CONFIDENTIAL *

JABATAA :GERISEMBILAN JA WBILAN JABATAA 96411 'GERISEMBILAN JA S TPM 2009 ITBILAN JABATAA :GERISEMBILAN JA WBILAN JABATAf\.. ~'-' ov ... " ..... ~·GERISEMBILAN JAw .. I .... ~'-' 'VI .. " ..... ~~~, ,,~~.IIBILAN JABA TANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN

. JABA TANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGERISEMBILAN JABATANPELAJARANf'v BIOLOGY -AJARANNEGERISEMBILAN JABA TANPELAJARANN .AJARANNEGERISEMBILAN JABATANPELAJARANf'v- __ ... __ ... _ ._ ... . _ .. - . .. .... __ AJARANNEGERISEMBILAN JABATANPEL A.IARANNr::r.:;FRI.~ r::MRII AN .IARATANPFI A.IARANNEGERISEMBILAN JABA TANPEL Paper 1 EGERISEMBILAN JABATANPEL . EGERISEMBILAN JABATANPEiJ-IJt-IrV·..,VIVC\JC/\10C1VIDILJ1IV JrlDrll rlIVrCLrlJrI/\t-IIVlvEGERISEMBILAN JABA TANPELAJARANNEGERI.~ ~· .~.. ... .• ~ • ~ ANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERf. (1 % hours) -ANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERI. . -ANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TA NPELAJA RANNEGERISEMBILAN

JABATAN PELAJARAN NEGERl SEMBILAN PERCUBAAN BERSAMA

SIJIL TINGGI PERSEKOLAHAN MALAYSIA 2009

Instructions to candidates:

DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO

There are fifty questions in this paper. For each question, Jour suggested answers are given. Choose one correct answer and indicate it on the multi-choice answer sheet provided.

Read the instructions on the multiple-choice ans'rjler sheet very careJully.

Answer alJ questions. Marks will not be deductedJor wrong answers.

This question paper consists of 16 printed pages

STPM TRIAL 964/1 CONFIDENTIAL *

papercollection

CONFID ENTI AL* 2

I. "Vhi ch of the follovving are th e properti es of water?

A

B

C

D

Specific heat capacity

Hi gh

Low

Hi gh

Low

Latent heat of Surface vapo uri sation tension

Hi gh High

Low High

High Low

High Low

2. Diagram belO\v shows a type of monosaccharide.

OH

Which of the foll owin g pol ymers can be formed from the condensation of the molec ul e shown in the diagram above?

Glycogen II Amylose 111 Amylopectin IV Starch

A II and III B I, II and III C II , III and IV D J, 11 , III and IV

3. A mitochondrion in (I mammalian musc le cell measures 1.2 f-lm. In the electron micrograph, the length of the organelle is 48 mm. What is the magnification of the electron micrograph ?

964/1

A 40000 X B 12000 X C 4400 X D 4000 X

*This question paper is CONFIDENTIAL until the examination is over CONFIDENTIAL*

papercollection

C:ONF IDENTI AL* 3

4. Which of the following structures of membran e bound organelles is correctly matched with its function?

A

B

C

D

Structure

An ex tens ive network of tubes; each tube is bound by a single menlbrane . . A stack of elongated, curved sacs; each sac is bound by a single membrane.

A spheri ca l sac bound by a single membrane.

A sac bound by two membranes, the inner is hi ghl y folcled.

Function

Lipid synthesis

Photosynthesis

Protein synthesis

Packaging of proteins

s. The graph below shows the rate of reaction with and without an inhibitor.

Rate of reaction

Concentration of substrate

Which of the following is true regarding the above graph?

Curve J Curve 2

A Competiti ve inhibi tor Non-competitive inhibitor

Curve 3

Normal activity

.

B Competiti ve inhibitor Normal activity Non-competitive inhibitor

c Non-competitive inhibitor Competitive inhibitor Normal activity

D Normal activity Compet it ive inhibitor Non-competitive inhibitor

964/ 1 *This question paper is CONFIDENTIAL until the examination is over CONF1DENTIAL*

papercollection

CONF IDEN']'IAL* 4

6. The table below shows amin o acids and their base sequence on the mRNA codon.

Amino ac id Base sequence on the mRNA codon, Valine GUC Glycine GGU Methionine AUA

What is the base sequence on pnrt of a DNA strand, which would code for the tripeptide va l ine-m eth ion i ne-gl yc ine?

A GUC AUA GGU B GTC ATA GGA

C CAG TAT CCA D TAT CAG CCA

7. Diagram below shows the electron pathwny in cyc lic and non-cyclic photophosphorylation during the li ght reacti on stage in photosynthes is.

964/1

energy

level

ferrodoxin

quinone II i ~ ;.,. 1\ 8\1 y . X ~DP ' -+NADPH

~ 2e - / e- Z

2e-- \ 2H I + 2e -- T I mOlepcule

I "\ I /"-" O2 released

(PS 1\ ",---;J

~~0 +-------------~

Which of the followin g statements are true for electron pathway in the above diagram?

Th e electrons in PSI and PS II nre exc itecl to hi gher energy leve ls II NADP+ is red uced in non-cyc li c photophosphorylation III ATP is produced in steps Y and Z IV Molecule P is a water molec ul e

A I and II onl y B II and IV only

C I, II and III only D I, II , III and IV

*This question paper is CONFIDENTIAL until the examination is over CONFIDENTIAL *

papercollection

CONF ID ENTIAL ';' 5

8. The grap h belo'w shows th e relati onship between the rate of photosynthesis with environmental factor X.

rate of photosynthesis

(arbitrary unit)

t

Which of the fo llow ing is factor X?

I Light intensity II Oxygen concentrati on III Temperature IV Carbon dioxide concentrat ion

A I and IV onl y B II and III onl y C " and IV onl y D I, III and IV on ly

Factor X

9. Which products are formed during anaerob ic respiration?

Musc les Yeast cells A Pyruvate, NAO+, ATP Ethanol, NAD+, ATP B Lactate, NAO+, A TP Ethanol, NAO+, ATP, CO2

C Lactate, NAD-", ATP, CO2 Ethanol, NAO+, ATP D Ethanol , NADH , ADP, CO2 Lactate, NADH, ADP, CO2

96411 *Thi s question paper is CONFIDENTIAL until th e examination is over CONFlDENTIAL *

papercollection

CONFIDENTIAL* 6

10. Diagram below shows a reaction in Krebs cycle.

What is process X?

A Chemiosmosis

Krebs cycle

GTP

AD~GDP ATP

C Photophosphorylation B Oxidative Phosphorylation D Substrate level phosphorylation

11. Which of the following organism is/are not saprophytes?

Afucor II RhizopZls III Taenia IV Amoeba

A I only B II and III only

C III and IV only D I, III and IV only

12. Which of the following sequences brings about Bohr's effect?

964/1

I I-t causes oxyhaemoglobin to release its oxygen II CO2 enters red blood cell III Carbonic anhydrase catalyses the formation of 1-1 2C03

IV Respiration of tissues gives out CO2

A I, III, IV and II B II , Ill , I and IV

C IV, III , II and I o IV, II , III and I

*This question paper is CONFIDENTIAL until the examination is over CONFlD ENTlAL*

papercollection

CONF1DENT I AL '~ 7

13. Which of the fo ll owing exp bins why myog lobin IS foun ci III large amounts III the mu sc les of birds?

A Myoglob in ca n ') Ll ppl )' thc encrgy needed for nyin g B Myoglob in can supp ly oxygen to th e Illll scul ar ti ssues when birds fl y in areas with low

parti al pressure of oxyge n. e When compared to haemoglob in , myoglobin has higher affinit y toward s oxygen ane! can better

retain oxygen in acti ve mu sc les . D Myog lobin has a small er Ill olecul ar s ize cO ~ ~ l p!"ed to h3emcglob in .

14. Which process does not occur durin g th e opening of stomata?

A Suga r is converted into starch. B Starch is converted into Ill a li c ac id . e Water enters into guard cell s by osmosis. D Potass iulll ions diffuse into guard ce ll from adj acent cell s.

15. Which of the foll owing increases the rate of im pul se released from sinoatri al node?

964/ 1

I Impulse from the sympatheti c nerve Il Impul se from the parasympatheti c nerve III Thyrox ine hormone IV Adrenaline hormone

A I and IV B II and IV

e I, I II andl V D II , lIl andl V

*This question paper is CONFIDENTI AL until the examinati on is over CONFlDENTI AL*

papercollection

CONFID ENTIA L* 8

16. Diagram belo\-\' sho'vvs a i'vlull ch model.

x

Pure water

~.

Semipermeable membrane

If A is fill ed with concentrated sucrose so lution, while B is fill ed \vith dilute sucrose so lution, which of tile foll ow ing statements are true?

1 A is eq uivalen t to leaves in translocat ion . II Hi gh turgor pressure is created in A. III X is analogoLls to phloem in plants. IV Y is analogous to xy lem vessels in plants.

A 1, II and III B 1, II and IV

C I, III and IV D I, II, 11I and IV

17. What is tile function of ad renaline in the negative feedback mechanism ifbody temperature of endotherms decreases?

A Stimulate secret ion of sweat B Increase convers ion of glycogen into glucose in li ver C Triggers a shiverin g process D Contract erector mu sc les

18. Liver is an organ in vo lved in homeostasis because it

964/1

I produces bile sa lt II performs gluconeogenesis III performs detoxi fi cati on IV produces a hi gh amount of heat

A III and IV B I, III and IV C II , III and IV D I, II, III and IV

*This question paper is CONFIDENTIAL until the exam ination is over CONFIDENTIAL*

papercollection

CON FIDENTIAL* 9

19. Which of the foll owin g are the characteri sti cs of an impul se?

I It foll ows the a ll or nothing law II Speed of impulse transmiss ion is faster in mye linated axon III Speed of impul se transmi ss ion is fas ter in unm ye linated axon 'with a smaller diam eter IV In the abso lute re fractory peri od, a new impul se cannot be generated even if a strong

stimulus is rece ived

A L II and !II B I, IlandlV C I, III and IV D I, II , III and IV

20. Curare effects neurolllLl scul ar juncti on by

A binding to receptors on postsynap tic membrane B preventing exocytosis of acetylcholine into the synaptic cleft C preventing action of cholinesterase D preventing di ffu sion of calcium ions into presynaptic membrane

21. The follovvings are the events that occur in the act ion of a steroid based hormone.

I Hormone-receptor complex diffuse into the nucleus II Steroid based hormone diffuse into the ce ll through the cell membrane III Hormone bind s to the receptor in the cytoplasm IV Specific gene is activated in DNA

The correct sequence for the events above is

A I, II , Ill, IV B I, Ill , II , IV CII , III , I, [V )) II , [, [II , IV

22 . Ifplant X is a short day pl ant with a critical day length of8 1/2 hours, in which of these conditions will plant X not flower'?

964/1

Exposed to red li ght for 9 hours II Kept in darkness for 8 hours III Exposed to far red I ight for 12 hours IV Kept in darkness for IS hours before ex posed to red li ght for I hour

A I and II B III and IV C I, II and IV D II , III and IV

*This question paper is CONFIDENTIAL until the examination is over CONFIDENTIAL *

papercollection

CONF I DENTIAL* 10

23. Which of the followings are invol ved in ce ll-med iated response of the il11rnune system?

I involves B lymphocytes II mature T lymphocytes req uire macrophages to prese nt the anti gen for them to bind III in vo lves the th ymus gland IV mat ure lymphocytes can directly bind with ant igens.

A I and IV B II and 11I C I and 11I D II and IV

24. HIV lies dormant in the body because

A its reverse transcriptase is engulfed by T4 cell B its particle rest in the cytoplasm ofT4 cell C the replication of its RNA occurs later D its DNA is incorporated into the DNA ofT4 ce lI

25. The sporangium of Marchantia where spores are pl:oduced is a

A diploid structure B haploid structure C dioecious structure D oviparous structure

26. Which orthe fo ll ow ing terms app ly to birds?

ov iduct II vIvIparous III internal fertilisation I V hermaphrod ites

A II and III B I and III C III and IV D II and IV

27. In an amniotic egg of a bird, the rese rvo ir fo r waste and the part th at provides for gas diffusion is the

964/]

A chorion B yo lk C amnIon o allc1lltois

*This question paper is CONFIDENTIAL until the exan1in ation is over CONFIDENTIAL'"

papercollection

CONfIDENTIAU' II

28.

The formation 01-blastul a frolll n zygo te in vo lves C\ success iOI1 of" rnp id ce ll divi sion s. Thi s speciall ype orcell di vision creates Clill uiti ce llular embryo

The above statement refers to whi ch stage of embryo lli c deve lopment?

A Blastomere B Cleavage C Gastrul ation D Organogenesi s

29. The hormone that plays an important role in seed germ inati on and ea rl y seeeling growth is

A auxll1 B gibberelin C cytok inin D absc isic acid

30. The tab le below shows four patterns of growth curves and their exampl es.

Growth pattern Examples (a) Isometric grov·"th I (i) 1-lulll an organs (b) Allometric growth (i i) Coral ree fs (c) Intermittent growth (iii ) fi sh (eI) unli mited growth (iv) Grasshopper

Which of the fo llow ing is correct ly p~lired ?

-

(a) (b) (c) (d)

A (i) (i i i) (iv) (ii) B (i i) (i i i) (i \') (i) C (i ii) (i) (i i) (iv) D (iii) (i) (iv) (i i)

96411

!

*This question paper is CONfIDENTIAL un til the exam ination is over CONFIDENTIAL*

papercollection

CONFIDENTIA L * 12

3 1. Which of the fol low in g statements me tru e ilbout neurosec reti on secreted by the neurosecretory ce ll in in sects?

I It is stored in corpus carel iac ull1 II It inhibi ts th e effect of juveni le hormon e III It is also known as prothoraci ctrop hi c hormone IV It st imul ates the secretion of ecdysone from prothoracic hormone

A I, II and III B I, III and IV

C II , III and IV D I,II , lll and lV

32. In pea plants, red flovvers (R) are dominant to white fl owers (r) and ta ll (T) to shOl1 (t). The table shows the gametes and poss ibl e offspr ings of a dih ybrid cross . The numbers 1- 16 represent the genotypes of each ind ividuaJ.

RT Rt rT I't

RT I 2 3 4 Rt 5 6 7 8 rT 9 iO II 12 rt 13 14 15 16

If plants 4 and 13 are crossed , what proportion of th eir offsprin g \;vi ll show at least one recessive trait?

A 1/16 B 611 .6 C 7/ 16 o 9116

33. The colour of onions is controlled by two pairs of all eles Ss and Rr, which segregate independently. The a ll e le S is dOlninant anci 1l1ust be present to all ow development of pigment in the sk in . In its absence, the on ion is wh ite. All ele R is dDmin ant ond gives a red co lour, the recessive r gives a ye llow co lou i-. Y\ hat wi ll be th e rat io of phenotypes in the offspring of a cross between plants of genotypes SSR,R and ss r!"!

I white 3 red J wh ite A B

1 red I red I ye ll ow

C D I white : 2 red I yellow

34. Which of the following statement's are not tru e abo ut mutation s?

96411

mutat ions are spontaneous changes in th e amount or stru ctu re of DNA Or changes in the sequence of Ilucleoti de bases of a gene.

II the changes that occurred are non-random III all mutations lead to prod uction of non -functi ona l proteins IV ge rm-line mutations can be -inherited

A I and III B I and IV

C II and III o II and I V

*This question paper is CONFID ENTIAL until the examin ation is over CONFIDENTIAL'"

papercollection

CONF IDENTIAL* 13

35. Chromoso mal deleti on occurs

A when the deleted DNA segment becomes rea ttached in an in ve rt ed position. B when the chromClsome breaks and a segment of it is lost C when a segment of a chromoso me contai nin g a sequence of lltl cleoticles is repeated. D when the chromosome segment becomes deleted and rejoins at a different pos iti on on the

same chromosome or another non-h omol ogous chromosome.

36. The Hardy-Weinberg eq uati on does not app ly if

I there is migration II there is natural selection. III mutations occur. IV there is non-random matin g. V there is a large population .

A I, II , III and IV B I, II , III and V C I, Ill , IV and V D II , III , IV and V

37. The maintenance of the allele for sickl e-ce ll anaemia in human populations in malar ia-endemic region in Africa is an example of

A genetic drift B gene flow C founder effect D heterozygote advan tage

38. What is the function of the inducer of the lac operon?

A Bind to the promoter and prevent s the repressor from bindij! g to the operator. B Bind to the operator and prevents the repressor from binding to the promoter. C Binds to the repressor and prevents it from bi nd i ng to th e' PI:Oll1oter. D Binds to the repressor and prevents it from bindin g to the operator.

39. The statements below refer to different stages in the production of human insulin by genet ic engineering techniques. What is the correct sequence productio-il?

964/ 1

I DNA cut "vith restriction enzymes. II mRNA extracted frolll pancreati c cell s III Plasmid DNA and human DNA joined usin g li gase enzymes. IV DNA copy made using reverse transcriptase V Recombinant plasmid incorporated into bacteri al ce ll.

A I, Ill , IV, II , V B II, IV, III , V, I

C II , IV, I, Ill , V D II , I, IV, Ill , V

*This question paper is CONFIDENTI AL until the examinat ion is over CONF IDENTIAL*

papercollection

CONFIDENTIAL* 14

40. Which of the following are characteristics of pl asmid?

Found in the bacteria II Integral par! of bacterial chromosome III Confers special characteristics to the organism IV Self-replicating V Small, linear molecule

A I, ll, III and I V B I, III, IV and V C I, III and IV D III , IV, and V

4 J. The following are uses of recombinant DNA technology except

A screening for carriers of genetic diseases B identification of badly-decomposed victims C treatment of diabetic patients with synthetic insulin o prevention of inheritance of genetic disorder by offsprin g

42 . The table bdO\v shows the taxonomic groups and taxa for the house ny.

I 11 III JV

Taxonomic group Kingdom Phylum Class Order

Taxon (a) Arthropoda (b) Insecta (c) AnimaIia (d) Diptera

Which of the following combinations is correct?

A B C D

I Xc) (c) (e) (c)

11 (a) (b) (d) (a)

III (b) (a) (a) (d)

43. Which of the following is likely to be radially symmetrical?

A A chordate C An arthropod 13 A cnidarian D An annelid

964/1 *This question paper is CONFIDENTIAL until the examination is over

IV (d) (d) (b) (b)

CONFIDENTIAL*

papercollection

CONF ID ENTIAL* I S

44. Which of the fo ll owing statements are tru e about Marchanlia?

I Monoecious II Asexual reprod ucti on th ro ugh gemma cups III Gametophyte is dominant IV gametophyte is dependent on sporophyte

A I and II B I and III C II and III D 11 and IV

45. Which of th e follow ing cannot cause the geneti c vari ation?

I Mutati on II Camouflage 1II Recombination IV Dominancy

A II and III B III and IV C I and III D II and IV

46. Which one of these is the definiti on fo r the.:biogeochemi ca l cycle?

A Circulation of chemi cal elements th ro ugh the bioti c componen t of an ecosystem. B Circul ation of chemical elements th rougil the ab ioti c componen t of an ecosystem. C Circulation of chemica l elements through the biotic and ab iotic component of an ecosystem. D Circulation of organi c molecules through the bioti c components of an ecosystem.

47. The main reservo ir of phosphate is

964/ 1

A inorgani c phosphate ions in soil. B inorganic phosphate in rocks C inorgani c phosphate in organisms. D Organic phosphate in organi sms.

*This question paper is CON FIDENTIAL until the examination is over CON FIDENTIA L *

papercollection

CONFIDENTI AL* 16

48. The success of organisms in the ecosystem can be shown by th e

1 population di stribution Il population si ze III prey-predator relati onship IV position of trophi c level in the ecosystem.

A I and II B I and III eland IV D II and III

49. A quadrate with a measurement of SO cm x SO cm is L1 sed to ascertain the density of a type of herbaceous plant in a farmin g area. The bar chart below shO\vs the results of the experiment.

10

9

8

7

Number 6 of plant 5

4

3

2

o 2 3 4 5 6 7 8 9 10

Quadrat number

From the bar above, the density of th e herb8ceous plants per square metre or farm is

A 16 B 20 C 80 D 160

SO. Which of the following statement is not true about cmrying capac ity?

964/1

A Total number of organisms that can be support ed by enviro nmental resources . B Carrying capacity is limited by limited resources . C Carrying capacity of an ecosystem is constant. D Affected by environmental conditions.

END OF QUESTION PAPER

*This question paper is CONFIDENTIAL until the examination is over CONFIDENTIAL*

papercollection

CONFIDENTIAL *

N arne: ....................•......••...•...... <:Iass: .....•.......•......••....•..•••....•.. .

JABATAfI JABATA/\ 964/2 JABATAfI

:GERISEMBILAN JA :GERISEMBILAN JA :GERISEMBILAN JA

STPM 2009 lAB/LAN ItBILAN IABILAN

JABATAI\ . ..... ~ WI .. " .. w. w ..... :GERISEMBILAN JALJI ,. I .... ..... ~ 'VI " " " •• w ..... """ ...... ",-, ...... AB/LAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGER/SEMBILAN JABA TANPELAJARANNEGERISEMB/LAN JABATANPELAJARANNEGER/SEMBILAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANf'v AJARANNEGERISEMB/LAN JABATANPELAJARANN BIOLOGY AJARANNEGERISEMBILAN JABATANPELAJARANf'v ___ . " __ "'_'_" __ .. _ ...... _. _-AJARANNEGERISEMBILAN JABATANPEL A.IARANNFr,FRISFMRII AN .IARATANPFI A.IARANNEGERISEMBILAN JABATANPEL Paper 2 EGERISEMBILAN JABATANPEL EGER/SEMB/LAN JABA TANPELMvl'1rv1IVIVc0cnluCIVIDILMIV vI'1DI'1II'1/VrCL.I'1vl'1rv1IVlvEGER/SEMBILAN JABA TANPELAJARANNEGERI,"""'· ..... II ••• • ...... "T" ANPELAJARANNEGERISEMB/LAN JABATANPELAJARANNEGERf. (2 ~ hours) -ANPELAJARANNEGERISEMBILAN JABA TA NPELA JA RA NNEGERI, ~NPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGER/ JABA TANPELAJARANNEGERISEMB/LAN

JABAT AN PELAJARAN NEGERl SEMBILAN PERCUBAAN BERSAMA

SIJIL TINGGI PERSEKOLAHAN MALAYSIA 2009

Instructions to candidates:

DO NOT OPEN TIDS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO.

Answer all questions in Section A. Write your answers in the spaces provided

Answer any four questions in Section B. Write your answers on your own test pad Begin each answer on a fresh sheet of paper. Answers should be illustrated by large and clearly labeled diagrams wherever suitable.

Arrange your answers in numerical order and tie the answer sheets to this question paper.

This question paper consists of 8 printed pages

For examiner's use

1

2

3

4

5

6

7

8

9

10

Total

STPM TRIAL 964/2 CONFIDENTIAL *

papercollection

CONFIDENTIAL 2

Section A [40 marks]

Answer all questions in this section.

I. In some plants, Dowering is induced by a critical photoperiod. Cocklebur (Xanthium strumarium) is a short-day plant. The photoperiodic response is controlled by a specific light-sensitive pigment.

(a) State what is meant by the terms:

(i) photoperiod

(ii) photoperiod ism

[2 marks]

(b )(i) Name the pigments responsible for photoperiodism and their interconvertible

fomls.

[2 marks]

(ii) With an aid of a diagram, explain the process involved III the interconversion betvveen the two fonns of the pigment.

[3 marks]

(c)(i) State what is meant by a short-day plant.

[1 mark]

CONFTDENTIAL

papercollection

CONFllmNTIAL 3

(ii ) Explain huw fl owering is controlled in short-day plant.

[2 marks]

2. Graph A shows the changes in dry mass (g) of the tuber, leaves and stems of a potato plant. Graph B shO\·vs four growth patterns of various parts of the human body plotted in percentage or size against time (in year).

"'" ::J u

'" . ~ (l) N

'U'j

a tV (» cd C <D ~ (l)

0...

Graph A

12

~ 10 <n <n

E1 B c:-o 6

4

2

o

Graph B 200%

180

160

140

120

100%

80

60

40

20

2

/

/

/

/

/

, , , , ,

Leaves:'

3 4 5

Time (weeks)

I

/

I

I

I

I

I \

6 7 8

\ Thymus gland \

\ \

"

O~-r~~~-r~~~~~~~-r~~ o 2 4 6 8 10 12 1 4 16 1 8 20

Time (years)

(a)(i) Explain the shape of the curve for the tuber of the potato plant.

[2 mark]

CONFIDENTIAL

papercollection

CONFIDENTIAL 4

(ii) E.\p la in the dec line of the dry mass of the tuber.

[2 marks]

(b) State the age at which the human reproductive organs are growing most rapidly.

[1 mark]

(c) Sta te the type of growth pattern shown in the human's organ growth curve.

Ex plain.

[2 marks]

(d)(i) Describe the growth of the human thymus gland.

[2 marks]

(ii ) Ex pl ain the importance of the human thymus gland?

[2 marks]

CONFIDENTIAL

papercollection

CONFIDENTIAL 5

3. An experiment to determine the distribution of plants in a study area was done by lls lng a sampling method. Each quadrat size is 1m x 1 m. The number of organisms from each plant species in each quadrat is shown in the table below.

r-.. - ---.-.~- .... _--- ------Quadrat 1 2 3 4 5 6 7 -_.£ 9 10 Tota l

-Mimosasp_ , - 5 - 10 5 2 3 9 - - 34

f----15 18 6 12 14 Imperata sp_ - - 9 15 15 104

(a) Name the sampling method used in th is experiment.

[ I markl

(b) By using the data given in the preceding table, calculate the:

(i) frequency of Mimosa sp_

[ I mark]

(ii) relative frequency of Mimosa sp.

[3 marks] (iii) density of Imperata sp.

[I mark 1

(iv) relative density of Imperata sp_

[3 marks]

CONFIDENTIAL

papercollection

CONFIDENTIAL 6

(c) Name another sa mplin g method that ca n be used to plot the distribution of pla nts in a s tud y a rea.

[1 mark]

(d) If a sample or so il was takc n from thi s study ficld , name a method to obtain the orga ni sms present in the soil.

[I mark]

4. The karyoty pe (M) below was obtained from a pcrson suffering from a certain

genetic di seases.

.. "' ..... ·IIIIU UUUH I I

2 4 6 7 8 9

!!~9UnU IIH~~aa 10 I I 12 D 14 15 16 17 18

~~oo~~8~§ 1; "; U" 19 20 2 I 22 X X X

(a) How many c hromosomes arc round in the somatic cell of this person.?

[I mark]

(b) Name the gene tic disorder cause by the chromosoma l abnormality as shown in

the Karyotype M.

[I mark]

CONFIDENTIAL

papercollection

CONFIDENTIAL 7

(c) Describe the chromosomal events which may cause this genetic disorder.

[4 marks]

(d) State two features which will be shown by a person with the karyotype M as shown above.

1 ......... ..... ...... .... ..................................................................... .

2 ...... .... .. . .. ........... .. .... ........ .. ........ . . . . ................... . ................... .

[2 marks]

CONFIDENTIAL

papercollection

CONFIDENTIAL

Secti on B [60 marks]

Answer OilY four questions /rom this section.

5. (a) Stale structural dil"fcrcnces between RNA and DNA. [3 marks]

(b) Disc uss huw lhe inl~)f"(11ation from DN!\' is used to fonn a correct sequence of

am in a acids in the pol ype ptide. [12 marks]

6. (a) Describe the properties or haemoglobin that make them efficient in transporting

oxygen.

(b) Expl a in how gaseous exchange takes place in the alveolar surface.

[6 marks]

[6 marks]

(c) Explain br iefly the effect of carbon monox ide on the etTiciency of human

h<1emog lo bin in the transporta tion of oxygen.

7. (a) Describe how the heal1 beat is initiated and how it is regulated.

(b) Describe the causes of atherosc lerosi s and state its effects.

[3 marks]

[10 marks]

[5 marks]

8. (a) With reference to a labe lled diagram, describe the structure of a sarcomere.

Exp lain what happen s to the myofibrils during contraction and relaxation of

musc le.

(b) Expla in the effect o f" cu rare on the contraction of skeletal muscle.

9. (a) Describe how Human Immunode ficiency Virus (HI V) causes Acquired

ImrnLlnode l~ c i e ncy Syndrome (A IDS) .

[10 marks]

[5 marks]

[8 marks]

(b) Desc rihe the dcve lupment of the ce ll-mediated response In human immunity

sys tem .

10. With the aid of graphs and suita hle examples, explain briefly:

(a ) Stab ilisi ng selection

(b) Directional selection

(c) Disruptive se lectio n

END OF QUESTION PAPER

[7 marks]

[15 marks]

CONFIDENTIAL

papercollection

ANSWER TRIAL EXAM BIOLOGY PAPER 1 2009

QUESTION 18 The answer given by teacher is II and IV.

NO ANSWER NO ANSWER 1 A 26 B 2 D 27 D 3 A 28 B 4 A 29 B 5 D 30 D 6 C 31 B 7 D 32 C 8 A 33 A 9 B 34 C 10 D 35 B 11 C 36 A 12 D 37 D 13 C 38 D 14 A 39 C 15 C 40 C 16 D 41 D 17 B 42 A 18 C 43 B 19 B 44 C 20 B 45 D 21 C 46 C 22 C 47 B 23 B 48 A 24 D 49 A 25 A 50 C

papercollection

PAPER 2 TRIAL STPM 2009 - SECTION B ANS\VER SCHEME

NO ANSWERS SUB- TOTAL TOTAL

Sea) Differences between RNA and DNA

RNA (Ribonucleic acid) DNA (Deoxyribon uclcic ~lcid)

Consi st of a single Consist of two po lynucl eotide polynucleotide strand. strands wh ich co i I around each

other to form a double he li x. 1

RN A molecul e is shorter. DNA molecul e is much longe r. 1

Contains the pentose sugar, Contains the pentose su gar, ribose. deoxyribose. 1

The n i~rogenou s bases are The nitrogenoLl s base are adenine, uracil , cytosine and adenine, th yrn i!le, cytos ine and 1

guanlll e' guanin e.

I i

I Present in the nucleus and Mai nly present in the cytoplasm. chromosomes in the nu cleus. 1

Small amount is present in th e mi tochondri a and ch loropl asts.

There are three main type of Onl y one type of DNA. RN A: 1

messenger RNA (mRNA), transfer RNA .( tRNA) , ribosomal RNA (rRNA),

Any 3 Max 3

(b) • Protein sy nthes is invo lves transcripti on of DNA, amino ac id

activati on and transl ation . 1 1

Transcription:

• The part of DNA (ci stron) which codes fo r the specific 1

polypeptides unwinds as the hydrogen bonds between the bases

are broken.

• The RN A polymerase attaches to the promoter site. 1

papercollection

• As the RNA polymerase moves along the template strand in the

5' ~ 3' directiori, the free nucleotides in the nucleoplasm pair

with the complementary bases in the exposed DNA template

strand.

1

• The nucleotides are linked together by phosphodiester bonds. The 1

process require energy from A TP.

• The mRNA passes through the nuclear pore into the cytoplasm and 1

binds to ribosome.

• The exposed regions of DNA are closed by hydrogen bonds

between the complementary bases

Amino acid activation

Any 4

• One end of the tRNA molecule present in the cytoplasm has three

bases called anticodon which are complementary to the mRNA

codon triplet.

• The other end (free 3' end) has triplet bases CCA for the

attachment ofa specific amino acid.

1

1

1

• Amino acids in the cytoplasm are attached to specific transfer 1

RNA molecules, using energy from A TP to form specific amino

acid - tRNA complexes.

• This is known as amino acid activation and is catalysed by enzyme

aminoacyl-tRNA synthetase

• The transfer RNA molecules then bring specific amino acids to the

ribosome

Any 3

Translation • The ribosome contains binding sites for mRNA and tRNA

molecules.

1

1

1

• Messenger RNA enters into the cytoplasm. The 5' end of mRNA 1

binds to the small ribosome subunit.

• A tRNA-amino acid complex with anticodon UAC and carrying 1

I Max 4

Max3

2

papercollection

6(a)

the amino acid methionine binds to the codon AUG (start codon)

on mRNA .

• The large ribosome subunit then binds to the small subunit to form 1 I

functional ribosome. I

• A second tRNA- acid complex with complementary anticodon 1

enters into site A.

• A peptide bond is formed between the two amlllo acids. The

condensation reaction IS catalysed by the enzyme peptidyl­

transferase.

• tRNA at site P is released from the ribosome into the cytoplasm

and ribosome moves one codon along mRNA.

• tRNA in the A site ribosome moves to P site.

• The translation process is repeated to form polypeptide chain until

the ribosome reaches the termination codon . (UAA, UAG and

UGA)

Any 4

TOTAL • has four haem groups to bind with four molecules of oxygen

forming oxyhaemoglobin

• very little oxygen is released when oxygen is transported

through the arteries

• can maintain a high (80%) saturation of oxygen because the

change in partial pressure of oxygen in the arteries is little

• releases the oxygen to the tissues for respiration where there is a

sharp drop of saturation of oxygen

• adapted not to deprive the tissues of sudden loss of oxygen

because further drop in partial pressure would cause a slow

release of oxygen

1

1

1

1

1

1

1

1

1

• releases more oxygen when there is a higher concentration of H+ 1

caused by higher carbon dioxide concentration to supply more

Max 4

15

3

papercollection

oxygen to the respiring tissues

• foetal haemoglobin has a higher affinity for oxygen which enable

it to get oxygen from the mother's blood

Any 6

(b) • air is drawn into the alveolus by the expansion of walls of the

lungs because of the negative pressure in the thoracic cavity

• changes take place in the blood due to the low concentration of

carbon dioxide in the air

• HCO)- ions enter the red blood cells , changed into H2COJ and

dissociate into water and carbon dioxide gas which diffuses into

alveolar spaces

• at the same time oxygen from the air di ssolves in the moisture

lining the inner surface of the alveolus

• then into the red blood cellsthrough the alveolar and capillary

wall

1

1

1

1

1

1

• in the red blood cells, oxygen molecules bind with the haem 1

group of the haemoglobin to form oxyhaemoglobin

• there is aiways a concentration gradient between the gas in the 1

blood and alveolar spaces by the rhythmic expansion and

contraction of the alveolar walls Any 6

(c) • carbon monoxide IS considered to be a dangerous respiratory 1

pOison

• it combines with haemoglobin more read i Iy than oxygen to form

cnrboxyhaemoglobin

• resulting in the inabil ity oC haemoglobin to take up oxygen

• decreasing the oxygen supply to the respIrIng tissues which

eventuall y stops the cellular respiration

TOTAL

1

1

1

Any 3

Max6

Max 6

Max 3

15

4

papercollection

7(a) Initiation of heart beat

• The heart walls consists of cardiac muscles which are myogenic,

that is, their rhythmic contractions arise from within the heart 1

mLiscles themselves.

• The regular heart beat depends on the two nodes present in the

heart. The first node is the sino-atrial node (SAN) which is 1

embedded in the wall of the right atrium close to the point where

the anterior vena cava enters the heart. The second node is the

atrio-ventricu lar node (A VN) which is embedded between the ,

right atrium and ri ght ventricle.

• SAN functions as a pacemaker. There is a potential difference 1

across the membranes of the cells of SAN. As sodium ions enter

the cells, they depolarise the SAN and produce a wave of

excitation .

• The wave of excitation that originates in the SAN spreads across 1

both atria. It causes both atria to contract simultaneoLisly. There is

a delay of about 0.1 s in the conduction of excitation from SAN to

the A VN, which means that the atrial systole is completed before

the ventricular systole begins.

• The A VN conducts the wave of excitation to the bundle of His and 1

its finer branches known as the Purkyne/Purkinje tissue which then

conduct to the apex and throughout the ventricular walls. The

ventricles contract simultaneously from the apex upwards,

squeezing blood out of the ventricles towards the aorta ancl

pulmonary artery. In this way, atrial systole can occur

rhythmically.

• Sodium ions are pumped out of the cells and this repolarises the • SAN. The atria are in a state of diastole. The whole process is then

1

/

repeated

Any 5 Max 5

5

papercollection

Regulation of heart beat

• Even though the rhythmic beating of the heart is initiated by the

pacemaker, its rate is regulated by the autonomic nervous system

which is divided into the sympathetic nervous system and

parasympathetic system. The sympathetic nerves, part of the

sympathetic nervous system, have their origin in the cardiac

acclerator centre of the medulla.

• Stimulation of these nerves causes a release of noradrenaline

which results in an increase in the heart rate. The vagus nerves,

part of the parasympathetic nervous system, originate in the

cardiac inhibitory centre of the medulla,

1

1

• Stimulation of the vagus nerves causes release of acetylcholine in 1

the SAN, A VN and the bundle of His. This reduces the heart rate

• At times of stress, adrenaline is secreted by the medulla of the 1

adrenal glands. Adrenaline increases the heart rate.

• An increase in the partial pressure of carbon dioxide (a drop in the

pH of blood) or the decrease of blood pressure increases the heart

rate.

Artherosclerosis

• The thickening and hardening of the arterial wall caused by the

deposition of lipids, e.g. cholesterol, triglycerides, fibres and

calcium deposits beneath the inner walls of arteries known as the

endothelium.

• The deposits formed a plague or atheroma. Continuous deposition

causes an increase in the size of the plague . . It protrudes into the

lumen, narrowing the lumen of the arteries and reduce the blood

flow.

1

1

1

• If the plague breaks through the smooth endothelium, its rough 1

surface causes a blood clot, called thrombus. If the thrombus

increase in size, it narrows or blocks the lumen and prevents the

5

6

papercollection

8(a)

blood flow (thrombosis occurs).

• Artherosclerosis often occurs in the arteries such as the aorta,

carotid arteries, iliac and coronary arteries.

Effects of artherosclerosis

• Artherosclerosis causes thrombosis and embolism.

• Reduced blood flow to the heart can damage the heart tissues; it

causes chest pain called angina pectoris or heart attack known as

myocardial infarction.

1

Any 3

1

1

• Reduced blood supply to the brain causes stroke. Narrowing of 1

arteries causes hypertension or high blood pressure Any 2

TOTAL

Dark band (A) Light band (I) ,~ __ ~A \~

--.-__ ~ __ [r-::::::~==:::::::;:==~M~m~embrane -Zmembrane

--..... ----.,...----t-- ThIck filament (myosin) -4-----4-__ .:--.... --~ __ -+-=_;....T..;...:.h,;;.;.ln.;...;.filamenl (actin)

\'--_-----~v_~---------I One sarcomere

• Diagram 1

Labels: 2

• H zone Yz

• dark band/fA band Yz Yz Yz Yz Yz Yz

Any 4

• I band//light band

• Actinl/thin filament

• Myosin//thick filament

• Z membrane//line

• M membrane/lline

Max3

Max2

15

Max 3

7

papercollection

• The sarcomere is the basic unit of the myofibril between two Z

lines. 1

• The myofibril is made up of thick filament/myosin and thin

fi lament/actin. I

I • The thick and thin filaments overlap to form the darker band.

• During muscle contraction the position of thick filament remains 1

unchanged.

• Thin filament slides past one another. 1

• Myofibril becomes shorter and shorter. I

• During muscle relaxation the position of thick filament remains

unchanged. 1

• The thin filament slides out to the original position. 1

• The muscle reverts to its original position. 1

Any 7 Max 7

(b) • Curare binds to the receptor on the postsynaptic membrane of I

the neuromuscular junction where acethylcholine is supposed to ,

bind.

• Depolarization on the postsynaptic membrane is prevented, and 1

• impulse transmission across the neuromuscular junction is also 1

prevented.

• No impulse is transmitted to the ske letal muscles 1

• causing paralysis. 1

• A high concentration of curare causes death as the breathing 1

process stops Any 5 Max 5

TOTAL 15 9(a) • HIV enters the body via bodily fluids or blood. 1

• Inside the body,it binds with T helper cell s with corresponding

receptors. 1

• Lipoprotein membrane of HIV fuses with that of the T cell. 1

8

papercollection

• Viral particle enters via endocytosis. I

• Capsid is removed I

• Content of viral RNA and reverse transcriptase enzyme released

into cytoplasrn of host cell. I

• Reverse transcriptase converts viral RNA into single strand DNA. 1

• Single strand DNA convened into double strand DNA by DNA

polymerase. 1

• Viral DNA enters nucleus and incorporates into DNA of host cell

as provIrus. I

Provirus replicates each time the host DNA replicates. 1 • After about 6 years of dormancy, the provirus is transcribed into

1 •

mRNA.

Host cell synthesizes viral capsid, reverse transcriptase enzyme 1

• and viral RNA.

• New viruses formed in the host cell exit the cell by budding. 1

• Virus kills T helper cells and destroys immune system, causing 1

AIDS. Any 8 Max 8

(b) • T cells formed in the bone marrow circulate in the blood I

circulatory system until it reaches thymus glands.

• In thymus glands,T cells are differentiated to form T helper 1 •

cells(Th) and T cytotoxic cells (Tc).

• Each has unique T cell receptor CTCR) on its surface . 1

• Mature Th cell then circulates in the blood circulatory system I

until it meets an antigen presenting cell (APC ).

• The Th cell binds to APC provided the antigen-MHC complex on 1

APC is complimentary with the TCR on the Th cell.

• Intcrleukin I (cytokine) is secreted from APC. 1

Interieukin 1 then stimulates the Th cell to secrete Interleukin 2. 1 • • Interleukin 2 stimulates division ofTh cell to produce clones of

9

papercollection

effector Th cells and memory cells and division of Tc cell to

produce clones of effector Tc cells and memory cells.

• The effector Tc cells bind with antigen-MHC complex on

infected cells.

• Perforin is released by effector Tc cells which will then perforate

infected cells to stimulate autolysis.

• The infected cells go through autolysis while the effector

cytotoxic T cell attacks other infected cells.

• Memory T cells respond for a second invasion of the same

pathogen by actively dividing to form effector T cells.

10(a) • Sketch of curves

a) Stabilising Selection

,

Selecl,en again I bot" exl:el11e~

~ ~ /

I ,

I /

I

I

, -" ~.:~;~ \

:,,~A \ Popula tion

;";1~~~ aller selecllon

:\ \'. Or iginal

'<\"'" '" ,"~)OP\Jlal lorl

The sketch must

- shows the normal distribution curve and the stabilising

selection curve.ldirection of curve.

- labell/selection pressure

TOTAL

1

1

1

1

1

Any 7

2/0

Max 7

15

2

10

papercollection

b) Directional Selection

I _~_._.""_ Population

I

"

I I

I

The sketch must

alter s,ele lJ tion

- shows the normal distribution curve and the stabi lising selection curve.ldirection of curve.

- label//selection pressure

c) Disruptive Selection

, , , ;

S~,,'on "gr'~s~ ''', 'ne,"

, t , ,

I I ,

, , , \ '

The sketch must - shows the normal distribution curve and the stabil ising

selection curve.ldirection of curve. - labell/selection pressure

Sta bi/ising selection

• the bell-shaped curve

• selection favors the intermediate trait value over the extreme

values.

2/0

2/0

1

1

• response to a stable environment// occurs when the environment 1

doesn't change

2

2

11

papercollection

• the mode stays the same

• the population graph gets narrower and taller as selection against

mutation takes place

• experience a decrease in the amount of additive genetic variation for the trait under selection.

Directional Selection

1

1

1 Any 3

• occurs whenever the environment changes in a particular way!! 1

selective pressure for species to change in response to the

environmental change

• directional selection may favor one of the phenotypes at one of

the extremes of the normal distribution!! selection favors one

extreme trait value over the other extreme!! selection favors the

extreme trait values over the intermediate trait values'!! The

average phenotype is selected against more than one other

phenotype is selected for.

1

• the population's trait distribution shifts toward the other 1

extreme!! the mean of the population graph shifts!! One

phenotype can gradually replace another.!/ results in a change in

the mean value of the trait under selection.

• results in a population with new trait!resistant individuals begin 1

to occur and become the dominant type within the population.!/

the variance increases as the population is divided into two

distinct groups. Any 3

Disruptive Selection

• occurs where an environment change may produce selection 1

pressures that favour two extremes of a characteristic!! selection

pressures act against individuals In the middle of the trait

distribution.

• the environment may favor two or more variant phenotypes at 1

Max3

Max3

12

papercollection

the expense of the mean.

a bimodal/two-peaked curve II the two extremes of the curve 1

• create their own smaller curves.

• results in two distinct populations/morphsllthese two forms may 1 become so distinct that they become new populations

• plays an important role in speciation. 1 Any 3 Max3

TOTAL 15

13

papercollection