Chapter 10: Control of Gene Expression
Study Guide
1. Approximately what percentage of a cell's genes is being used at any one time:
A. 90 percent
B. 50 percent
C. 70 percent
D. 10 percent
2. Binding of _____ to _____ in DNA can increase the rate of transcription of specific
genes:
A. Enhancers; operators
B. Activators; enhancers
C. Repressors; promoters
D. Repressors; operators
E. Enhancers; promoters
3. What happens to a male's reproductive organ development when the SRY gene is
mutated and not expressed:
A. Portions of both the male and female reproductive organs will develop
B. The reproductive organs will remain immature
C. Male reproductive organs, included testes, will develop but testosterone will
not be produced
D. Male reproductive organs will develop normally
E. Female reproductive organs will develop
4. What is a type of master gene that controls the formation of body parts during
development:
A. Control gene
B. Developmental gene
C. Differentiation gene
D. Homeotic gene
E. Gradiant gene
5. This prevents translation until the mRNA has reached its final destination:
A. Cap on an mRNA “zip code” sequence:
B. microRNAs
C. Poly-A-tail
D. Double-stranded RNA
6. Muscle cells differ from bone cells because:
A. They carry different genes
B. They use different genes
C. Both A and B
7. Regions of chromatin can be loosened to increase access to DNA through this
chemical modification of histone proteins:
A. Promotion
B. Dehydration
C. Acetylation
D. Methylation
8. What happens to the lac operon when lactose is present:
A. Transcription is initiated because a lactose derivative directly binds to the lac
operon
B. Transcription is repressed because a lactose derivative inhibits RNA
polymerase activity
C. Transcription is repressed because a lactose derivative causes the lac operon to
twist
D. Transcription is initiated because a lactose derivative removes the lac
operon repressor
9. You are looking at a mixture of cells on a slide from different people. You are able to
make the Barr bodies turn red using a special technique. You count 20 cells on the
slide and 6 of them have the red Barr bodies. How many total male cells are there on
the slide:
A. 20
B. 6
C. 13
D. 14
10. Pattern formation during embryonic development is based on:
A. RNA interference
B. Post-transcriptional modification
C. Maternal mRNA gradient in the embryo
D. A promoter and one or more operators
E. Dosage compensation
11. The expression of a gene may depend on:
A. The type of organism
B. Environmental conditions
C. The type of cell
D. All of the above
12. What DNA site can increase the transcription rate of a gene that may be thousands of
base pairs away:
A. Silencer
B. Activator
C. Transcription increaser
D. Enhancer
E. Transcription factor
13. One function of a transcription factor that acts as an activator is to:
A. Block the activity of DNA degrading enzymes
B. Assemble the DNA promoter sequences
C. Recruit RNA polymerase to a promoter
D. Inhibit the function of microRNAs
E. Prevent DNA polymerase from binding to a promoter
14. How does chromatin structure affect transcription:
A. The methylation of histone proteins promotes transcription
B. The acetylation of histone proteins represses transcription
C. DNA regions that are unwound from histones are not accessible to RNA
polymerase
D. DNA regions that are unwound from histones are accessible to RNA
polymerase
E. DNA regions that are unwound from histones are not accessible to DNA
polymerase
15. When a promoter is methylated, gene expression is:
A. Silenced
B. Enhanced
C. Activated
D. Maintained
16. Methylation of DNA can occur in response to:
A. Environmental challenges
B. Replicational mutaions
C. Homeotic genes expression
D. Master gene expression
17. The obvious advantage of the lactose operon system is that:
A. The bacteria will make lactose only in the presence of the proper enzymes
B. Lactose is not needed as energy for bacteria
C. Milk is not needed for the adult human diet
D. Glucose can substitute for lactose in the diet of intolerant persons
E. Lactose-metabolizing enzymes need not be made when lactose is not
present
18. In the prokaryotic lac operon system, what cannot bind to the DNA if lactose is not
present:
A. DNA polymerase
B. RNA polymerase
C. Repressor
D. Operator
19. In a prokaryotic operon, the region to which RNA polymerase binds is called:
A. The operator sequence
B. The heterogeneous nuclear DNA
C. Al enhancer gene
D. The repressor gene
E. The promoter sequence
20. What is the master gene for male sex determination in mammals:
A. BRCA1
B. PAX6
C. XIST
D. ABC
E. SRY
21. In terms of sex chromosomes, females have:
A. One X chromosome and one Y chromosome
B. Two active X chromosomes
C. One X chromosome
D. Two Barr bodies
E. One X chromosomes and one Barr body
22. Homeotic genes code for:
A. Enzymes
B. Translation enhancers
C. Enzymes
D. Transcription factors
23. A gene that is knocked out is:
A. Deleted
B. Inactivated
C. Expressed
D. Either A or B
24. Experiments that utilize the deletion of a gene are referred to as ____ experiments:
A. Contol
B. Deletion
C. Knockout
D. Ablation
E. Tinman
25. The process by which a less specialized cell becomes more specialized; for example a
stem cell becoming a muscle cell:
A. Specialization
B. Expression
C. Differentiation
D. Translation
26. Four of the five answers listed below are types of gene control in eukaryotes. Select
the exception:
A. Replicational control
B. Transcriptional control
C. Post-transcriptional control
D. Transcript processing control
E. Translational control
27. Proteins that influence RNA synthesis by binding directly to DNA are called:
A. Promoters
B. Transcription factors
C. Operators
D. Enhancers
28. Lactose intolerance is a condition in humans characterized by:
A. Failure to turn on the mammalian lac operon
B. A mutation in the lactose-metabolizing enzyme
C. Excess levels of the lactose-metabolizing enzyme
D. Intestinal E. coli turning on their lac operons
E. The absence of the lactose-metabolizing enzyme
29. In the prokaryotic lac operon system, when lactose is not present the repressor binds
to the:
A. Operators
B. Operon
C. Promoter
D. Gene
E. Enhancer
30. In prokaryotes, a group of genes together with a promoter-operator DNA sequences
that controls their transcription is:
A. Operon
B. Homeotic gene
C. Master gene
D. Operator
31. In eukaryotes, the binding of _____ to _____ in DNA can decrease the rate of
transcription of specific genes:
A. Enhancers; operators
B. Activators; enhancers
C. Repressors; promoters
D. Repressors; operators
E. Enhancers; promoters
32. Which epigenetic modification can be passed down to progeny:
A. DNA acetylation
B. Histone acetylation
C. Histone oxidation
D. DNA methylation
E. Histone methylation
33. A random inactivation of maternal and paternal X chromosomes in cells is referred to
as:
A. XIST
B. Barr body
C. Mosaic
D. SRY
34. In prokaryotes the binding of _____ to _____ in DNA can decrease the rate of
transcription of specific genes:
A. Enhancers; operators
B. Activators; enhancers
C. Repressors; promoters
D. Repressors; operators
E. Enhancers; promoters
35. Regions of chromatin can be condensed to restrict access to DNA through this
chemical modification of histone proteins:
A. Promotion
B. Dehydration
C. Acetylation
D. Methylation
36. Bacteria control gene expression mainly by:
A. Regulating mRNA transport
B. Controlling translational machinery
C. Adjusting the rate of transcription
D. Post-translational modification
E. Chemically modify histones
37. How does the X chrmomose gne XIST facilitate X chromosome inactivation:
A. The XIST protein product coats one X chromosome, preventing formation of a
Barr body
B. The XIST DNA coats one X chromosome. causing formation of a Barr body
C. The XIST protein product coats one X chromosome, causing formation of a
Barr body
D. The XIST RNA product coats one X chromosome, causing formation of a
Barr body
E. The XIST RNA product coats one X chromosome, preventing formation of a
Barr body
38. The stability of mRNA is affected by:
A. Bound proteins and microRNAs
B. Length of its poly-A-tail and bound proteins
C. Bound proteins and 5’ cap
D. Length of its poly-A-tail and 5’ cap
39. The mechanism in which X chromosome inactivation equalizes expression between
males and females is known as:
A. Sex trait adaptation
B. Dosage compensation
C. Quantity equivalence
D. Chromosomal uniformity
E. Gender equalization
40. Homeotic genes produce transcription factors that contain ___ which bind to
promoters, turning a set of genes ___:
A. Knockout regions; off
B. Knockout regions; on
C. Homeodomain; off
D. Homeodomain; on
41. Expression of a microRNA complementary in sequence to a gene _____ that gene:
A. Speeds transcription of
B. Methylates the bases in
C. Blocks transcription of
D. Inhibits translation of
E. Replicates
42. In eukaryotes these short strands of complementary RNA bind mRNAs and prevent
their translation:
A. Homeodomians
B. microRNAs
C. Master genes
D. Transcription factors