Chapter 13 Practice Test

7/24/2019 Chapter 13 Practice Test

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1. During Griffith's experiments with Streptococcus pneumoniae in mice, material from _____

bacteria transformed _____ bacteria.

a) heat-killed nonvirulent ... living virulent

b) heat-killed virulent ... living nonvirulentc) living nonvirulent ... heat-killed virulent

d) living virulent ... heat-killed nonvirulent

2. ver! and his colleagues' "#$$ experiment showed that D% _____.

3. scientist assembles a bacteriophage with the protein coat of phage & and the D% of

phage &$. (f this composite phage were allowed to infect a bacterium, the phages produced in

the host cell would have _____.

a) the protein of &$ and the D% of &

b) the protein and D% of &c) a mixture of the D% and proteins of both phages

d) the protein and D% of &$

e) the protein of & and the D% of &$

4. (n an important experiment, a radioactivel! labeled bacteriophage was allowed to infect bacteria. (n a first trial, the phage contained radioactive D%, and radioactivit! was detected

inside the bacteria. %ext, phage containing radioactive protein was used, and the radioactivit!

was not detected inside the bacteria. &hese experiments led to the conclusion that _____.

a) genes are on chromosomes b) bacteriophages can infect bacteria

c) the genetic material of the phage is protein

d) the genetic material of the phage is D%

e) D% is made of nucleotides

5. p until *ershe! and +hase showed that D% was the genetic molecule, what molecule was

considered the best candidate for carr!ing genetic information and wh!

a) sterols because of the different variations on their ring structure

b) amino acids because of all the wa!s the! can oin together

a) consists of sugars, phosphate groups, and bases

b) uses three bases to code for one amino acidc) contains adenine, guanine, th!mine, and c!tosined) has two strands held together with h!drogen bonds

e) was the substance that transformed the bacteria in Griffith's experiment



c) carboh!drates because the! are found in abundance in all organisms

d) proteins because the! were thought to be the onl! molecule with both the variet! and

specificit! of function to account for the arra! of heritable traits observede) nucleoside triphosphates because of the abilit! to add and remove phosphate groups

6. onomers for the s!nthesis of D% are called _____.

a) disaccharides b) amino acids

c) monosaccharides

d) nucleotidese) fatt! acids

7. +hargaff found that for D% _____.

a) the ratio of to G is close to "/" and the ratio of & to + is close to "/"

b) the ratio of to & is close to "/" and the ratio of G to + is close to "/"

c) 0 & 1 G 0 +d) the ratio of to + is close to "/" and the ratio of G to & is close to "/"

e) 0 & 1 234 of the total bases

8. 5hat techni6ue was most helpful to 5atson and +rick in developing their model for the

structure of D%

a) transgenic animals b) 7-ra! cr!stallograph!

c) electrophoresis

d) radioactive labelinge) cloned D%

9. (n D%, the two purines are _____, and the two p!rimidines are _____.

a) adenine and th!mine ... c!tosine and guanine

b) c!tosine and guanine ... adenine and th!minec) adenine and c!tosine ... guanine and th!mine

d) adenine and guanine ... c!tosine and th!mine

e) c!tosine and th!mine ... adenine and guanine

10. 5hich of the following is correct

a) denine forms two covalent bonds with th!mine8 guanine forms three covalent bondswith c!tosine.

b) denine forms two h!drogen bonds with guanine8 th!mine forms three h!drogen bondswith c!tosine.

c) denine forms two h!drogen bonds with th!mine8 guanine forms three h!drogen bonds

with c!tosine.d) denine forms three h!drogen bonds with th!mine8 guanine forms two h!drogen bonds

with c!tosine.



e) denine forms three covalent bonds with th!mine8 guanine forms two covalent bonds

with c!tosine.

11. &he two sugar-phosphate strands that form the rungs of a D% double helix are oined to

each other through _____.

a) 2' deox!ribose and phosphate bonds b) covalent bonds between carbon atoms in deox!ribose molecules

c) covalent bonds between nitrogen atoms in adenine and in th!mine

d) ionic bonds between guanine and c!tosinee) h!drogen bonds between nucleotide bases

12. &he information in D% is contained in _____.

a) the variation in the structure of nucleotides that make up the D% molecule

b) the se6uence of nucleotides along the length of the two strands of the D% moleculec) the se6uence of amino acids that makes up the D% molecule

d) the t!pes of sugars used in making the D% moleculee) ll of the listed responses are correct.

13. 5ho is credited with explaining the structure of the D% double helix

a) Griffith

b) 5atson and +rick

c) 9acob and onodd) *ershe! and +hase

e) ver!, c+art!, and ac:eod

14. 5hich of the following attributes of D% is most crucial to its accurate duplication

a) its deox!ribose sugar and phosphate groups

b) its specific base pairing and h!drogen bondingc) its phosphodiester linkages and complementar! strands

d) its helical nature and h!drogen bonding

e) its specific se6uence of bases

15. During the replication of D%, _____.

a) the cell undergoes mitosis

b) the reaction is catal!;ed b! <% pol!merase

c) both strands of a molecule act as templatesd) onl! one strand of the molecule acts as a template

e) errors never occur



16. &he experiments of eselson and =tahl showed that D% _____.

a) is composed of nucleotides

b) is the genetic materialc) replicates in a semiconservative fashion

d) codes for the se6uence of amino acids in proteins

e) contains complementar! base pairing

17. &he D% structures of prokar!otes and eukar!otes are different in several wa!s, but one wa!

in which the! are the same is that _____.

a) both have a single circular chromosome

b) most of the D% is in the form of plasmids

c) the D% is packaged into several linear chromosomes

d) both have a sugar-phosphate backbonee) histones are present in the nucleosomes

18. 5hich of the following statements about replication origins is correct

a) (n bacteria, the D% se6uence at the origin is recogni;ed b! specific proteins that then

bind to the origin.

b) &he two strands of D% at the origin are separated, allowing the formation of areplication bubble.

c) (n both prokar!otes and eukar!otes, replication proceeds in both directions from each

origin.d) >acterial chromosomes have a single origin, but eukar!otic chromosomes have man!

origins.

e) ll of the listed responses are correct.

19. t each end of a D% replication bubble is _____.a) a telomere

b) an origin of replication

c) a gene

d) a replication fork e) a ribosome

20. &he role of D% pol!merases in D% replication is to _____.

a) separate the two strands of D%

b) attach free nucleotides to the new D% strand

c) s!nthesi;e an <% primer to initiate D% strand s!nthesisd) link together short strands of D%


21. &he rate of elongation in prokar!otes is _____ the rate in eukar!otes.

a) sometimes faster and sometimes slower than

b) much slower than



c) about the same speed as

d) much faster than

e) &he rates are not comparable, because elongation onl! occurs in prokar!otes.

22. &he two strands of a D% double helix are antiparallel. &his means that _____.

a) the! both run in the ?' to 2' direction

b) one strand is actuall! composed of <%c) the two strands are mirror images

d) one strand runs in the 2' to ?' direction, and the other runs in the ?' to 2' direction

e) onl! one of the two strands can be used as a template for replication, because D% pol!merase onl! works in one direction

23. @ne strand of a D% molecule has the base se6uence 2A-&GG&-?A. &he complementar!

base se6uence on the other strand of D% will be ?A-_____-2A.

a) &GG&

b) &GG&c) &GGd) ++

e) &&++

24. D% pol!merase adds nucleotides to the _____ of the leading strands, and to the _____ of

the lagging strands B@ka;aki fragments).

a) ?A end ... ?A end b) 2A end ... ?A end

c) sugar group ... phosphate group

d) 2A end ... 2A ende) ?A end ... 2A end

25. 5hat en;!me oins @ka;aki fragments

a) helicase

b) primase

c) topoisomerased) D% ligase

e) D% pol!merase

26. fter the formation of a replication bubble, which of the following is the correct se6uence of

en;!mes used for the s!nthesis of the lagging D% strand

a) helicases, primase, ligase, D% pol!merases b) helicases, primase, D% pol!merases, ligase

c) ligase, primase, D% pol!merases, helicases

d) helicases, D% pol!merases, primase, ligasee) primase, helicases, D% pol!merases, ligase



27. 5hich of the following components is re6uired for D% replication

a) transfer <%

b) sucrases

c) proteasesd) ribosomes

e) <% primer

28. &he removal of the <% primer and addition of D% nucleotides to the ?' end of @ka;aki

fragments in its place is carried out b! _____.

a) nuclease b) primase

c) D% pol!merase (((

d) D% pol!merase (

e) ligase

29. &he unwinding of D% at the replication fork causes twisting and strain in the D% ahead of

the fork, which is relieved b! an en;!me called _____.

a) primase b) topoisomerase

c) ligase

d) relievasee) ribosomes

30. @nce the D% at the replication fork is unwound b! helicases, what prevents the two strands

from coming back together to re-form a double helix

a) D% pol!merase follows the helicase so closel! that there is no chance for the strands to

come back together. b) =ingle-strand binding proteins bind the unwound D% and prevent the double helix from

re-forming.

c) &he helicase modifies the D% in such a wa! as to eliminate the affinit! between the two

strands.d) @ne of the strands is rapidl! degraded, preventing the double helix from re-forming.

e) &he helicase pushes the two strands so far apart that the! have no chance of finding each

other.

31. 5hich description of D% replication is correct

a) :igase assembles single-stranded codons, then pol!merase knits these codons togetherinto a D% strand.

b) &he two strands separate, and each one receives a complementar! strand of <%. &henthis <% serves as a template for the assembl! of man! new strands of D%.

c) :igase separates the two strands of the D% double helix. &hen, D% pol!merase

s!nthesi;es the leading strand and primase s!nthesi;es the lagging strand.d) &he two strands of D% separate, and restriction en;!mes cut up one strand. &hen, the

D% pol!merase s!nthesi;es two new strands out of the old ones.



e) *elicases separate the two strands of the double helix, and D% pol!merases then

construct two new strands using each of the original strands as templates.

32. (n what wa!Bs) is our traditional representation of D% pol!merase molecules moving like

locomotives along a track inaccurate

a) &he proteins involved in replication do not move8 instead, D% is drawn through the

complex.

b) D% pol!merase acts as part of a large complex of proteins, not like a single locomotive.

c) :ike a train on a track, D% pol!merase must add nucleotides se6uentiall!. (t cannot ump around.

d) >oth the first and second answers are correct.e) D% pol!merase completes replication of one strand and then begins the other.

33. &he incorporation of an incorrect base into the D% during replication _____.

a) is virtuall! impossible, as the accurac! of D% pol!merase is such that errors almostnever occur

b) cannot be repaired, and a new mutation will invariabl! result

c) will almost certainl! lead to the death of the cell

d) will trigger the cell to destro! the new strand, and replication will begin againe) can be repaired b! the mismatch repair s!stem

34. 5hich set of en;!mes is involved in nucleotide excision repair

a) h!drolase, nuclease, and ligase

b) D% pol!merase, helicase, primasec) nuclease, D% pol!merase, primase

d) nuclease, D% pol!merase, and ligase

e) ligase, nuclease, and primase

35. (ndividuals with the disorder xeroderma pigmentosum _____.

a) have difficult! repairing th!mine dimers

b) often have inherited defects in the nucleotide excision repair s!stem

c) are h!persensitive to sunlightd) have high rates of skin cancer


36. nlike prokar!otic D% replication, replication of eukar!otic chromosomes _____.



a) cannot be completed b! D% pol!merase

b) has a single origin

c) is error freed) is semiconservative

e) involves two leading strands and no lagging strands

37. &elomeres _____.

a) get longer with continued cell division b) are found in both prokar!otic and eukar!otic cells

c) remain the same regardless of the fre6uenc! of cell division

d) are shorter for !ounger individualse) get shorter with continued cell division

38. &elomerase _____.

a) prevents the loss of centromeric D%

b) slows the rate of cancer cell growth

c) is an en;!me that lengthens telomeresd) splits telomeres

e) speeds cell aging

39. 5hat is the maor difference between bacterial chromosomes and eukar!otic chromosomes

a) &here is no difference between bacterial and eukar!otic chromosomes.

b) >acterial chromosomes have much more protein associated with the D% than

eukar!otes.c) Cukar!otes have a single circular chromosome whereas bacteria have several linear

chromosomes.

d) >acteria have a single circular chromosome whereas eukar!otes have several linear

chromosomes.e) &he D% of bacterial chromosomes has a slightl! different structure.

40. ut the following D%-containing entities in order according to the amount of D% found in

their genomes.

a) virus, bacteria, eukar!ote

b) eukar!ote, virus, bacteriac) bacteria, eukar!ote, virus

d) bacteria, virus, eukar!ote

e) &he! all have about the same amount of D%.

41. 5h! were man! of the earl! experiments on D% carried out on viruses and bacteria

a) &heir chromosomes have a simpler structure. b) &he! can interact with each other.

c) &he! have relativel! small genomes.

d) &he! have short generation times.e) ll of the responses are true.

42. &he Ebeads on a stringE seen in interphase chromatin are _____.



a) histone tails

b) nucleoids

c) nucleosomesd) looped domains

e) heterochromatin

43. F+ul de estas figuras representa el modelo semiconservativo del D%

44. F+ul de los siguientes representa la en;ima D% pol!merase (((

a)

b) +

c) C

d) ! C

e) ! +

a)

b)

c)

ED

CB

A



45. F+ul de los siguientes es responsable por la catali;aciHn de la formaciHn del I<%

primerJf)g)h)

a)

b) >

c) +

d) D

e) Ci)

)

k)

l)

m) areo

n)

o) ___1. semiconservative

model

p)

q) ___2. Chromatin

r)

s) ___3. ntiparallel

t)

!) ___4. do!"le heli#

v)$) ___5. %!cleoid

#)

&) ___6. ori'in o(

replication

;)

aa) ___7. acteriopha'es

ab)

ac) ___8. mismatch repair

ad)

a) virus that infects bacteria8 also called a

phage.

b) &he complex of D% and proteins that makes

up eukar!otic chromosomes. 5hen the cell is

not dividing, chromatin exists in its dispersed

form, as a mass of ver! long, thin fibers that are

not visible with a light microscope.c) &!pe of D% replication in which the

replicated double helix consists of one oldstrand, derived from the parental molecule, and

one newl! made strand.

d) <eferring to the arrangement of the sugar-

phosphate backbones in a D% double helix

Bthe! run in opposite 2A K ?A directions).

e) =ite where the replication of a D% molecule

begins, consisting of a specific se6uence of

nucleotides.

f) &he cellular process that uses specific en;!mes

to remove and replace incorrectl! paired

nucleotides.g) &he form of native D%, referring to its two

adacent antiparallel pol!nucleotide strands

wound around an imaginar! axis into a spiral

shape.h) non-membrane-bounded region in a

prokar!otic cell where the D% is



concentrated.

ae)

af) +ontesta

". (f a single cop! of double stranded D% molecule was to undergo replication, how man!copies of double stranded D% will be present after

a. rounds of replication

ag) b. ? rounds of replication

ah)

c. $ rounds of replicationai)

. +< Bol!merase chain reaction) is a techni6ue routinel! used in research laboratories to

amplif! specific regions within D%. &he idea behind the techni6ue is to enable artificial

D% replication targeted to regions of interest within the D%.a)

a. 5hich of the following +< reactions will work and wh!

ak)al) *eact

ion

am)

*eacti

on

an)*ea

ctio

n C

ao)*ea

ctio

n +

ap)+% a6) LC= ar) %@ as) LC= at) LC=

a!)+%

pol&meraseav) %@

aw)

LC=ax) LC= a!) LC=

a,) -rimers ba) LC=

bb) LC

= bc) LC= bd) LC=

"e)d%-s bf) LC= bg) LC

= bh) LC= bi) %@

"/) -C* reaction

!((er bk) LC=

bl) LC

=

bm)

LC= bn) LC=

"o)

b. (f we start with 2 copies of double stranded D% molecule, after three rounds of

+< how man! molecules of D% will be present

bp) b6)

br) bs)

bt)

bu)

c. (f the D% pol!merase used in the +< reaction adds #33 nucleotides in one minute



how man! seconds will it take for the en;!me to complete replication of D% that is

$M33 nucleotides long

"v)

bw)bx)

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Chapter 13 Practice Test