Deck 12: Regulation of Gene Activity

Question 1

What is the role of transcription factors?

A)binding heterochromatin to prevent transcription
B)binding promoter of a gene to start translation
C)binding promoter to start transcription
D)binding operator to prevent transcription
E)binding repressor to prevent transcription

Answer 1

C
Explanation: Transcription factors are proteins that assist the binding of RNA polymerase to a promoter of genes,to start transcription of that gene.

Question 2

Which of the following structures is visible during cell division?

A)heterochromatin
B)chromosomes
C)nucleosomes
D)chromatin
E)histones

Answer 2

B
Explanation: Chromatin is condensed to form chromosomes that are visible during cell division.

Question 3

Which component in an operon acts first in expression?

A)structural genes - mRNA transcription
B)promoter - where RNA polymerase first binds to DNA
C)terminator - last part of a gene
D)regulatory gene - codes for the repressor protein
E)operator - if unbound,allows RNA polymerase to bind DNA

Answer 3

E
Explanation: A promoter is a short sequence of DNA where RNA polymerase first attaches when genes are to be transcribed.The regulatory gene codes for a DNA-binding protein that acts as a repressor.An operator is a short portion of DNA where an active repressor binds.When an active repressor is bound to the operator,RNA polymerase cannot attach to the promoter,Structural genes are transcribed as a unit.

Question 4

Where on the DNA do transcription activator proteins bind?

A)enhancers
B)regulatory genes
C)operators
D)promoters
E)repressors

Question 5

Which statement would be correct for genes controlling development,excluding Hox genes?

A)The sequence is the same in many different organisms.
B)It controls whether the cell will have organelles.
C)It has been conserved as evolution has occurred.
D)The homeobox encodes for a homeodomain.
E)It encodes for DNA binding part of a transcription factor.

Question 6

What are the highly condensed portions of chromatin which appear as very dark areas in an transmission electron micrograph?

A)histone
B)DNA helix
C)heterochromatin
D)nucleosome
E)euchromatin

Question 7

Which is the loosely condensed chromatin where genes are expressed?

A)nucleosomes
B)euchromatin
C)chromosome
D)heterochromatin
E)histones

Question 8

Which molecules regulate the process of transcription by binding genes and turning on their expression?

A)transcriptional factors
B)posttranslational control promoters
C)repressible control factors
D)translational factors
E)heterochromatin factors

Question 9

Figure:
This figure shows the levels of chromatin structure.What does "C" represent?

A)DNA helix
B)a nucleosome
C)compacted chromosome
D)coiled nucleosomes
E)histones

Question 10

Which of the following is a component of the operon model?

A)a transposon
B)a microfilament
C)a Barr body
D)a DNA synthase
E)an operon

Question 11

An inactive X chromosome which is found in females is referred to as

A)a Barr body
B)a histone.
C)a nucleosome.
D)a repressible chromosome
E)an inducible chromosome

Question 12

A biologist is studying a gene which is located outside the operon and codes for a repressor protein that can deactivate the operon.This biologist is studying which of the following genes?

A)structural gene
B)promoter gene
C)regulatory gene
D)homeotic gene
E)operator gene

Question 13

Which of the following structures can be transcribed to make mRNA?

A)compacted chromatin
B)DNA helix
C)nucleosome
D)histone
E)condensed chromosome

Question 14

The main purpose of eyespots in living organisms is

A)to help the animal sense dark
B)to help the animal see predators better
C)to confuse potential predators
D)to help the animal find prey
E)to help the animal sense light

Question 15

Genes which are involved in pattern formation and organization of body parts are referred to as:

A)Regulatory regions of structural genes
B)Master developmental regulatory genes
C)Heterochromatin regulatory genes
D)Developmental enhancer genes
E)Nucleosome regulatory genes

Question 16

Which of the following statements is true about the lac operon?

A)The lac operon is usually turned off in the presence of lactose.
B)The lac operon is usually turned on in the presence of any sugar.
C)The lac operon is usually turned on in the presence of glucose.
D)The lac operon is usually expressed continuously in the cell.
E)The lac operon is usually turned on in the presence of lactosE.

Question 17

Which developmental changes would have have been caused by genes other than Hox genes?

A)extra toes in foxes
B)extra fingers are fused together in humans
C)missing eyes in squid
D)short arms that are missing bones in mice
E)two pairs of wings in fruit flies

Question 18

Figure:
This figure shows the levels of chromatin structure.What does "A" represent?

A)a nucleosome
B)compacted chromosome
C)histones
D)DNA helix
E)coiled nucleosomes

Question 19

Figure:
This figure shows the levels of chromatin structure.What does "D" represent?

A)a nucleosome
B)looped chromatin
C)histones
D)compacted chromosome
E)DNA helix

Question 20

Since the same DNA and genes are found in each cell in the body,all the proteins made and in each cell of the body will be the same.

Question 21

If you were studying the control of gene expression which begins when processed mRNA reaches the cytoplasm and before there is a protein product,you would be studying

A)transcription control
B)posttranscriptional control
C)posttranslational control
D)translational control
E)inducible control

Question 22

Figure:
Which of the following occurs outside of the nucleus in eukaryotic cells?

A)chromatin packing
B)mRNA processing
C)transcriptional control
D)translational control
E)posttranscriptional control

Question 23

Figure:
This figure shows the levels at which control of gene expression occurs in eukaryotic cells.What does "B" represent?

A)posttranscriptional control
B)transcriptional control
C)posttranslational control
D)translational control
E)chromatin structure

Question 24

Cells from both the hypothalamus and thyroid gland contain the same calcitonin gene,but the calcitonin proteins made in the two tissues differ.What causes the variation in the protein forms?

A)pre-mRNA alternative splicing
B)DNA activation
C)mRNA activation
D)post-mRNA processing
E)small RNAs regulation

Question 25

Where in the cell do the translation repressor protein and the proteasome work?

A)on the nuclear membrane
B)within the ribosome
C)in the cytoplasm
D)on the plasma membrane
E)inside the nucleus

Question 26

What is the function of the translation repressor protein?

A)It binds to a gene on the DNA and prevents translation.
B)It binds to a master developmental regulatory gene and prevents translation.
C)It binds to amino acids and prevents them from forming the protein chain.
D)It binds to a proteasome and prevents translation.
E)It binds to a mRNA and prevents translation from that mRNA.

Question 27

Figure:
Which is the correct order of gene expression in eukaryotic cells?

A)transcription control,posttranscriptional control,translational control,posttranslational control,chromatin structure
B)posttranslational control,translational control,chromatin structure,transcription control,posttranscriptional control
C)translational control,posttranslational control,chromatin structure,transcription control,chromatin structure
D)chromatin structure,transcription control,posttranscriptional control,translational control,posttranslational control
E)transcription control,chromatin structure,posttranscriptional control,translational control,posttranslational control

Question 28

The control of gene expression which occurs in the nucleus and involves mRNA processing is referred to as:

A)Posttranscriptional control
B)Transcription activator control
C)Translational control
D)mRNA induction
E)Posttranslational control

Question 29

What molecules specifically join with an enzyme to form a RNA-induced silencing complex?

A)Hox mRNA
B)pre-mRNA
C)enhancer RNA
D)small interfering RNA
E)mature mRNA

Question 30

Which of the following would,if found,be a new discovery about stimulatory signal transduction pathways for the development of cancer?

A)activating factor
B)transcription factor
C)growth factor
D)oncogene
E)receptor

Question 31

Which genes code for proteins that stimulate the mitotic cell cycle?

A)proto-oncogenes
B)oncogenes
C)tumor suppressor genes
D)totipotent genes
E)inducible genes

Question 32

One gene has exons ABCDE.In nerve cells,the mRNA molecules from this gene contain the exons ABC.In muscle cells,the mRNA molecules from this contain BCE.What causes the difference between the mRNA molecules in different tissues?

A)DNA activation
B)DNA processing
C)mRNA posttranslational control
D)mRNA activation
E)pre-mRNA splicing

Question 33

What happens inside a normal cell when a inhibitory growth factor binds to its receptor of the cell membrane?

A)A transcription factor turns on mechanisms that causes a mutation in tumor suppressor gene.
B)A transcription factor turns on a proto-oncogene,which inactivates the cell cycle.
C)A transcription factor turns on a tumor suppressor gene,which activates the cell cycle.
D)A transcription factor turns on a tumor suppressor gene,which inactivates the cell cycle.
E)A transcription factor turns on a proto-oncogene,which activates the cell cyclE.

Question 34

Proteins with special tags enter the proteasome and are digested into peptide fragments by a protease.

Question 35

Which type of gene expression control occurs after the protein has been synthesized?

A)translational control
B)posttranslational control
C)inducible control
D)posttranscriptional control
E)transcription control

Question 36

Which are cancer-causing genes in mice and humans?

A)totipotent genes
B)proto-oncogenes
C)oncogenes
D)inducible genes
E)tumor suppressor genes

Question 37

Which genes inhibit the cell cycle and promote apoptosis?

A)oncogenes
B)inducible genes
C)totipotent genes
D)proto-oncogenes
E)tumor suppressor genes

Question 38

What happens inside a normal cell when a stimulatory growth factor binds to its receptor of the cell membrane?

A)A transcription factor turns on a proto-oncogene,which activates the cell cycle.
B)A transcription factor turns on a tumor suppressor gene,which inactivates the cell cycle.
C)A transcription factor turns on mechanisms that causes a mutation in tumor suppressor gene.
D)A transcription factor turns on a proto-oncogene,which inactivates the cell cycle.
E)A transcription factor turns on a tumor suppressor gene,which activates the cell cyclE.

Question 39

A newly discovered level of gene expression in vertebrates involves the DNA areas that used to be called "junk DNA".Actually these DNA are encoded into

A)small RNAs for RNA interference.
B)repressor RNAs for halting transcription.
C)enhancer RNAs for activating transcription.
D)Hox mRNAs for changing splicing.
E)operon RNAs for opening the double helix.

Question 40

When insulin is initially synthesized,the polypeptide chain is too long and must have a part cleaved off.What type of regulation of gene expression is this?

A)post-translational control
B)chromatin regulation
C)post-transcriptional control
D)transcriptional control
E)translational control

Question 41

The enzyme which copies DNA at the start of expression is DNA polymerase.

Question 42

What large molecule is usually wrapped around histones?

A)DNA
B)RNA
C)polyphenols
D)protein
E)lipids

Question 43

Regulatory genes are located outside the operons which they regulate.

Question 44

Alternative mRNA splicing can lead to more than one protein product being made from the information in one gene.

Question 45

What kind of access does RNA Polymerase have to heterochromatin?

A)none
B)moderate
C)easy
D)varied by chromosome
E)permanent

Question 46

Small RNA's have no effect on gene expression.

Question 47

If a scientist is studying the formation of new blood vessels within a tumor,he or she would be studying the process of

A)morphogenesis
B)blood vessel promotion
C)carcinogenesis
D)apoptosis
E)angiogenesis

Question 48

The development of a malignant tumor is referred to as carcinogenesis.

Question 49

Expression of the genes in the lac operon is turned on by the sugar glucose.

Question 50

The first step of cancer development is

A)cytoskeletal disorganization
B)cells growth on top of each other
C)loss their differentiation
D)release of growth factors to form new blood vessels
E)mutation in a gene related to cell cycle progression