below.In a typical colon cancer,the first step is ________.

A)the inactivation of a tumor-suppressor gene
B)the mutation of a tumor-suppressor gene,producing an oncogene
C)the mutation of a proto-oncogene,producing an oncogene
D)the conversion of an oncogene to a tumor-suppressor gene

Question 43

Consider the following figure,which outlines cloning by nuclear transplantation.Why does the clone NOT resemble the surrogate mother?

A)The sperm came from a male donor,who would also pass some of his traits to the clone.
B)The embryonic cells are adversely influenced by the surrogate.
C)The DNA for the clone comes from the genetic donor,not the surrogate.
D)The nuclear material from the egg would influence the appearance of the clone.

Question 44

What can you conclude from these results?

A)Unpacking of the hexokinase gene occurs only at 37°C.
B)Transcription of the hexokinase gene occurs less frequently at lower temperatures.
C)The levels of hexokinase protein are not affected by temperature.
D)Translation of the hexokinase gene occurs more frequently at higher temperatures.

Question 45

Jim learned that some cancer cells produce more growth-stimulating proteins than others.What would you give him as a plausible explanation?

A)Tumor suppressor genes may have been activated in these cells.
B)Proto-oncogenes may have mutated to become oncogenes in these cells.
C)Mutations in homeotic genes may be responsible.
D)This may result from vitamin C and vitamin E deficiencies.

Question 46

DNA microarrays can be used to determine relative levels of gene expression between samples.DNA microarrays are usually interpreted by color: green means higher mRNA levels,yellow means equal levels,and red means lower levels.If you ran the samples from the temperature experiment on a DNA microarray using the 25°C experiment as a baseline,what results do you predict you would obtain?

A)The samples from the 37°C experiment would be green and the samples from the 10°C would be red.
B)The samples from the 37°C experiment would be red and the samples from the 10°C would be green.
C)The samples from the 37°C experiment would be green and the samples from the 10°C would be yellow.
D)The samples from the 37°C experiment would be yellow and the samples from the 10°C would be red.

Question 47

Jim learned that viruses can sometimes cause cancer and wants to know why.You tell him that ________.

A)a human cell can acquire a tumor-suppressor gene from a virus
B)a human cell can acquire a proto-oncogene from a virus
C)a human cell can acquire an oncogene from a virus
D)some viruses are passed from mother to child and cause "inherited" cancers

Question 48

The lac operon is shown in the accompanying figure.Answer the following question after reviewing the figure.The lac operon is usually in the ________ position and is activated by ________.

A)on...the repressor
B)off...lactose
C)off...the repressor
D)on...the promoter

Question 49

Jim came across an advertisement for an herbal supplement that claimed to cure lung cancer by targeting precancerous cells in the lungs.If this claim were true,which of the following is a possible mechanism by which it may act?

A)The supplement would increase mutation rates in proto-oncogenes.
B)The supplement would inhibit the production of tumor suppressor proteins.
C)The supplement would stimulate translation of growth factors
D)The supplement would restrict the transcription of oncogenes.