Deck 15: Controls Over Genes

Question 1

Regulatory elements in gene control interact with

A)new polypeptide chains.
B)DNA.
C)RNA.
D)final proteins.
E)all of these.

Answer 1

E

Question 2

Which letter in the above figure represents breast cancer?

A)A rounded cells
B)B irregular shaped cells
C)both A and B
D)neither A or B
E)this is prostate tissue

Answer 2

B

Question 3

The polytene chromosomes of certain insect larvae churn out copious amounts of gene products because

A)they are acetylated.
B)they are methylated.
C)they contain numerous side-by-side copies of genes.
D)they have multiple promoter sites.
E)their histones are only loosely associated with the DNA molecules.

Answer 3

C

Question 4

A radical mastectomy involves the removal of

A)any breast tumor.
B)a benign breast tumor.
C)a malignant breast tumor.
D)a breast, all lymph nodes under the arm, and skeletal muscles in the chest wall under the breast.
E)both breasts.

Question 5

The rate at which mRNA is processed by ribosomes is an example of

A)transcriptional control.
B)transcript processing control.
C)transport control.
D)translational control.
E)post-translational control.

Question 6

Which of the following statements is (are) true concerning promoters?

A)They are short sequences in DNA.
B)They are locations in DNA where regulatory proteins gather.
C)They control transcription.
D)They are associated with specific genes.
E)All of these are true.

Question 7

Which of the following causes DNA to wrap tightly around histones essentially preventing transcription?

A)methylation
B)acetyl CoA
C)nitrogenation
D)dehydration
E)carbonation

Question 8

When cells stop responding to normal controls over growth and division they

A)begin to form a tumor.
B)produce a malignancy.
C)start to die.
D)kill surrounding cells.
E)produce scar tissue.

Question 9

Which of the following statements concerning cancer cells is most accurate?

A)Proto-oncogenes are part of the regulatory section of a chromosome.
B)Tumor cells have lost their ability to stop dividing.
C)Proto-oncogenes help control runaway cell division.
D)Benign tumor cells usually spread only to adjacent organs.
E)Metastasis is the spread of benign cells.

Question 10

Which of the following statements is false concerning breast cancer?

A)It develops in one of 10,000 females a year.
B)About 180,000 new cases are diagnosed a year in the United States.
C)It does not affect males.
D)It may have many underlying causes.
E)Gene mutations predispose individuals to developing certain kinds of breast cancer.

Question 11

When cancer cells infiltrate muscle cells under the breast, the only treatment option is

A)radiation therapy.
B)chemotherapy.
C)a radical mastectomy.
D)gene therapy.
E)diet modification with massive vitamin intake.

Question 12

The snipping out of specific introns is an example of what type of gene expression control?

A)transcriptional
B)transcript processing
C)transcript transport
D)translational
E)post translational

Question 13

Differentiation is the process by which cells

A)mature into larger cells.
B)change from one type of muscle to another.
C)allows cells to change to fix injuries.
D)turn on all the genomic genes.
E)become specialized by turning on some genes and turning off others.

Question 14

When, how, and to what extent any gene control mechanism comes into play depends on

A)the type of cell.
B)the cell's function.
C)the cell's chemical environment.
D)signals from the cells external environment.
E)all of these.

Question 15

Which of the following statements is false?

A)All the cells of a human have the same genes.
B)Only red blood cells have hemoglobin genes.
C)Different genes are activated depending on the cell they are in.
D)Liver cells and brain cells differ mostly in form and function, not in the genes they have.
E)Cells don't express all of their genes all of the time.

Question 16

BRCA1 and BRCA2

A)are called cancer genes.
B)code for tumor suppressing proteins.
C)are involved in DNA repair mechanisms.
D)in their mutated forms often occur in cancerous breast cells.
E)are all of these.

Question 17

The development of organisms is based on

A)which genes are active in a given cell.
B)when the genes function.
C)what gene products appear.
D)the amount of cellular products generated.
E)all of these.

Question 18

The activation of enzymes by the removal of a portion of polypeptide chain is an example of

A)transcriptional control.
B)transcript processing control.
C)transport control.
D)translational control.
E)post-translational control.

Question 19

Genes on newly synthesized DNA molecules can be blocked by the addition of __________ to the DNA.

A)-CH₃
B)-CH₃CO^-
C)-NH₂
D)-H₂O
E)any of these

Question 20

Cell differentiation accounts for cells of an organism becoming different in

A)composition.
B)structure.
C)function.
D)development.
E)all of these.

Question 21

In knockout experiments,

A)genes are removed from chromosomes.
B)normal genes are replaced physically by mutated genes.
C)wild type genes are mutated to prevent their transcription or translation.
D)mRNAs are prevented from attaching to ribosomes.
E)the protein products of specific genes are inactivated.

Question 22

Mutation of the B group gene in Arabidopsis thaliana affects development in its flower's

A)first whorl only.
B)second whorl only.
C)third whorl only.
D)first and second whorls.
E)second and third whorls.

Question 23

Which of the following statements is false concerning X chromosome inactivation?

A)It is an accident of evolution.
B)It is an example of dosage compensation.
C)It is a gene control mechanism.
D)Normal development of female embryos depends on it.
E)It does not occur in males.

Question 24

Homeotic genes

A)code for homeodomains.
B)code for regulatory proteins.
C)are a class of master genes.
D)affect transcription.
E)are all of these.

Question 25

The products of genes that are switched on in specific tissues at specific stages of development affect mainly

A)gene replication.
B)gene transcription.
C)mRNA transcript processing.
D)translation.
E)post-translational processing of proteins.

Question 26

In the ABC model of flower development in Arabidopsis thaliana, sepals form when gene(s) __________ is(are) switched on.

A)A
B)A and B
C)B and C
D)C
E)A and B and C

Question 27

Which of the following statements is(are) true of homeotic genes?

A)More than one hundred of them have been identified.
B)The same mechanisms control their transcription regardless of the species.
C)Many of them are functionally interchangeable among species.
D)They likely evolved in the most ancient eukaryotic cells.
E)All of these are true.

Question 28

For the calico coloration in cats, which of the following is NOT true?

A)Orange color is on one X chromosome.
B)Black color is on one X chromosome.
C)White is the result of another gene that blocks all pigment production.
D)The color white is found on the Y chromosome.
E)It does not occur in males.

Question 29

The eyeless gene of Drosophila

A)has counterparts in humans.
B)has counterparts in mice.
C)has counterparts in squids.
D)points to a shared ancestor among evolutionarily distant animals.
E)is all of these.

Question 30

In the ABC model of flower development in Arabidopsis thaliana, carpels form when gene(s) __________ is(are) switched on.

A)A
B)A and B
C)B and C
D)C
E)A and B and C

Question 31

In the ABC model of flower development in Arabidopsis thaliana, petals form when gene(s) __________ is(are) switched on.

A)A
B)A and B
C)B and C
D)C
E)A and B and C

Question 32

Mutation of the C group gene in Arabidopsis thaliana produces flowers that

A)are sterile.
B)have no carpels.
C)have no stamens.
D)have a profusion of petals.
E)are all of these.

Question 33

Homeotic genes generally control

A)X chromosome inactivation.
B)formation of specific body parts
C)hormone synthesis.
D)dosage compensation.
E)none of these.

Question 34

A mammalian female's

A)cells usually have multiple Barr bodies.
B)body is a mosaic for the X-linked traits she inherits.
C)Barr bodies are active in some cells.
D)Barr bodies are produced after puberty.
E)X-linked recessive genes are always expressed because of the deactivation of an X chromosome in each cell.

Question 35

In the ABC model of flower development in Arabidopsis thaliana, stamens form when gene(s) __________ is(are) switched on

A)A
B)A and B
C)B and C
D)C
E)A and B and C

Question 36

Mutation of the A group gene in Arabidopsis thaliana affects development in its flower's

A)first whorl only.
B)second whorl only.
C)third whorl only.
D)first and second whorls.
E)second and third whorls.

Question 37

The color distribution in the fur of calico cats results from

A)hybridization.
B)a specific nutritional deficiency.
C)a genetic defect.
D)X chromosome inactivation.
E)selective breeding.

Question 38

In females with incontinentia pigmenti, the mosaic effect of X inactivation in human females can be observed in

A)skin color.
B)hair color.
C)distribution of fat cells.
D)distribution of sweat glands.
E)all of these.

Question 39

X chromosome inactivation results in the

A)total inactivation of both X chromosomes.
B)inactivation of only the paternal X chromosome.
C)inactivation of only the maternal X chromosome.
D)inactivation of either the paternal X chromosome or the maternal X chromosome.
E)nonrandom inactivation of X chromosomes in the initial cells of tissues.

Question 40

Researchers tend to name genes based on what happens in their absence.The tinman gene in Drosophila results in flies

A)without hearts.
B)with nonjointed legs.
C)with a thick exoskeleton.
D)with rust colored eyes.
E)without brains.

Question 41

Repressor proteins

A)prevent binding of RNA polymerase to DNA.
B)cause the DNA regions that contain the operator to twist or loop.
C)inactivate operon genes when their products are not required.
D)bind to sets of operators.
E)do all of these.

Question 42

Genes located in cells in different regions of the body during embryonic development may

A)be turned on and off.
B)never be turned on.
C)be turned on and left on.
D)be activated for only a short time in one cell and a long time in another cell.
E)do all of these.

Question 43

As a result of the action illustrated in the figure,

A)structural genes are transcribed.
B)lactose is broken down.
C)the lactose operon is repressed.
D)the regulatory gene is inactivated.
E)lactose production is enhanced.

Question 44

The prokaryote operon model explains gene regulation at the level of

A)replication.
B)transcription.
C)transcript processing.
D)transcript transport.
E)translation.

Question 45

In prokaryotes, most of the control of gene expression is at the __________ level.

A)transcriptional
B)transcript processing
C)transport
D)translational
E)post-translational

Question 46

The obvious advantage of the lactose operon is that

A)it allows bacteria to survive in the presence of lactose.
B)lactose-metabolizing enzymes need not be made when lactose is not present.
C)it enables bacteria to make lactose only in the presence of the proper enzymes.
D)it negates the need for milk in the diet of adult humans.
E)it enables glucose to substitute for lactose in the diet of lactose intolerant persons.

Question 47

Which statement is false concerning the lactose operon?

A)It contains a set of operators.
B)It contains three structural genes that manufacture lactose-metabolizing enzymes.
C)It contains a single promoter.
D)It contains a single operator.
E)The promoter lies between two operators.