Spm Biology 2007 K2

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bggl tiga fungsi organ X ying b-etul,d.alampitak-petak yang d,isediakan ??d" dalam Jadual t. [3 tnark] rnarkahl [3 (b) Erector muscle is a tissue. State reasons why X is classified as an --- organ --o--- and erector muscle is classified as a tissue. Otot regang ialah tisu. Nyatakan sebab nxengapa. X d'iketaskansebagai organ d,an otot regang sebagai tbu.

X:

Erector muscle I Otot regang:

[2 marks] 12 markahf k) Jlre following information shows :o-ol" of the organ systems found in the human body. Maklurnat berikut menuniukkan beberapo orgoi yang terd,apatd.atam badan manusia. fick (rz) the two systems which contain org€rnX, in the boxes provided below. Tandn (/) basi d'uasistemyang mengand.uogiorgonX"d.alampeiak-petakyang d,ised,iakan di bawah.

|

I tl

n

| Blood circulation system/Sjs tem pered,aran d,arah

Respiratory systenr/Sistem respirasi Integumentary systeml Sistemintegum,en Excretory system/Slstemperku,muhan

[2 marksf (d) Human body temperature is maintained at BZ oC. Suhu badan manusia dikekatkan pad.a g7 "C. Explain the roles of the erector muscle, hair follicle and'sweat gland in maintaining the body temperature on a hot day. Tbranghctn peranan otot regang, bulu rorna d,an kelenjar peluh d.alam ' -----: mengekalkan suhu : badan pada hari yang pa,nos.

193

Erector muscle I Otot regang:

Hair follicle I Bulu ron'La:

Sweat gland I Kelenjar peluh:

tBmarksl [3 markahl Diagram 2.1 and Diagram 2.2 show two different types of movement of substances across the plasma membrane. Rajah 2.I d.an Raiah 2.2 rnenunjukkan dua jenis peigerakan yang berbeza bagi bahan m,erentasi membran plasnt a.

lc "

Substance Bahan -----\ uo

-ttg

!

Diagram 2.1 Rajoh 2.1 Substance Bahon -----

?".r""1 "tf": of ATi

I'1""

@'

@o

O DTagrarn 2.2 Rojah 2.2 194

o

o

0a

Outside the cell 'Luar sel

(a) In Diagram 2.1, label the following structures: Pada Rajah 2.1, Iabel struktur-struktur berikut: Phospholipid bilayer, with letter J Dwilapisan fosfolipid.,dengan huruf J Carrier protein, with letter K Protein pernbawa, d,enganhuruf K [2 rnarks] 12 markahl

(b) state two characteristics of the phospholipid bilayer. Nyatakan dua ciri dwilapisan fisfotipid. ' 1. 2" [2 rnarksl [2 rnarkah] (c)

the process of the movement of substances across the pldsma I"9. membrane as shown in Diagram 2.1and Diagram 2.2. Namakan prosespergerakan bahan merentasi membran plasma yang d,itunjukkan pada Rajah 2.I dan Rajah 2.2. Process in Diagra m 2.L I prosespad,a Rajah 2.I

Process in Diagram,2.Z I proses pad,a Rajah 2.2

[2 marksl 12 rnarkahl (d) (t

Glucosemoleculesare transpo"tq airos: the plasma membrane into the cell through the proces"_"!oytt in Diagram 2.L. Explain *fry Molekul-molekul glukosa ilianghut ke iet merentasi membian plasma melalui proses ydng ditunjukkan pad,a Rbjoh 2.L. Terangh:a,n tnengapa.

,r'#:#;l (iil If the substances in Diagr am 2.2 are calcium ions, describe ho* they are transported into the cell. Jiha bohan pada Raiah 2.2 ad'alah ion-ion halsiurn, huraikan bagaimana ion-ion kalsium tersebut diangkut ke d,a,Iamsel.

[4, marksl 14 rnarkahj 195

Diagram 3.1 shows three stages of mitosis, R Q and R, in an animal cell' Rajih 3.L menunjukkan tiga peringkat mitosis, E Q dan R, dnlarn sel haiwan.

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r'

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Diagran 3.1 Raiah 3.L (a) Name the stages R Q and R in the spacesprovided in Diagram 3.1.

Namakan peringkat 4 Q dan R datarn rucrngydng disediakan dalam Raiah 3-L. tB marksl 13 marhahl

(b) Explain what happens at stage Q. Teranghan apa ycnl,gberlaku pada peringk'at Q.

[3 rnarks] [3 markah] (c) State the chromosome behaviour at the followirrg stages:' Nyatakan perlakuan kromosom pad'a peringkat berikut: Sta g eP lP eringkatP

Stag eF'lP eringhatR

[2 marks] 12 ma,rkahJ

196

(d) Explain the importance of mitosis in the process of cloning orchid plants. Terangkan kepentingan rnitosis d.aram pr6r", pengklonan lokok oriia.

[3 rnarhs] [3 markah] (e) Di4gram3.2 shows a cell at stage P. In the next stage, it is found that chromosomeM rs not separated. Rajah 3'2 rnbnunjukkan suatu sel pad,aperinghat P. Pad,aperinghat seterusnya, d.id.apati kromosomM tidak berpisah.

Chromosome M KromosornM

Diagrarn 3.2 Rajah 3.2 the diagrams for the two daughter cells which will be formed in the space provided -Complete Delow. Lenghapkan raiah kedua-d'ua sel anak yang akan terbentuk pad,a ruang yang d.ised.iaitznndi bawah. II

Daughter cell 1 | Sel anak 1

Daughter cell2 | Sel,anah 2

12marksl [2 marlnhl

197

Diagram 4.1 shows a nucleotide from a DNA molecule. Rajah 4.1 menunjukkan satu nukleotida daripada satu molekul DNA.

Pentose sugar GuIa Pentosa

Diagram 4.1 Rajah 4.1 (a) Name the structures P and Q. Narnakan struktur P dan struktur Q. Pi

a:

12 marksl 12 markahl

(b) A DNA molecule consists of two nucleotide chains. Complete Diagram 4.2 to show a DNA molecule. Part of one of the nucleotide chains has been drawn. Satu molekut DNA terdiri daripada dua rantai nukleotida. Lengkapkan Raiah 4.2 untuk rnenuniukkan satu molekul DNA. Sebahagian daripada satu rantai nukleotid,a itu telah dilukishan.

Diagram 4.2 Rojah 4.2 [3 marks] 13 markahl 1.98

(c) In Diagram 4'3, A, B, c, d dan E- represent the -- genes found on a chromosome. After a ' certain treatment, gene A is found missing. Pada Raiah 4'3, A, B, c, d d,an E rnewg'kit7gen-gen yang terd.apat pad.a suatu kromosom. Selepas suatu rawatan tertentu, gen'A didapati hilang. B

c d

E Diagram 4.8 Rajah 4.8

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{"*"

the process that has taken place on the chromosome. -

Narnakanprosesyang terahberraiu pada,n o*ito*

ili.-

IL mark] IL markahl (ii) Name one factor that causesthe process in a(cXi). Narnakan satrafahtor yang menyebabkoopror"i'd.i ak)G). lL markl lL markahl (d) Diagram 4.4 shows the karyotype of an individual. Rajah 4.4 rnenunjuhhan nalioiii seordng ind.iuid,u.

nffiu illl llilffiililrf ffi 6 7 8 9 1 0 ri:.:

f t il00 13

14

It19 rI 20

lI16 ilf rr 77 18

15

llr

2L

Diagram 4.4 Rajah 4.4 199

IT 22

tr

xx

(r) Determine the sex of the individual. Terutukaniantina indiuidu itu.

f7 mark) IL markah] (ii) Name the genetic disease suffered by the individual' State.a reason. Namakan penyakit genetik yang d,ihidap oleh indiuidu itu. Nyatakan sebab. Disease I Penyakit:

Reason I Sebab:

[2 marks] 12 markahl (e) Diagram 4.5 shows the cross breeding between two mice. Rajih 4.5 meinuniukkan kacuk silang antara dua eko,r tikus.

Homozygousblack fur Homozigotberbuluhitam

Homozygous white fur Hornozigot berbulu putih

Offspring Anak

Black fur Berbuluhitam

Blackfur Berbuluhitarn Diagram 4.5 Raioh 4.5

Black fur Berbuluhitam

Black fur Berbulu hitam

Explain why atl of the o{fripring have black fur. Tbrangkan tnengcrpasenl,uaanak tikus itu berbulu hitam.

[2 marks] [2 marhah] 5

Diagram 5'1 showsthe human vertebral column. Diagram b.2 showsthe two types of vertebrae, R and T in the human vertebral column. Raiah 5'1 menunjukkan turus uertebramaruusia.Raiah 8.2 menunjukkand,uajenis uertebra R dan T, dalam turus uertebra manusia.

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q.

l

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Diagram 5.1 Rojah 5.L

Diagrarn 5.2 Rajah 5.2

(a) Name the vertebrae. Narnakan uertebra-uertebra itu.

ft) Draw arrows (-*----) to match R_and T to any one correct vertebra in Diagram b.1. Lukis anak pa-nah (-----) untuk memad,ankanR 6an T n"ora" ioio-ior* ,otu uertebrayang betul pada Raiah 5'L' [2 marksf [2 markahl 201,

to the mechanism of (c) Explain one feature of thoracic vertebrae which is related respiration , , mekan['srne resplrasl' Teiangkan satu ciri uertebra toraks yatug berkaitan dengan

l3 marksl l3 markah) of the body occurs' (d) Explain the role of the vertebrae in Diagram 5.1 when movement pergerakan badan berlaku' Tbrangkan peranan uertebra pada Raiai 5.1 semasa

12 marksl [2 markahl (e) Diagxam 5.3 shows a cross section of a normal bone tissue. individual suffering from Diagram b.4 shows a cross.section of the bone tissue of an osteoporosis. yang normal' Rajah 5.3 menuniukkan satu keratan rentas bagi tisu tulang yang nxenghidap menunjukkan satu heratan rentas bagi tulang seoratugindiuidu ' Rajah 8.4 ost'eoporosis.

Diag3am 5.4 Roiah 6.4

Diagrnm 5.3 Rojoh 5.3

bone in (i) State the condition of the bone in Diagram 5'4 as compared to the Diagram 5.3. 5'3' Nyatatan keadaan tulang dalam Rajah 5.4 berbanding tulang pada Rajah

ll markl IL markah]

202

(ir) An individual suffering from osteoporosis is advised to drink plenty of milk. Explain why. Indiuidu yang menghidap osteoporosi'sd,inasihatkan meminum banyak susu. Terangkan mengapa.

[2 marks] [2 markah] Seetion B Bahagian B [40 marks] [40 rnarkah] _ Answer any two questions from this section. Jawab nlana-nlano dua soaran d.aripad.a bahagian ini. Diagram 6'1 shows tissue P and cell Q. P is found in a multicellular Q is found in a unicellular organism.

organism.

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Raiah 6'l rnenuniukkan tisu P d'an sel Q. P terd,apat d,alam organisma multisel. e terd.apat dalam. organisma unisel.

Tissue P Tlsu P

Cell Q SeI Q

Respiration equation ' Persamaan respirasi

Respiration equation Persatnqan respirasi

G l u c ose +Oxyg e n .--+'. Capbondioxide + Water +'Enerry Gluhosa + Oksigen.-> Karbon dioksida + Air + Tenaga

Glt:CoSe

Diagram 6.1 Rajah 6.7

203

-+

Carbon dioxide + Ethandl + Enerry Glukosa _-> Karbon dioksida + Etanol + Tenaga

(a) Based on Diagram 6.1, explain the cellular respiration process that occurs in P and in [4 marks]

a.

Berd,asarkan Rajah 6.1, terangha,n.prosesrespirasi sel yang berlaku di P dan di q[4 rytarkah] (b) Diagram 6.2 shows two individuals, M and N, in two different situations. M is in a vigorous activity while N is at rest. nijan G.2 rnenunjukkan d,ua indiuidu, M dan N, dalam dua situasi yang berbeza. M seilang melakukan satu aktiviti cergas manakala N berada dalarn keadaan rehat.

Individu N Indiuidu N

Individu M Indiuidu M Diagram 6.2 Rajah 6.2

Based on Diagram6.2, explain the differencein the physiqlogicalprocessthat occurs in 16 marhsl organs R, S and I for individual M and individual N. Berd,asarkan Rajah 6.2, terangkan perbezaatu prosesfisiologi yang berlaku pada organ R, [6 markah] S d,an T basi ind,iuid.u M dan indiuidu N. (c) A pond contains a lot of aquatic plants. Diagram 6.3 is a graph which shows the changes in the percentages of dissolved oxygen and dissolved iarbon dioxide in the pond over a period of 24 hours. Sebuah kolam mengand,ungi banyah turnbuhan akuatik. Rajg'h 6.3 ialah graf yang menunjukkan perubahan peratusan kandungan oksigen terlarut .dan karbon dioksida terlarut d,alam kolam itu bagi tempoh 24 iam.

204

Percentage Peratusan

Oxygen Oksigen Carbon dioxide Karbon dinksida

0000

0600

1200

2300 fime/hour

1800

Diagram 6.8 Rajah 6.3

Masa/jatn

Basedon the.gralh il Diagram.6.3, explain the differencesin the percentagesof dissolved oxygen and dissolved carbon dioxiie ; ;h; during DU'aEE uurruS' y and stage Z. ,t"s" i,-rtage ;;; rv'rq ! [lO

nlarks]

^''

Berdasarkan graf,padtaR3'iahp.-3,tgrangkanperb,ezaan perubahan peratusan kand,ungdn oksigen terlarut dan karbin d'ioksid,atelhrui d.alamkoiam itu (tt' ii pperingkat x" peringkat 'wov"o t't"'t' Y d'an peringkat z. [L0 markah]

Diagram 7'1 show-s of growth, X, y and z, at thetip of a plant shoot. ln:'-"**:: zones L' 2' 3 and 4 show the ctanges that occur *rin the vrrv wvuD ao*ing the stages of the trL'rll gfowth. "uir" peringkat-peringhat pertumbuhan, x, y, d,an z, pad.a hujung pucuk ?:#:"::".menuniukhan t::r"';n^:ro#r|#.enuniukk'an perubahan vans diatami oleh ser-sel semasa perinskat

Zone LlZon L

- - - - '- t- ,,

zoneziZ&.2

-----

Zone 3lZon B

-

--"-

Zone 4lZon 4

__+

Y

Diagram Z.l Rajah 7.L (a)

-

Pased on Diagram 2.1, explain the meaning of growth. Berdasarkan Rajah 7.!, tiranghan maksud.pertumbuhan.

[4 marks) [4 markah]

(b) (r) Auxin is a plant hormone which helps in plant growth. Diagram 7.2 shows the growth of a plant shoot towards light. Auksin ad.alah hormon tumbuhan yang membantu pertumbuhan tumbuhan. Rajah 7.2 menunjulzkan pertumbuhan pucuk tumbuhan ke arah cahaya. Light rays Sinaran cahaya

Diagran 7.2 Rajah 7.2 Explain the role of auxin'iir the growth of the plant shoot as in Diagtam7.2. [4 marhs] Terangkan perancrn auksin dalam pertumbuhan pucuk tumbuhan seperti pada 14 markahl Rajah 7.2. (ii) State two commercial values of auxin in agriculture. Nyatakan daa ni.lai komersil auksin dalam pertanian. (c) (t

State three differences between primary growth and secondary growth.

f2 marksl 12 markahl l3 m'arksl

Nyatahan tiga perbezaan antanrapertumbuhan primer d.an pertumbuhan sekund'er.

[3 markahf (ii) Explain the benefits to the plants that undergo secondary growth as compared to those that do not undergo secondary growth' 17 marksl How does this affect their economic value? Terangkan kebaikan tumbuhan yang mengalami pertumbuhan sekunder berbanding d,engantumbuhan yang tidak rnengalami pertumbuhan sekunder. Bagaimanakah keadann ini menjejaskan nilai ekonomi tuntbuhan tersebut? l7 markah)

The following organisms are found in a paddy field community. Organisma-organisma berikut terdapat. dalam satu komuniti sawah' padi. Grasshopper, Paddy plant, Caterpillar, Frog, Owl, Snake, Rat Belalang, Pokok padi, Beluncas, Katak, Buru.ng hantu, Ulan Tlhus These organisms interact with each other in the community. Organisina-organisma ini saling berinteraksi antara satu san"Lalain dalam komuniti tersebut.

206

(a) (i) Based on the above organisms, construct: Berdasarkan organisnxa-orgonisma d,i atas, bina: - A food web showing the iriteraction of ail organisms Satu jaringan maleanan yang menunjukkanl,ileraksi semua organisma - A pyramid of numbers consisting of four trophic levers satu piramid nombor yang mengand,ungi empat aras trof [4 marks) [4 markah) (ii) Grasshoppers and caterpillars are pests for paddy plants. How can the population of grasshopp"", urrd caterpillars be controlled? Explain the impact of the control methods on the paddy field community. [6 marks] Belalang d'an beluncas nxerupakan perosak bagi pokok pad.i. Bagaimanakah populasi belalang d,an beluncis iapat d.ihaw:al? Terangha^, impak kaedah pengawalan itu ke atas komuniti sawah pad.i. [6 markah] (b) A paddy field area is developed into an industrial area as shown in Diagram g. Kawasan sawahpadi dibangunkan menjad,ikawasanperind,ustrian sepertiyang d.itunjukkan pada Rajah B.

Diagram 8 Rajah I Discuss the good and the bad social, economic and environmental effects of this development. ILO marksl Bincangkan kesan baik dan kesan buruk sosial. ekonomi dan persekitaran akibat pembangunan ini. [L0 markah]

207

I

(a) Diagram 9.1 shows the process of colonisation and successionin a habitat. Rajah 9.I menunjuhkan prosespengkolonian dan penyesaran dalam suatu h'abitat.

Diagrarn 9.1 Raiah 9.1 What is meant by "colonisation and succession in a habitat"? Based on Diagram 9.1, explain how colonisation and successionbring about the formation of the primary forest in a habitat. ILO rnarksl Apakah yang dimaksudkan dengan "pengkolonian dan penyesaran d,alam suatu habitat'? Berdasarkan Rajah 9.L, teranghan bagaimana pengkolonian dan penyesaran membawa hepada pembentukan hutan primer dalam suatu habitat. lL} markahl (b) Diagram 9.2 shows an ecosystem in Malaysia. Rajah 9.2 menunjukkan suatu ekosistem di Malaysia.

Diagram 9.2 Rajah 9.2 Based on Diagra m 9.2, discuss why the ecosystem has to be maintained.

[10 marks]

Berdasarkan Rajah 9.2, bincangkan kenapa ekosistern ini perlu dikekalkan. llD markahl

208 r-,d

Paper 2 SectionA 1- (a) (t

Skin Tbansporting oxygen Regulating body temperature Eliminating urea Converting excess glucose to glycogen

As a protective layer (b) X: Because skin consists of various types of tissues such as connective tissue; muscle tissue; combined . together to perform specific functions. Erector mriscle: Because erector muscle consists of specialised long cells called muscle fibres . (c) I I

lBlood circulatbry system lRespiratorysystem

I Y llntugomentar5rsystem

I Ylp*"""torysystem (d) Erector muscle: Erector muscles in the skin relax causing the hair to }ie flat. Hair follicle: The hair follicle lies flat to increase the heat loss through conduction and radiation.

(e)

Sweat gland: The sweat gland is stimulated to produce sweat onto the surface ofthe skin where it evaporates and gives a cooling effect to the body. 2

Nuclear membrane

urrli

Nucleolus

(a) Substance Bohon ---_ e\ 'u '

Daughter cell 1 a

q

ffinMffifr

lOutside the Luarsel , I

4

J Inside the cell Dalam sel

Daughter cell 2

(a) P: Phosphate Q : Nitrogenous base

o)

(b)

1. The liydrophilic heads of the outer layer ard in contact with the extr4cellular environment. 2. The hydrophilic tails of the phospholipid molecules form a selective barrier of the plasma membrane. (c) Process in Diagram 2.1: Facilitated difrlsion Processin Diagram 2.2: Active transport (d) (il Glucose molecules are lipid-insoluble and are too large to pass through the pores in the ' plasma membrane. Carrier proteins in the membrane are able to carry'these molecules across the membrane via facilitated diffirsion. (ii) Calcium ions transported into' the cell by active transport tlat move molecules against concentration gradient. . - One site of the carrier protein binds the ' calcium ions and another site binds the ATPmolecule. - The ATP molecule is split into adenosine diphosphate (ADP), phosphate (P) and releases energy to the carrier protein. - These energ'y changes the shape of the carrier protein to release.the calcium ions outside the cell-

3

(t (ii) (d) (r) (ii) (c)

Chromosomhl mutation- deletion Environmental agents such ad radiation. Female Disease:Down's syndrome Reason: Has an extra copy of chromosomes number 21. (e) Tbe allele for black fur is dominant. One of the parents has homozygous for black fur, therefore all of the offspring have black fur. (heterozygous) 5

(a) R : Cervical vertebrae T: Lumbar vertebrae (b)

(a) P : Q: R : (b) 1. 2.

Metaphase Prophase Anaphase The chromosomesbecomeshorter and thicker. Each chromosome consiets of two sister chromatids joined together at the centromers. 3. Spindle fibres begin to form between the centrioles. (c) Stage P: The chromosomes are arranged randomly at the cell e{uator called metaphaseplate. Stage R: The two sister chromatids of each chromosomes are pulled apart to the opposite poles. (d) The use of tissue culture technique where plant tissue are cut into small pieces ealled explants. Explants are transferred into a test tube containing a culture medium. Ttre explants divide through mitosis and develop new shoots. The roots will then develop through mitosis producing young plants.

230

(c) The twelve thoracic vertebrae articulate with the twelve pairs of ribs. Movement of the rib cage €rre brought about by intercostal muscles between the ribs.

temperature is low. Hence, the percentage of dissolved oxygen is low, while the percentage ofcarbon dioxide is high.

(d) Between the vertebrae are intervertebral discs which permit various movements of the vertebral column and absorb vertical shock. (e) (t The bone is thinner, more brittle and more porous. (it Milk contain calcium, phosphorus and vitamin D which are needed for the formation ofbones.

7

Section B (a) Aerobic respiration occurs in P because oxygen 6 is present in this respiration and produce carbon dioxide, water and energy.

(a)

(b)

Anaerobic respiration occurs in Q because oxygen is absent in this respiration and produce carbon dioxide, ethanol and energY. (b) IndividualM

IndividualN The breathing rate at rest is normally 18 to 20 breaths per minute, the lungs enlarge and expand and during inhalation return to its original dome shape during exhalation regularly.

R

The muscles require more oxygen and glucose to release energy, thus rate breathing the increases and the lungs enlarge and expand with more oxygen with each breath.

S

The heart beats fastet The heartbeat rate is so that oxygen can be normal, between 60 to 70 brought to the muscles beats per minute. at a frster rate. In onden to beat faeter, the heart muscle also requires more oxygen, hence tlrere is an increase in the amount of blood flow to it.

T

Blood flow to the kidney is reduced becausemore water is lost through sweat. Therefore, less water is brought to the kidneys by the blood for excretion.

(c)

Growth is an ineversible process which involves a permanent increase in the number of cells, size and volume of cells and cells becomespecialised. Zones 1 and 2 show the number of cells is increasing. 7,ote 3 shows the size of volume of cells is increasing. Zone 4 shows the cells become specialised. (t Auxins show positive phototropism in plant shoots. When a plant is exposedto light from one direction, auxins build up on the side in f,heshade. This causes the cells on the shade region elongate or lengthen more and faster than the cells on the brighter side. As a result, the shoot bending towards the light. (ii) Stimulate the growth of adventitious roots from the stem. Parthenocarpy - induce the development of fruit without fertilisation to produce seedlessfruits. (t Primary growth is the growth of herbaceous plants that occuresafter germination. Secondary growth is the growth of woody perennial plants like forest trees that occurs after primary growth is completed. During primary growth, a plant undergoes cell .division, cell elongation and cell differentiation. During secondary growth, a plant undergoes growth in the diameters of the stems, roots and trunks.

Blood flow to the kidney is higher becausemore water is lost through urine. Therefore, mbre water is brought to the kidneys by the blood for excretion. (ii)

The green aquatic plants use carbon dioxide oxygen to undergo photosynthesis, while gasesare released. At stage X, morning, the rate ofphotosynthesis is low because the light intensity and the temperature is low. Hence, the percentage of dissolved oxygen is low, while the percentage of carbon dioxide is high. At one point, the rate of photosynthesis is equal to respiration' At stageX midday, the rate ofphotosynthesis is high because the light intensity and the temperature is high. Hence, the percentage of dissolved oxygen is high, while the percentage ofcarbon dioxide is low. At stage Z, in t};re evening, the rate of photosynthesis is lower than respiration and the intensity because the light

23L

.

Primary growth begins when meristematic cells .at the apical meristems undergo rapid cell division. Secondary growth begir-rs when lateral meristems. of both the stem and the root undergo rapid cell division. The plants that undergo secondary growth have long lifespans compared to those that do not undergo secondary growth.' Secondary growth produces seconda4i xylem called wood. This woody parts that are stiong and hard makes the plants suitable as beams for buildings and various wodden fixtures such as furniture. Secondary' Crowth Produces more secondary phloem and secondary rylem which form the metlullary rays which is . an attractive feature in furniture like dining tables and decorative items. Some plants that undergo secondary gowth such.as merawan has a tough bark, produce useful resin and oils.

(a)

(r)

Bad economic effects: Demand for food and shelter increase, therefore prices of food increase. Bad environmental effects: 1. Sulphur dioxide from this factories combines with rainwater to form acid rain. 2. Oxides of nitrogen released by the factories dissolved in rainwater to form acid rain. Oxides ofnitrogen can causebronchitis. 3. Carbon monoxide released by the factories combines with hemoglobin and affects the transportation of orygen to body cells. This causesfatigue and headaches. 4. Increase of domestic waste as well as sewage discharge from houses cause water pollution.

Caterpillar--_

Paddy plant

\ Grasshopper-->Fiog

---->

r/

Rat -----+

Owl.

sf,^u./

Afood web Snake Frog Grasshopper, caterpillar, rat Paddy plant (a)

Apyramid of numbers (ii)

The population of grasshopper and caterpillars can be controlled by biological control method through prey-predator interaction. Grasshopper and caterpillars are the prey, while frogs are the predator. When there are sufficient paddy plant in nature, predators and preys control each other's population. When the number of predators increases,the numbdr ofpreys will decreasessince they are eaten by the predators. Hence, the population of snake is increases. Followed by the increasing of owl population. On the other hand, the rat population decreases as a result of increasing predation/snake population. A paddy field area is developed into an industrial area which known as urbanisation. The drive for development has led to social activities, economic activities and various environmental problems, Good social effects: 1. The population in this development area increases rapidly because of migration. This is because the factories increase job opportunity. 2. The factories can produce more food supplies to fulfill the need of human population. Bad social effect: Extreme migration causes living space decreases, Good economic effects: 1. More basic facilities such as hospital and school are built for the better live of humau in this area. 2. A lot of transportation system network are built for the better live of human in this area. 3. New housing project are built to support the increment of human population rapidly.

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Colonisation is a process where spores and seeds of certain plants start to germinate and grow in newly formed areas where no life has existed previously. Succession in a gradual process in which one community changes the environment so that it is replaced by another community. Succession in a disused pond begins with the growth of pioneer species such as phytoplankton, algae and submerged plants like Hydrilla. T'lne fibrous roots of these plants penetrate deep into the soil to absorb nutrients and bind sand particles together. When the pioneer species die and decompose,more organic nutrients are released into the pond. The humus and soil which erode from the sides of the pond are deposited on the base of the pond, making the pond shallower. As a result, this condition becomes more suitable for floating plants such as duckweeds. These floating plants float freely on the surface of the water and receive sunlight directly. The floating plants can be reproduce. rapidly by vegetative propagation causing the submerged plants to die due to lack ofsunlight The submerged plants remaining decomposed increase more organic matter on the base of the pond. At the same time, more erosion occurs at the edge which results in more sediments being deposited on the base of the pond. The pond becomes shallower which makes it suitable for emergent plants such as sedges.

When these emergent plants die, their remaining decomposedadd to ths ssdimsnts on the base of the pond which makes the pond shallower. The condition of the pond now beeomesmore favourable . for land plants like small herbaceous weeds such as Euphorbia hirta. As time passes, the land becomes drier. Land plants such as shrubs, bushes and woody plants becomenumerous, A primary forest emerges and eventually turns inta tropical rainforest.

(b) _

Diagram 9.2 showsan ecosystemofrainforest. An ecosystem is a community of living organisms such as plant, monkey, deer, snail, butterfly interacting with one another ancl with the non-living environment such as water and temperature. In this ecosystem, the green plants act as producers which directly produee food for deer and the fruits for monkey as well. This ecosystem provides the plants and the animals with the basic resources of life such as shelter, Iiving space,nesting and breeding sites. For example, a single tree can be a habitat for birds and monkeys. Rainforest provide biodensity. Green plants undergo photosynthesis which water, light and carbon dioxide gases are needed. During respiration process, animal releases carbon dioxide gases which is used for photosynthesisprocessby plants. Plants in tropical rainforest provide raw materials for mediciine such as treatment of cancerandAIDS. At the same time, photosynthesis process produces oxygen gases which is used by animal during respiration process. This ecosystem has to be maintained to ensure the snail has space/habitat to live. Otherwise the snail will loss their habitat causing extinction of snail population. This ecosystem provide habitat for butterfly to ensure the population of butterfly maintained. Timber, rubber and organic oils play important role in the country's economies. Nitrogen cycle, pollination and regulation of atmosphere temperature are provided due to the diversity in plants and animals.

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Answer all questions in this section. Jawab sernua soalan dalam bahagian ini.

Diagram 1 shows a cross section of organ X in the human body. Rajah L merutnjukkan satu keratan rentas bagi organ X dalam badan manusia.

Sweat gland Kelenjar peluh

Diagram 1 Rajah L (a) (r) Name organ X. Namakan organ X.

[l marh] fl markah] (ii) Table 1 shows the function of several organs in the human body. Jadual L menunjukkan fungsi beberapa organ dalam badan rnanusia. Thansporting oxygen Mengangkut oksigen

Regulating body temperature Mengawal suhu badan Eliminating urea Menyinghirkan urea Converting excess glucose to glycogen Menukar glukosa berlebihan kepada glikogen

As a protective layer Sebagai lapisan pelindung Table 1 Jad.uol I 192

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