2002 released exam

8/2/2019 2002 Released Exam

1/18

1:

I _

I f t i i u . " ,IBIOLOGYSECTION I

Time-l hour and 30minutesDirections: Each of the questions or incomplete statements below is followed by five suggested answers orcompletions. Select the one that is best in each case and then fill in the corresponding oval on the answer sheet.1. In humans. the mv virus primarily attacks whichof the following types of cells?

(A) Epidermal cells(B) Red blood cells(C) White blood cells(D) Glial cells(E) Neurons

3. A biologist counted 2,500 cells from an embryoon a m icroscope slide and recorded the followingdata.StageProphaseMetaphase-AnaphaseTelophaseInterphase _

Total

Number of Cells125505025

2,250-2,500

2. In a n experiment on birds learning to sing, youngmale chicks were exposed only to the songs sungby another species.Later, as they approachedmaturity. songs of their own species were playedto them. When the-birds reached maturity. theywere able to sing neither the typical song of theirspecies nor the full Song O f the second species.Which of the following accourits for this result?(A) Birds innately sing the song typical of their

species. :(B) Birds pass through a critical period early in

life when learning their species-typical songis possible. - -(C) Birds can learn their typical song ifthey hear. it at any time.(D) Birds must b e able to practice their song in

order to develop it. -(E) Birds are capable of imitating any song that- they .hear,

Ifthese cells had been dividing randomly. it couldbe-reasonably concluded that -(A) the duration of anaphase is approximatelyone-half that of telophase(B) prophase is approximately three times as long- as telophase _(C)metaphase is the shortest stage of the cellcycle(D) interphase is the longest stage of the cell

cycle(E) the chromosomes can first be seen inprophase

4. The different species of finches on the GalapagosIslands are believed to have arisen as a result ofnatural selection acting on populations of finchesthat had experienced(A) convergent evolution_(B) -g en e f low(C) the bottleneck effect(0) geographic isolation(E) hybrid sterility

-20~~APBiology Released Exam Excerpt" -L


2/18

5. Which of the following describes the mechanismby which a plant stem grows toward light?(A) The plant seeks light in order to maximize

photosynthesis.(B) Nervelike impulses stimulate contractile cells

. on the lighted side. of the stem.(C) Cells o n the dark side of the stem elongate

more than those on the ligbted side.(D) The plant grows into an open area where its

leaves will not be shaded by competingplants.

(E) The greater energy supply on the lighted sideof the stem stimulates. metabolism andgrowth on that side.

6. The LEAST effective means of controlling pestspecies such as rats or roaches over a long periodof time is generally.to(A) limit food supplies(B) reduce the number of potential habitats(C) distribute pesticides throughout the habitat(D) introduce predators of the pest(E) introduce a disease which affects only the

pest7. Which of the following levels of organization

includes all of the others?(A) Population

. (B) Ecosystem(C) Community(D) Organism(E) Habitat

...:.-:: .

lf i IM' '8. All of the following statements concerning

characteristics of predator-prey relationships arecorrect EXCEPT :(A) A rise in the population of prey is often

followed by a rise in the population of.predators.

(B) A rise in the population of predators isfollowed by a decrease in the populationof prey.

(C) Camouflage is an adaptation that protectsprey.(D) The production of large numbers of offspringwithin very short periods of time ensures thesurvival of some prey populations.

(E) TIre population of predators most ofteneliminates the population of prey.

9. The function of which of the following organellesdirectly requires oxygen?(A) Ribosome(B) Mitochondrion(C) Nucleus(D) Centriole

. (E) Golgi apparatus..10. Flowering plants are.capable of fertilization

in the absence of water because the(A) processes o f pollination and fertilization

occur in the soil(B) pollen tubes deliver the sperm to th e eggs(C) eggs develop without sperm by

parthenogenesis ;(D) .eggs have a 'structure that aids in their

dispersal by wind ..(E) sperm contain large amounts of cytoplasm

2 2 00 2 AP B io lo gy Released E x a m . E xc erp t ..


3/18

.

l i # U t . ] i I ,

11 . A daptation s that h ave enabled v erte bra tes tosu rvive o n lan d includ e all of th e, follow ingEXCEPT' .(A) a water-resistant epidermis(B) development of a bony skeleton(C) development of lungs(D) ex te rna l fe rt il iz a ti on(E) embryos e nc lo se d w ith in m em bra ne s

12. An animal that has a high surface-area-to-volume. ratio of the body, a nd ta ke s in al l the o xy gen itn ee ds th ro ug h its o ute r e pith elium is mo st lik elyw hich of the fol lowing?(A) a fish(B) an earthwonn(C) a m ammal(0) a n in se ct(E) a s nake

1 3. T o ad s in a -p artic ula r population vary . i n size. Ascientist o bserv es th at in th is p op ula tio n, largemales mate w ith fem ales sig nificantly m ore oftenthan small m ales d o. A ll-th e follo wing are plausiblehypotheses to explain this observation EX CE PT : .(A) Females select la rg e ma le s more often than

they select small males as mates.(B) Small females are more likely to mate withsm all m ales andlarge fem ales are m ore

Iikely to m ate w ith large m ales.(C) Large males a re success fu l in competing fa tmates m ore often than sm all m ales are.(0) Larg e m ales oc cu py more b re ed ing territory. than small males do. .(E) T he c alls p ro du ce d by large males are moreattractive to f em ale s th an th e calls m ade bysmall males.

14. In the development o f a s ee dlin g. which of the'. fo llow ing w ill be th e last to o cc ur ?(A) In itia tio n o f the breakdow n of the food reserve(B) Initiation of cell division in the root meristem(C) E mergence of the root(0) Expansion and greening of the first true

f olia ge le av es(E) Im bib itio n o f w ate r by th e se ed

15. Which of the following behaviors involves theLEAST learning? .:(A) A l ion captur ing its prey(B) A newborn human grasping something placedin~b~ .(C) A mouse finding food in the kitchen of a. house(D) A mockingbird singing the song of a different

species(E) A c himp an ze e fmdin g its way through a forest

16. Inmost v erte bra te s. th e spenn cell normallycontributes which of the foUowing to the neworganism?(A) Many mitochondria(B) S ig n if ic an t amoun ts of RNA(C) A h ap lo id c om plemen t o f c hromo somes(D) Most of the cytoplasm of tbezygote(E) Two s ex chr omosomes

17. Most cells that have becom e transform ed iritocancer cells have which of the fol lowingcharacteristics when compared to normal. healthycells? .'(A ) Shorter cell cycle(B) More carefully regulated rates of cell division(C) Lower rates o f m i to sis(D) H ig her ra tes o f p ro te in tran sla tio n(E) Id en tica l DNA

2002 AP Biol og y Rel ea sed E x a m Excerpt 3 ...


4/18

18. Iforganisms A, B. and C belong to the sameorder but to different families a n d if organisms D,E, and F belong to the same family but todifferent genera, w hich of the follow ing pairs oforganisms would be expected to show the greatestdegree of structural homology'l(A) A and B(B) A and C(C) Band D(D) C and F(E) E'and F

1~.Aprokaryotic cell has which of the following?(A ) .Cent rio le s(B) Lysosomes(C) Plasma membrane(0) Mitochondria(E) Endoplasmic. reticulum

20. Which of the following statements regardingcoenzymes i~true?(A). They are essential fo r metabolic reactions in

animals but not in plants.- (B) They can facilitate metabolic reactions by.combining w it h e nz yme s at their activesites. .(C) They are minerals that alter the pH of cells'and thus increase the.probability of

chemical reactions.(D) They are synthesized in the roughendoplasmic reticulum of eukaryotic cells,(E) They typically work best at te~raturesbelow 3 7OC .

1 - 1 [ " , 121. An animal with anterior. posterior, dorsal, andventral surfaces on its body must exhibit. .

(A) protostomic development(B) coelomate development(C) segmentation(D) radial symmetry(E) bilateral symmetry

22. The fruit produced by angiosperms is anevolutionary adaptation that most often( A ) n ou ri sh es the se ed s w ith in th e fru it o n rip en in g(B) aids in seed dispersal .(C) attracts pollinators(D) inhibits seed germination until favorableenvironmental conditions occur(E) provides an energy source for the plant eggcell prior to fertilization

23. which of the following types of chemicals releasedinto the air by female gypsy moths and femalesilk.moths attract males of their respective mothspecies? .(A ) E cd yso nes.(B) Pheromones(C) Auxins(0) Phytotoxins(E) Neurotransmitters

24. Which of the following best describesopportunistic, or r-strategy, organisms?(A) They reach sexual niaturity rapidly.(B) .They reach their adult size slowly.(C) They attain a large b o d y size;(D) They live for a long time ....(E) The size of their population remains fairly

constant.

4 2002 AP B iology Released ~ Excerpt

.


5/18

Ii

I1.!

lm n lIP25. Which of the following tennsrefers to both the

movement of a ribosome along a piece of mRNAand the movement of a piece of one chromosometo another. chromosome?(A) 'Iransduction(B) Transgenesis(C) Transformation(D ) T r ans locat ion(E) Transplantation

26_ Which of the following hormones is directly. responsible for the maintenance of the uterinelining during pregnancy ill mammals?(A) Melatonin. (B) Oxytocin(C) Progesterone(D) Prolactin(E) FSH (Follicle-stimulating hormone)

27. The fact that tracheophytes can survive on land isdue to which of the following?(A) Alternation of generations(B) Adominant gametophyte stage(C) .Adaptation to damp habitats(D) Water transport through vascular tissues(E) Mechanisms other than photosynthesis for

.. carbohydrate production28 _ As the initial cleavage divisions proceed in a frog

embryo, which of the followingresults?(A) The embryo increases in size.(B) The cytoplasmic content of the individual

cells increases.(C) The yolk mass increases in size.(0) Individual cells become smaller,(E) Individual cells become haploid.

29_ Which of the following provides the weakestevidence that mitochondria were once free-livingprokaryotes?(A) Mitochondrial ribosomes resemble those ofprokaryotes, - .(B) Mitochondria have DNA that is circular and

does not have.associated protein.(C) Enzyme pathways au mitochondrial

membranes resemble those found on modernprokaryote membranes,

(D) Mitochondria reproduce by a process similarto binary fission. .

(E) Mitochondria and prokaryotes both are foundin a variety of sizes.

30. Which of the following is an actively dividingtissue in plants?_ (A) Cambium(B) Xylem(C) Endodermis(D) Phloem(E) Pith

31. Analysis of DNA sequences from two individuals. o f the same species results in a greater estimate .of genetic variability than does analysis-ofamlnoacid sequences from the s a m e individuals because(A) different DNA sequences ca n code for the.. . same amine acid - .(B) some amino acid variations cannot be'

detected by protein electrophoresis(C) DNA sequencing is amore reliable technique. than protein electrophoresis(D) proteins are more easily damaged-than ~

is 'DNA(E) DNA is more heat-sensitive and thereforeva ri es more

- ... 2 0 02 AP B io lo gy R el ea se d E xam Excerpt .5


6/18

;;. : ,

, ", ' :jj!

!'iiII! :f ,

.]

32. Which of the following is correct concerningdevelopment of embryos in animals but not in

, plants?(A) Gastrulation occurs within the embryo.(B) Fertilization produces a diploid embryo.(C) -Bmbryonic cell divisions are mitotic.(D) Fusion o f gametes results in a' zygote.(E) Cell differentiation occurs.

33. Which of the following physiological effectswould likely occur first in a volunteer who was 'breathing ai r from which the CO2 was removed?'(A) Decreased blood pH(B) Decreased respiratory rate(C) Increased respiratory rate(D) Increased pulse rate,(E) Increased blood pressure

34. Which of the following best describes why thepolymerase chain reaction is a standard techniqueused in molecular biology research?(A) It uses inexpensive materials and producesperfect results.(B) It can-purify specific sections of a DNA

molecule.(C) It can produce birge amounts o f specific

DNA sequences.(D) It can duplicate the ent i re human genome,'(E) It can produce large amounts of mRNA., '. 35. Double fertilization in an ovule of a flowering

, plant results in which of the following?(A) Two embryos(B) .Two seeds in a' fruit(C) One embryo and one endosperm(D) Two fniits joined together ,(E) One endosperm and one cotyledon

" f i n ~ n "36. Which of the following best describes the

cells that result f r o m th e process of meiosis inmammals?(A) They, ar e diploid." ,(B) They can be used to repair injuries.(C) They a r e genetically different from the par

cell. '(D) They are genetically identical to all the oth

cells in the body.(E) They are identical to each other.

37. The functionof which of the following structureis NOT directly related to diffusion or activetransport across its membranes?(A) Aorta(B) Small intestine(C) Nephron tubule'(D) Capillary(E) Alveolus

38. A part of the brain used in the transfer of infor-mation from one cerebral hemisphere to theother is the '(A) medulla oblongata'(B) corpus callosum

, (e) cerebellum, (D) hypothalamus,(E) pituitary

39. Fruits often ripen faster .when placed in closed-paper, bags because of the effq:t of'(A) 'cytokinin(B) abscisic acid(C) CO2~D) gibberellin(E) eth ylene

6 2 00 2 A P ~ io lQ gy R ele ase d EX am E xc erp t' ..


7/18

40. Simple diffusion and facilitated diffusion arerelated in that both(A) r equ ir e p ro te in car ri er s(B) .depend on a concentration gradient(C) occur via contractions of cytoskeletal

elements attached to membrane proteins(D) are endergonic processes a n d thus require

the hydrolysis of ATP(E) occur in eukaryotic cells but not in

prokaryotic cells41. Which of the following statements about

mitochondrial chemiosmosis is NOT true?(A) A proton gradient is established across the

inner membrane of the mitochondrion.(B) The potential energy released from themitochondrial proton gradient is used to

produce ATP.(C) TIle mitochondrial p ro ton g rad ien t p rov idesenergy for muscle contraction. 'CD) Proteins embedded in the inner mitochondrial

membrane play an important role in ATPsynthesis. .(E) Heat energy is required to establish the

.electron ~pDJt chain,42. A TP serves as a common energy source fororganisms because .

(A) it is the smallest energy molecule(B) it stores the least energy of any energy source(C) its energy-can be easily transferred to do

cellular work ,( 1 it is extremely stable and, can be stored in the.' ' cell for long periods oftime

(E) traces of it have been found in fossils -of .ancient organisms dating back to thebeginning of life on Earth

43: A spermatocyte produces the following foursperm cells.

These cells are the result of nondisjunction duringwhich of the following phases?. '.(A) Interphase (0.1 or G2)(B) Interphase (S) ,(C) Mitosis(D) Meiosis I(E) Meiosis II

44. Which metabolic process is common to bothaerobic cellular respiration and alcoholicfermentation?(A) Krebs cycle(B) Glycolysis .(C) Electron transport chain(0) Conversion of pyruvic acid to acetyl CoA(E) 'Production of.a proton gradient

45. Which of the following is responsible for thecohesive property of water? .(A) Hydrogen bonds between the oxygen atoms

of two adjacent water molecules(B) Covalent bonds between the hydrogen "atomsof two adjacent water molecules

(e) Hydrogen bonds between the oxygen atom of, one water molecule, wid a hydrogen atom of

another water molecule'(0) Covalent bonds between the oxygen atom of

one water molecule and a hydrogen atom ofanother water molecule ,

(E) Hydrogen bonds between water moleculesand othertypes of molecules

2 0 02 AP B io lo gy R ele as ed Exam ~erpt. "


8/18

l - m i t . " "46. A ll of th e f ollo w in g c orr ec tI y d escrib e th e fate of

the em bryonic layers of a vertebrate E XC EP T(A ) neural tube and epiderm is develop from

ectoderm(B ) linings of digestive organs and lungs developfrom endoderm "(C) n oto ch ord a nd k id ney s de velo p frome n d o d e n n(D) sk ele ta l m usc le s an d h eart develop frommesoderm " "

(E ) reprodu ctive org ans and blood vessels"d ev elo p from mes od erm

47. W hich of the follow ing processes is associated" with som e prokaryotic cells b ut not withe uka ry ot ic c ell s?"(A) Photosynthesis( B )" A e ro b ic r es pi ra ti on(C ) M eiosis(D) Ni tr og en f ix at io n(E) Endocytosis .

49. C ertain m etabolic pathw ays are affected by thebuildup of a product w hich interacts w ith anenzym e catalyzing one of th e initial steps of thep ath wa y; th is can be an example of(A) tra nsc rip tio nal reg ulatio n "(B) thermodynamic regulation"(C) t ra n sl at ional r egu la ti on(0) feedback inhibition(E)" post tr an sl at ional mod if ic a ti on

48 , T he control of breathing is centered in w hichof the follow ing areas of the b rain '}(A ) An t er io rp it ui ta ry(B) Corpus callosum(C) Cerebellum(D) Medul la o b lo ng a ta(E) C e r e b r u m

50. A ll of the fo llo w in g s ta teme nts a bo ut n eu ro tra ns -m in er s a re g en era lly t rue-EXCaPT:" (A ) T hey may c au se d ep olariza tio n o r

h yp erp ola riz atio n o f th e p os ts yn ap ticmembrane." ( B) T hey are actively transported across thes yn ap tic c le ft.(C) T hey are release d fro m m em bra ne-b ou ndpackets called vesicles." "

(D ) T hey may be enzym atically deg raded at thep os ts yn ap ti c membr an e.(E ) T hey bind to specific receptors on thep os ts yn ap ti c membr an e.

8 2 00 2 AP B io lo gy Rel ea se d E X a m Excerpt


9/18

IiII1i

' # i ; " " "5L A customer observed that a particular potted plant

in a re sta ur an t wa s bigger an d greener than otherplants in the room. When asked, the owner saidthat he poured leftover club soda (carbonatedwater) into that plant's pot every day. Which ofthe fol lowing bes t explains how th e club .sod aaffected that plant's growth?(A) The basic pH of the dub soda caused the

plant to grow rapidly ..(B) The temperature of the club soda promoted

faster growth.(C) Oxygen bubbles from the club.soda oxygen-

ated the soil.(0) The roots absorbed the CO2 necessary for.

. photosynthesis.(E) The roots received more moisture, and the

leaves were exposed to more CO2,)52. A major function of the Casparian strip of theendodermal cells of a root is to

(A) protect the meristem as the root tip grows.through t h e abrasive soil particles(B) allow for expansion of the vascular cambiumas the root grows laterally .(C) control the movement of materials into the

vascular cylinder of the root' .(D) initiate lateral root growth(E) .serve as a site for the storage of excess sugarsin the form of starch

53. Which of the following is correct concerning .a spherical cell?(A) As th e diameter decreases, the surface arearemains the same.(B) As the 'diameter decreases, .the' surface area

increases.(C) As the diameter decreases, the surface-to-volume ratio increases.(0) As the diameter increases. the volumedecreases. .

(E) The surface-to-volume ratio is'independentof the diameter.54. Which of th e following directly produces th e mostATP per mole of glucose during aerobic cellular

respiration? .(A) Glycolysis(B) Electron transport chain and ehemiosmosis(C) Substrate-level phosphorylation .(D) Kreb's cycle(E) Alcoholic fennentation

55. All of the following could reduce the yield ofphotosynthetic products ~~CEPT.(A) lower concentrations ofcai:bon dioxide in theatmosphere(B) increased photorespiration(C) reduced carbon dioxide concentrations in theair spaces of the leaf . .(D) increased frequency of stomatal, openings(E) fewer Calvin cycle enzym es .

2002 AP B iol ogy Re le as ed Ex a m Excerpt 9 .


10/18

"

:~~ lmh.)~6. Which of the following is true about theproduction of polar bodies in humans'!

(A) Itincreases genetic variability.(B) It provides the maximum amount ofcytoplasm and resources to the ovum.(C) It OCcurs in male and female vertebratesduring meiosis I.(D) It is completed prior to fertilization.(E) It results innondisjunction.

59. All of the following ar e common to


11/18

- . t w n . h ' .Directions: Each group of questions below consists of five lettered headings followed by a list of numbered phrasesor sentences. For each numbered phrase or sentence, select the one heading to which it is most closely related andfill in the corresponding oval on the answer sheet. Each heading may be used once, more than once, or not at allin each group ..Questions 62-65 refer to the following enzymes.

(A) DNA ligase(B) DNA polymerase(C) RNA polymerase(D) Restriction enzyme(E) Reverse transcriptase

62: Enzyme used in the synthesis ofmRNA63. Enzyme used during replication to attach Okazaki

fragments to each other64. Enzyme found in retroviruses that produce DNAfrom an RNA template65. Enzyme used to position nucleotides during DNA'replication .

Questions 66-69 refer to the probabilities below.Assume that the alleles referred to all assort

independently _(A) 0(B ) 1116(C) 114(D) 1/2(E). 31 4

66. Probability that the genotype Aa will be producedby the parents Aa x Aa

67. Probability that the genotype ccdd will beproduced by the parents CcDd x CcDd

68. Probability that the genotype Rr will be producedby the parents Rrx rr

69. P ro bability that the genotype ITSs will b eproduced by the parents 1TSs x TtSS

. 2 0 02 AP . B io lo gy R ele as ed Exam Excerpt 11.


12/18

Questions 70-73 refer to the following groupS o f blological compounds.(A) Proteins(B) Carbohydrates(C) Nucleic acids(D) Lipids(E) Steroids

7 0. S yn th esiz ed a t the ribosome71. Includes glycogen, chitin. cellulose. and glucose72. Used for insulation and buoyancy in marine Arctic animals

73.:Used to carry the genetic code

Questions 74-77 refer to the following.(A) Echinoderms(B). Annelids(C) A rthropods .(D).Cnidarians (coelenterates)(E) Chordates .

74. These organismsoften have both a polyp forman d a m ed usa fo rm int he ir l if e cycl e.

l i 7 5. T he se o rg an ism s b av e p hary ng eal g ill slits a nd ad orsa l h ollow n erv e c ord a t some time i n t he irdevelopment.

76. T h es e o rg an isms hav e r ad ia l s ymme tr y and awater vascu la r system a nd a re g en er ally b ottom -dwellers.

~: .

7 7. T hese o rg anism s h av e a chitinous exoskeleton andjointed appendages .

,.

i2 00 2 A P B io lo gy R ele as ed E xam E xcerp t ..2


13/18

I

iI

!i

l iMit.hl'Q uestions 78 -8 1 refer to mole cu le s o f t he follo win gsubstances.

(A) Cytochrome(B) FADH1(C) NAD+(D) NADP+(E) Ox .y ge n (0 ,)

78. A memb ra ne -b ou nd e le ctro n carrier found in the electront ra nspo rt s ys tems of both a er ob ic r es pir atio n a ndphotosynthesis .

7 9. C o en zym e that tra nsfe rs e le ctro ns from th e Krebs cycle to themitochondrial electron-transport chain at a lower energy levelthanthat of electrons. entering at the beginning of the chain S O . An intermediate electron acceptor for oxidations that occur inboth glycolysis and in Krebs cycle r eactions .81. The final electron acceptor for cellular respiration

: 2 00 2 AP B io lo gy R ele as ed Ex am Excerpt~.;. ,


14/18

l i M i t " ' "Questions Sz,,86 refer to the follawing diagram of a plantcell,

(C)

(A) ---ff-ll(B) ---'---H+'-

(D)

(E)

.

.;.i;

82. Site of glucose synthesis83. Site of conversion of-chemical energy of glucose

toATP

85. Site of transport of materials into and Out of thecell86. Evolved from a photoautotrophic prokaryote

84. 'Site of modification and packaging of proteinsand lipids prior to export from th e cell.

!..

14 . 2 00 2 A P B io lo gy R ele as ed Exam E xcerpt ..~'.-", .


15/18

.~.~ .~ .:~

a;

(mit'JII'Directions: Each group of questions below. concerns an experimental or laboratory situation or data. Ineach case,first study the description of the situation or data. Then choose the one best answer to each question following it andfill in the corresponding oval on the answer sheet.Questions 87w89 refer to the following dichotomous key.

. . . (+) .. -CGoUPAExternal. C + ) Skeletonr-----Segmentation Group BC (-) (-), - . . , o U . Group C+ VJ-Coelom

'---- .... Symmetry

81. Centipedes and millipedes should NOT be placedin group B becausethey .(A) have an exoskeleton(B) display radial symmetry(C) . lack a coelom(D). are unsegmented(E) have an endoskeleton

88. Which of the following phyla is represented bygroup E1(A) Mollusca(B) Cnidaria (Coelenerata). .(C) Porifera(D) Chordata(E) Annelida

I ~ GroupD(+)(-).'-_- GroupE89. Clam, octopus, and oyster are classified in whichgroup?

(A) A(13) B(C) c(D) D(E) E

20Q .2AP B io lo gy Rel ea se dEx am Exce rp t 15...- '.'.~


16/18

i l : ".:1: \' f !'1 ' .:~;;:i -,i,.!:~ .: .;:i:~. :.

Ir

l n u t . u . ,Questions 90-92 are based on the following.

In the 1940's, Avery, MacCleod, and McCarty transformed nonencaps ul ate d b ac te ria into encapsulatedforms by growing the n on en ca ps ula te d c ells in a culture containing a n extract mad e from d ead en cap su la ted cells.The transformed cells produced colonies of e nc ap su la te d b ac te ria . T h re e different procedures and their results areoutlined below.Procedure I:

Extract made from d ea d encapsulated cells added to culture medium.Nonencapsulated bacteria added to cu ltu re m ed iu m.Results: Both nonencapsulated and encapsulated bacteria grow.

Procedure II:

Extract made from dead encapsulated ce ll s t rea ted with protein-degrading e nzyme s b efo re a dd in g extract toculture medium.. Nonencapsulated bacteria added to culture mediumR esults: B oth nonencapsulated and encapsulated bacteria grow.

Procedure III:Extract made Q : o I D dead-encapsulated cells treated with DNAse (an enzyme that selectively "destroysDNA)be fo re ' adding extract to culture medium. -Nonencapsulated bacteria added to culture medium.Results: Only nonencapsulated bacteria grow.

90. A reasonable conclusion to dr aw from th e resultsof the experiment is that(A) DNA is the genetic material(B) DNA replication is semiconservativeCC) DNA is a double helixC D) D NA is translated into protein(E) mutation is a change in the genetic material

92. What was the purpose of treating the extract withDNA se in P rocedure III. ? .(A) To remove the encapsulated bacteria from thextract'(B) To serve as a positive control by demon-strating that a protein "inthe extractis the

transforming factor .(C) To serve as a.negative control by demon-strating that transformation does no t occurwithout DNA(D) To destroy enzymes in the extract(E) To destroy any capsules that might be in theextract

91. What was the purpose of treating the extract withprotein-degrading enzymes in Procedure II ?(A) To demonstrate that the tra ns fo rm ing f ac to r isanenzyme . ..(B) To demonstrate that the transforming factor is'

not a protein(C) Todestroy nucleic acids in the extract(D) T o destroy any capsules in the extract(E) To prevent the extract from beingcontaminated by nonencapsulated bacteria

16 2002 ~ B iology R eleased Exam Exc-etP,t.


17/18

.Im u . " "Questions 93-96

A scientist determined the rate of an enzyme-catalyzed reaction by measuring th e amount of product formed overtime. The following curve was generated from the data.collected.

12345 6Time (minutes)

93. Based solely o n the curve, what can-be saidconcerning the calculated reaction rates at1minute and at 2 minutes?(A) The rate after 2 minutes is greater than therate after 1minute.(B) The rates are the same at 1 minute and at

2minutes.(C) The rates are affected by high concentrationsof inhibitors. . . .. - C D ) The rates are both zero.(E) The greater the rate, the faster the enzyme is

denatured. .

95. What is the most likely explanation for the changei.nthe slope of the line between 3 and 5 minutes?(A) The enzyme had denatured.(B) The enzyme had achieved its maximumvelocity.(C) A large amount of the substrate had beenconsumed,(D) An allosteric inhibitor appeared.(E) There was a dramatic change inthe pH.

9 6: D ur in g w hich time interval is the reaction ratelowest? .

94. The rate of th e reaction could also bedete,nitined by'. .(A) measuringthe change i~the amount of

.enzyme _. .. .. (B) 'measuring the change in th e amount ofsubstrate(C) measuring the .change in salt concentration"(D)"adding more substrate . -

( 1 3 ) adding more e nz yme

(A) 0-1 minute(B) 1-2minutes(C) 2-3 minutes(D) 3-4 minutes

. (E) 4-5 minutes

-

.' .

2 00 2 A P B iolog y Released Exam Excerpt. . 17~.~. ,


18/18

.

:

Questions 97-100 are based on the following.I t l h i . 1 I . ,

Therate of transpiration, the flow of water through the stem, and leaf water potential are measured in . a treeduring a 24-hour period under normal environmental conditions. The results from these measurements are shown inthe graphs below.

Graph I

Graph II- a':;15" 0 -5A.. -c .B _ g -10~ '-' .,-15] . '0 2 4 6 8 10

o 2

o

-- Transpiration--.:.-- Stem Flow

10AM. Noon

Time of DayP.M.

.2 4 6 8 10A . M . Noon

Tune of DayP .M . .

97. Based on graphs I and I I 7 which of the follow-ing is the best conclusion that can be reached'].. ' (A) Decreases in leaf water potential are caused. b y increased transpiration.,. .

(3) The increasedrate of transpiration Increasesl e a r water potential.(C) The flow of water through the stem has noeffect o n leaf water potential.,(0) Leaf stomata are closed at 10 A.M.(E) Water is most likely.to flow into the leaf. at4 A.M. .

99. What can be deduced from graph I ?(A) The rate of transpiration. is constant through-out this 24-hour period. . .(B) There is no correlation betweenthe rate oftranspiration and the flow of water throughthe stem. . . . .(C) The maximal flow of water through the stem

lags behind th e maximal r at e o f t ransp ir at ion(Dj.The rate of transpiration never reaches zero .(E) At noon, the rate of transpiration exceeds therate of water f low t hr ou g h- a stem. .

98. In this experiment, water flow' up the stem couldbe measured in which of the following structures"!'(A) Phloem(B) Xylem(C) Lenticels(0) Stomata(E) Casparian strip

100. All of the following changes would be likelyto decrease the rate of transpiration at 8 A.M .EXCEPT(A) causing the stomata to close(B) increasing 'the humidity of the atmosphere(C) increasing the water potential of the. .atmospbere(D) increasing the water potential of the soil(E) placing the plant in total darkness

2002 released exam

Documents