the question.

- -!Cqtosine

makes up38/" of the nucleotides in a sample of DNA from an organism. What percent of thet- " nucleotides in this sample will be thymine?

@'zB\2qc) 31D) 38E) It cannot be determined from the information provided.

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

Use Figure 16.1 to answer the following questions.

I+N DNA

lap - lsphybr id DNA

lsN DNA

Figure L6.1

-ZYA space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it

is a carbon-based life form that has DNA. You grow the cells in 15N medium for several generations andthen transfer it to 14N medium. Which pattern in Figure 16.1 would you expect if the DNA was replicateclin a conservative manner?

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

--af,Which enzymes catalyze the elongation of a DNA strand in the 5'* 3' direction?A) primase

!) Orua Hgase

I DNA polymerasesD) topoisomeraseE) helicase

-Lflilhich

of the following isleast related to the others in the list?

/\ A) Okazaki fragments/ I

-B) replication fork

'r (ptelomeraseD) DNA polymerasesE) semiconservative

\=

|tqlU

E.B

D.

1=_\

).--r(lFocoe1|

U\

/7-\

)r-rf

]t tli l t li l t l-'u

A.

--{Xnew DNA strand only elongates in the 5' to 3' direction because

A) DNA ;;;;;;'" begins Jai"g nucleotides ui,1h" 5' end''uiol"'"'ot

i'ag*e"t' p-'uvent eloigation in the 3' to 5'direction'

I C) the polarity of the ONa *"i"."f"" prevents addition of nucleotides at the 3' end'

f I t"iti*tton must Progress toward the replication fork'

Ll IE)DNA;;;;;;;Jadis nucleotides onlv to the free 3'end'\-'

*rryr"problem of replicating the lagging strand of DNA-that is, adding bases in the 3' - 5' direction-

requires which of the following?

eiPNe l igase

I - B)RNA Primersf- ciotutiti fragments

I -

P{A and B onlY'- f€)'R,8, and C

n Anuis the primer that is required to initiate the synthesis of a new DNA strand?

AIr f inNaB)DN;c)p' l i " i "D) l igaseE)pr imaseI '

, *r Inut is the rore of DNA ligase in the elongation of the lagging strand during DNA reptication?

^

"' oj'tv"1n*tze RNA nucleotides to make a primer

B) catalyze the lengthening of telomeres

ft6ioi" i)kazaki fragments together

@."t*ma the Parental double helix

Vstabilize the unwound parental DNA

-.9fWtrirt ' 'ofthefol lowinghelptoholdtheDNAstrandsaPartwhiletheyarebeingreplicated?

nt /v

-.wr

At \

A) helicaseB) IigaseC-) DNA PolYmerasefi) single-stranded binding proteins

Y) exonuclease

In DNA, the designations 3' and 5' refer to the

6)carbon atoms.r i"t.Vttutse to which phosphate grouPsmay bond'

H:ffi;;;;;;;;;" utoms on the rings of purine or pvrimidine bases'

C) cross-linking of the third and fifth carbon atoms of deoxyribose'

D)bondingbetweenpurinesanddeoxyriboseandbetweenpyrimidinesanddeoxyribose'E) bonds that form blt*een adenine and thymine and between guanine and cytosine'

Bio202

Quiz - DNA replicationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

\J1)WhichenzymeScatalvzeth"@.ofaDNAstrandinthe5'-3 'd i rect ion?A) primaseB) DNA ligaseC) DNA polymerasesD) topoisomerase

@n"ii.ur"

2) lCytosine makes up 38% of the nucleotides in a sample of DNA from an organism. What percent of theiildlettiiGs in this sample will be thymine? t c1 |@;n \0 lbpYtz+ + gA -- tVc)31 -$ ffiD) 38E) It cannot be determined from the information provided.

3) A new DNA strand only elongates in the 5'to 3'direction becauseA) DNA polymerase begins adding nucleotides at the 5'end.B) Okazaki fragments prevent elongation in the 3' to 5' direction.C) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end.D) replication must progress toward the replication fork.

@ONa polymerase adds nucleotides only to the free 3'end.

4) The problem of replicating the lagging strand of DNA-that is, adding bases in the 3' * 5' direction-uires which of the following?DNA ligaseRNA primersOkazaki fragmentsA and B onlyA, B, and C

5)fhat is the function of DNA ligase?

\!| covalent bonding of the 3'end of a new DNA fragment to the 5'end of a growing chainB) elongation of new DNA at a replication fork by addition of nucleotides to the existing chainC) the addition of methyl groups to bases of DNAD) unwinding of the double helix{E) Both B and C are correct.

6) All of the following are functions of PNA polvrlel€e jn DNA replication exceptA) covalently adding nucleotides to the new strands.B) proofreading each added nucleotide for correct base pairing.

!) replacing RNA primers with DNA.A

Q) initiating a polynucleotide strand.

Na*eKt, l l r* f i rn4hf i tyr1,0120108

reqA)B)c)D)

@

/ ) In making a movie, sometimes an editor will cut out one piece of film and insert another. This is analogousto which of the following?A) mismatch repair(9 excision repairC) transformation repairD) recombinational repairE) telomerase repair

ln the following list of DNAA) replicationB) information storage

properties, which relates to skin cancer

;Q exchange with other organisms

Q) repair of thymine dimersE) proofreading

A eukaryotic cell lacking telomerase wouldA) have a high probability of becoming cancerous.

' B) produce Okazaki fragments.C) be unable to replicate.

@ undergo a reduction in chromosome length.E) be highly sensitive to sunlight.

Which of the following help to hold the DNA strands apart while they are being replicated?A) helicaseB) ligaseC) DNA polymerase

@ single-stranded binding proteinsE) exonuclease

8)

e)

0)1

J

..--F

:-'Exam

M ULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) The 20 different amino acids found in polypeptides exhibit different chemical and physical propertiesbecause of differentA) carboxyl groups.Blamino groups.

6$ia" .hlir,, in groups).5 tertiarv structure.E) Both A and B are correct.

Refer to Figure 5.6 to answer the following questions.

r ' \

2) At which bond would water need to be added to achieve hydrolysis of the dipeptide shown, back to itsponent amino acids?

B)B D)D E)E

3) Which type of interaction stabilizes the cr-helix structure of proteins?A) hydrophobic interactionsB) nonpolar covalent bondsC) ionic interactions

/flftydrogen bondsA5 polar covalent bonds

4) What would be an expected consequence of chinging one amino acid in a particular protein?A) The primary structure would be changed,B) The tertiary structure might be changed.C) The biological activity of this protein might be altered.

Nu-" [&rtq f/rf]\

!) Only A and C are correct.

C)1,, B, and C are correct.

5) At which level of protein structure are interactions between R groups most importA) primaryB) secondarv^/<\

1Q)tertiaryV) quaternaryE) They are equally important at all levels.

ROROH\l l l l l l

)N-C-C-N-C-C-O-HH/ t l t t l t l t

l ' l I ' l ' ll l l r lA. B. C. D. E.

Figure 5.6

6) A change in a protein's three*dimensional shape or conformation due to disruption of hydrogen bonds,disulfide bridges, and ionic bonds is termedA) hydrolysis.B) stabilization.C) destabilization.D) renaturation.^4.

@denaturation.

7) Which of the following best describes the relationship between proteins, RNA, DNA, and genes in humans?

#IDNA -+ genes -+ RNA --+ proteins

D) genes --+ RNA --+ DNA -+ proteinsE) genes * proteins * RNA * DNA

8) A sequence of a DNA polymer consisting of 80 purines and 80 pyrimidines could have

E RNA * DNA + genes --+ proteins

@Oro,"rns--* RNA --* DNA ---+ genes

4'),160 cytosine and 160 thymine molecules.B) 8-0 uracil and 80 adenine molecules.

XtO adenine and 80 thymine molecules.(DAO adenine and 80 guanine molecules.T)both B and C.

9) lhe difference between the sugar in DNA and(@ contains less oxygen.Y) can form a double-stranded molecule.

\

the sugar in RNA is that the sugar in DNA

C) has a six-membered ring of carbon and nitrogen atoms.D) can attach to a phosphate, unlike the sugar in RNA.E) is a six-carbon sugar and the sugar in RNA is a five-carbo

10) Which of the following are nitrogen bases of the purine type?

;\] cytosit e and guanine(@,)guanine and adenine! adenine and thyamineD) thyamine and uridineE) uridine and cytosine

Bio202

enzyme a

A+B

Name Sil\ \<r{Zr€a

enzyme b

_+C

Quiz - Protein synthesis 4/ 13 /0s. Qtg,kf, X _y.r_1.;;I gT?.T - tlia "K,/.trilti;*#,i#H:'thoose the one arternative '',ut

u"liii*tS.,H*;'#;gf"' l;,lA;,htlX "r,i"fitfut*|rc

following questions refer to the following simple metabolic pathway:

1) A mutation results in a defective enzymg a. Which of the following would be a consequence of that mutation?

A) an accumulation of C and no production of A and B

B) an accumulation of B and no production of A and C

C) an accumulation of B and C and no production of A

D) an accumulation of A and B and no production of C

60" accumulation of A and no production of B and C\.t r

FIA'-rhrrc-.2) What is theft transciipt of eukaryotic 8:E{

tA) hRNA B) DNA ( c) h4RNAVV

E) rRNA

5,l

D) IRNA

3) If proteins were composed of only 12 different kinds of amino acids, what would be the smallest possible codonsize in a genetic system with four different nucleotides?

A)1 B)4 c)3 D)12

4) Which of the following is correct about a codon? It

A) consists of discrete amino acid regions.

B) catalyzes RNA synthesis.

€Puy code for the same amino acid as hnother codon.

D) consists of two nucleotides.

E) is the basic unit of the DNA

Where is the attachment site for RNA polymerase?

A) initiation region

B) regulator region

C) structural gene region

@romoter region

E) operator region

6) Which of the followin! helps to stabilize mRNA by inhibiting its degrgdation?

A) spliceosomes

B) a modified guanosine triphosphate

$oly(A) tail

D)snRNPs

E)TATA box

7) All of the following are found in prokaryotic messenger RNA ercepl

A)the AUG codon.

B) uracil.

Gil',,ror,r.Hh" UGA codon.

E) cytosine.

8) A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the IRNA that binds themRNA codon is

A)TTr.B) rruA.'@ruuFD"oEf either UAA or TAA, depending on wobble in the first base.

9) What are ribosomes composed of?(fttfr rRNA and protein

YmRNA, IRNA, rRNA, and protein

C) two subunits, each consisting of rRNA only

D) two subunits, each consisting of several proteins only

E)mRNA, rRNA, and protein

10) From the following list, which is the first event in translation in eukaryotes?

A) covalent bonding between the first two amino acids

B) elongation of the polypeptide

$ fairinS of activated methionine-tRNA to AUG of the messenger RNAJ

ding of the larger ribosomal subunit to smaller ribosome subunits

E) Both B and D occur simultaneously.

\I

\I

Bio2A2Quiz -Protein synthesis 2

E) an activating enzyme

4) What type of bonding is responsible for maintaining the shape of the IRNA molecule?

A) covalent bonding between sulfur atoms

B) ionic bonding between phosphates

-p*"ryia" bonding between amino acids

/p*arogen bonding between Uur" puiri /,/- E) van der Waals interactions between hydrogen atomf

B) ribosomes.

C) IRNA./^?->

/D)W^.L6-nr.re,

3\ yb*yAn anticodon part of?

/ 4xnrue7e)nNe

C)mRNA

D) a ribosome

5\ lPDYaf ribosomes composed of?

/'P9#rRNA and protein

-r4')mRNA, IRNA, rRNA, and protein

B) second IRNA before attaching to the ribosome.i7\t

fperytia" site (P site) of the ribosome only.

/O}ardino acid site (A site) of the ribosome only.c-/il Both A and C are correct.

.t-\v)(r\

' l - l

->t

- lFI

its, each consisting of several proteins onl

subunits, each consisting of rRNA only

mRNA, rRNA, and protein

6) When a ribosome first attaches to an nRNA molecule, one IRNA binds to the ribosome. The IRNA thatrecognizes the initiation codon binds to the

A) large ribosomal subunit only.

ruu*" *ChOi€ Hpcr-lnl26/a6

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Which of the following is correct about a codon? It

A) is the basic unit of the genetic code.

B) consists of discrete amino acid regions.

C) consists of two nucleotides.

D) caialyzes RNA synthesis.

2) All of the following are directly involved in translation except

A) amino acid-activating enzymes.

U

t

As a ribosome translocates along an mRNA molecule by one codon, which of the foilowing occurs?

A) The IRNA that was in the A site moves into the P site.

B) The IRNA that was in the P site moves into the A site.

C)The IRNA that was in the P site moves to the E site and isreleasefux

D)The tRNA that was in the A site departs from the ribosong".z/./

h A and C are correct. i'

What is one function of a signal peptide?

al the initiation of transcription

an nRNA molecule into the cisternal space of ER

frameshift mutation could result from

A) a base insertion only.

B) a base deletion only.

C) a base substitution only.

D) deletion of three consecutive bases.

an insertion or a deletion of a base.

Sickle-cell disease is probably the result of which kind of mutation?

\frameshift only

!)ioqdisjunction only

int only

nonsense only

\otir B and D

,"

Bio202

Quiz - Protein synthesis

A) 1,800

N^ " &*,f7(,,/

c)3 D) 100

November 1,2004

--dULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) What is the primary transcript that is generated by transcription of eucaryotic genes

A) IRNA 2foNe @PnNe ,efnNe

2) A particular triplet of bases in the coding sequence of DNA is 5'AGT 3'. The corresponding codon for themRNA transcribed is

- q cA

B)TCA.

C) UCA.

D) AGT.

E) either UCA or TCA, depending on wobble in the first base.

3) A particular eukaryotic protein is 300 amino acids long. Which of the following could be the maximum numberof nucleotides in the DNA that codes for the mRNA {

E)300 0

4) A portion of the genetic code is UUU = phenylalanine, GCC = alanine, AAA = lysine, and CCC = Proline.Assume the correct code places the amino acids phenylalanine, alanine, and lysine in a protein (in that order).Which of the followlng DNA sequences would substitute proline for alanine?

-'---@B)AAT-CGG-TTT

C)AAA-CCC-TTT

D)AAA-CCG-TTT

E)AAA-CGG-TTA

5) Which of the following is correct about a codon? It

(9"V code for the same amino acid as another codon.

Wis the basic unit of the genetic code.

pfconsists of discrete amino acid regions.

D) catalyzes RNA synthesis.

/consists of two nucleotides.

6) The genetic code is essentially the same for all organisms. From this, one can logically assume all of the

following except:

A) Codons usually translate into the same amino acids.

B) All organisms have a common ancestor.

C) A gene frorn an organism could theoretically be expressed by any other organism.

doD*o was the first genetic material.

L4qr\ - G,cc- AAA

AAA - GGG-TT(

E) Related organisms have many similar genes.

7) Where is the attachment site for RNA polymerase?

A) promoter region

B) operator region

@initiution region

D) structural gene region

flf regtlator region

8) Once transcribed, eukaryotic FRNA typically undergoes substantial alteration that includes

A) union with ribosomes'

fB\xcision of introns.

e)f u,sjon,.wjlhothernelvly,,trq4qc-rlb-e{mRNA,

D) fusion into circular forms known as plasmids.

E) linkage to histone molecules'

9) The first event of translation in eukaryotes (starting with methionine) is the

(DUut" pairing of pet-tRNA to AUG of the messenger RNA.

y'formingof polysomes.

,Ef covalent bonding between the first two amino acids.

D)binding of the large ribosomal subunit to AUG of mRNA.

E) joining of the ribosomal subunits.

10) During translation, chain elongation continues until what happens?

A)All tRNAs are emPtY.

B) The polypeptide is long enough.

C)No further amino acids are needed by the cell.

fl0huin terminator codons occur.

E) The ribosomes run off the end of mRNA.

X

+\w{}P* \"efvBio202

Quiz - Protein synthesisMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

L) A new form of life is discovered. It has a genetic code much like that of organisms on Earth except that-vt

vthere are five different DNA bases instead of foq-r and the base sequences are translated as doqblets instead

of triplets. How many different amino acids could be accommodated by this genetic code?.A)5 B)10 rc)zs D)64 E)32

^

2) Which of the following is correct about a codon? ItA) consists of two nulleotidesX

j) may code for the same amino acid as another codonl4'

!$ consists of discrete amino acid regions.D) catalyzes RNA synthesis.E) is the basic unit of the genetic code.{

3) Where is the attachment site for RNA polymerase?A) structural gene regionB) initiation region

fQpromoter region)JJ operator regionE) regulator region

4) All of the following are transcribed from DNA exceptA) protein. B) exons. C) rRNA. Stnrua. E) mRNA.

Which of the following is least related to the other items?

@translationB) TATA boxC) transcriptionD) template strandE) RNA polymerase II

A transcription unit that is 800 nucleotides long may use 1,200 nucleotides to make a protein consisting of

400 amino acids. This is best explained by the fact that($ many noncoding nucleotides are present.E) ther" is redundancy and ambiguity in the genetic code.C) many nucleotides are needed to code for each amino acid.D) nucleotides break off and are lost during the transcription process.E) there are termination exons near the beginning of mRNA.

5)

6)

All of the following are directlyA) mRNA.B) tRNA.C) ribosomes.

involved in translation except

Cp)oNn.)fl amino acid-activating enzymes.

101271

8) What is an anticodon Part of?

A) DNA

@ tnNeC) mRNAD) a ribosomeE) an activating enzyTe,

_ .

9) What are dbosomes comPosed of?

A) two subunits, each consisting of rRNA only

B) two subunits, each consisting of several proteins only

CIUoth rRNA and Proteinil) mRNA, rRNA, and ProteinE) mRNA, IRNA, rRNA, and Protein

1 0) Where is e:rkaryqfiEribogg!1al RNA ganscribed?

r A) the Golgi aPParatus r

I Blribosomes \V @ nucleoti

$

.!

D) X chromosomesE) prokaryotic cells onlY{

] .1)F-romthefoI lowingl ist ,whicho,h@in$@ineukaryotes?

@ elongation of the PolYPePtideB) base pairing or aciivatea methionine-tRNA to AUG of the messengerRNA

CjUir,air",g of lhe larger ribosomal subunit to smaller ribosome subunits

D) covalent bonding between the first two amino acids

E) Both B and D occur simultaneously'

\.f

Bio202Quiz - Gene regulationMULTIPLE CHOICE. Choose the one alternative that

J 1) In a nucleosome, what is the DNA wrapped around?A) polymerase moleculesB) ribosomesC) mRNA

6)hirton",\<.b,) nucleotus proteln

2) Which of the following statements is true?A) Heterochromatin is composed of DNA, while euchromatin is made of DEllA and RNA.B) Only euchromatin is found in the nucleus.

-/@H"t"ro"hromatin is highly condensed, while euchromatin is bcdmpact.D) Euchromatin is nof transcribed while heterochromatin is transcribed.E) Only euchromatin is visible under the light microscope.

3) What do pseudogenes and introns have in common?A) They code for RNA end products, rather than proteins.B) They both contain uracil.C) They have multiple promoter sites.D) Thev both code for histones.

@ fn"y are not expressed, nor do they code for functional proteins.

4) Muscle cells and nerve cells in one species of animal owe their differences in structure toA) having different genes.B) having different chromosomes.

;Q using different genetic codes.IP)

"*pressing different genes.

E) having unique ribosomes.

5) In which of the following would you expect to findA) tandem arrays for ribosomal genesB) pseudogenes

G inactivated mammalian X chromosomesD) globin genesE) transposons

the most methylation of DNA?

6) In eukaryotes, transcriotion is generally associated withA) euchromatin only.B) heterochromatin.only.C) very tightly packed DNA only.

both euchromatin and histone acetylation.

'Which of the following is an example of transcriptional control of gene expression?

@mRNa is stored irithe cytoplasm uni-nuua, u "orrtrot

rignul to initiate translation.B) mRNA exists for a specific time before it is degraded.{C) There is an amplification of genes for rRNA.,(

_PFNA processing occurs before mRNA exits the nucleus. f&ansiription fictors bind to the enhancer and promoter regions.\J

Nu."e Kf t t i f Erkr4hAff ' ]71107108 ' r

best completes the statement or answers the question.

/ \

{wnirnof the following is leastrelated

,/ A) amino acids' q"biquitin

fC) lnhancers\Dy'protein degradation

E) proteasomes

to the others?

-\

- l,Q promoting the degradation of specific mRNAs. 1Q)binding to receptors and promoting transcription of certain regions of DNA.

E) promoting the formation of looped domains in certain regions of DNA.{/

1.y1 All of the following aqe potential control meshaJrisfns for regulatign olgene exp{gssioo:irr eukaryotic

/ organisms except/ A) the degradation of mRNA.

B) the transport of mRNA from the nucleus.,A'

(!) alternate splicingP) transcription.

/ffpt of the above

Bio202Quiz -MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

.J 1) Which of the following events is necessary for the production of a malignant tumor?A) activation of an oncogene in the cellB) the inactivation of tumor-suppressor genes within the cellC) the presence of mutagenic substances within the cell's environmentD) the presence of a retrovirus within the cell

@eotn A and B are necessary.

2) V[hich of the following is not a mechanism whereby a proto-oncogene is converted to an oncogene?

@methylation of basesB) point mutation XC) gene transpositionD) gene amplificationE) chromosome translocationX

3) Proto-oncogenes can be converted to oncogenes by various genetic changes. Which of these mechanisms

does not contribute to an abnormal cell cycle?A) Chromosomes break and fragments are translocated from one chromosome to another.

!) A gene is transposed to a more active promoter'tu

G) /*ttu copies of the gene are made, thereby enhancing expression.DlFoint mutations occur that result in a protein more resistant to degradation.

q) nNe methylation takes place.

4) Which of the following statements concerning proto-oncogenes is false?A) They code for proteins associated with cell growth.XB) They are similar to oncogenes found in retroviruses'X

@ fhey are produced by somatic mutations induced by carcinogenic substances.

D) They are involved in producing proteins for cell adhesion.E) They are genes that code for proteins involved in cell division.X

5) The incidence of cancer increases dramatically with age because

become more active with age.we age, normal cell division inhibitors cease to function.

the longer we live, the more mutations accumulate.E) tumor-suppressor genes are no longer able to repair damaged DNA.

6) What does the operon model attempt to explain?

@ the control mechhnism of gene expression in bacteriaB) bacterial resistance to antibioticsC) how genes move between homologous regions of DNAD) the mechanism of viral attachment to a host cellE) horizontal transmission of plant viruses

r r lame Kt l l i t B tnCJ h Orn17 I 241 08

7) The tryptophan synthetase operon uses glucose to synthesize tryptophan. Repressible operons such as this

one areA) permanently turned on.B) turned on only when tryptophan is present in the growth medium'

C) turned off only when glucose is present in the growth medium.

D) turned on only when glucose is present in the growth medium.

@turned off whenever tryptophan is added to the growth medium'

8) When is the lactose oPeron likely to be transcribed? When

A) there is more glucose in the cell than lactose.B) there is more lactose in the cell than glucose'

C) there is lactose but no glucose in the cell.D) the cyclic AMP levels are high within the cell.

ArUoth C and D are correct.

9) Of the following, which is least related to the others?

A) corepressorB) repressorC) inducer

(D) transposonE) cAMP receptor protein

i

10) What is the function of the operator locus of the lactose operon?

A) terminate production of repressor molecules I

B) idqntify the substrate allolactoseC) initiate production of mRNA

@control ih" bittdittg of RNA polymerase to the operator region

El Uina steroid hormones and control translation