Stpm Trial 2009 Bio Q&a (kedah)

SULlT'

papercollection

PERCUBAAN STPM 2009

96411

BIOLOGY (BIOLOGI) PAPER 1 (KERTAS 1) MULTIPLE-CHOICE (ANEKA PILIHAN) One hour and forty·'ive minutes (Satu jam empat puluh lima min it)

PEPERIKSAAN PERCUBAAN BERSAMA SIJIL TINGGI PERSEKOLAHAN MALAYSIA (STPM) 2009 ANJURAN PERSIDANGAN KEBANGSAAN PENGETUA-PENGETUA SEKOLAH MENENGAH MALAYSIA (PKPSM) KEDAH

Instructions to candidates: DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO. There are fifty questions in this paper. For each question, four suggested anwers are given. Choose one correct answer and indicate i( on the multiple~hoice answer sheet provided. Read the instructions on the multiple-Choice answer sheet very carefully. Answer all questions. Marks will not be deducted tor wrong answers.

Arahan kepada calon: JANGAN BUKA KERTAS SOALAN INI SEHINGGA ANDA DIBENARKAN BERBUAT DEMIKIAN. Ada lima puluh soa/an dafam kertas info Bag; setlap 5oa/an, empat cadangan jawapan diberikan. Pilih satu jawapan yang betul dan tandakan jawapan flu pada he/aian jawapan aneks pilihan yang dibekaJkan. Baca arahan pada hefaian jawapan aneka pifihan itu dengan teliti. Jawab semua soa/an. Markah tidak akan ditolak bagi jawapan yang safah.

This question paper consists of 35 printed pages (Kertas soalan ini terdiri daripada 35 halaman bercetak)

96411 ."

... _. ---,-- ,-, . . . " ,.... -_ ... :_--- ----..:,----- ,._--- :-, ._-_.

[Lihat sebelah

CONFIDENTIAL'

2

papercollection

The diagram below shows the Suucture of steroid hormone.

o This s,!W!d hormone is known as A B C D

2

Progesterone TestosteroneO1olesterol OestrogCTlI

Which of the following statements is true about tdglyceOdcs? A B

C It

3

It has lower calorific value Iban carbohydrnte)' II forms hydrogen bonds with water molecule,.. It is more dense than w3ter. It has a higher hydrogen to oxygen ratio compared to carbohydrates.

Which afthe foll owing statement is true about eukaryotes and prokaJ'yotes7

Prokaryotes A: B C D

4

Chloroplasts present in cynobacleria. Cell wall consists of ch.i~ No plasmids,).Protein is synthesised by 80 ribosomes

E!!J<aryOles Chloroplasts present in plant cell and algae Cell walJ consists of cellulose HavepJasmids

Protein is synthesised by 70 ribosomes

Which organelle is abundantly found in nerve cells, pancreatic cells and cells of me root apex? A B~ C D

Lysosome Mitochondrion Golgibody Microfilamcnt

96411 *This question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL'

CONFIDENTIAL'

96411

4

papercollection

5

Which statement best explains ~hy .c~~~~iftc in their action? A Enzymes have polypeptide chainsl B Enzyme.,> have large fibrous protein ' C Enzymes are not changed orcoosUlned during reactio!l.\ o Enzymes have spccificswfaceconfiguration

6

lbe Lineweaver-Burl:: plot below shows an enzyme-catalysed reaction. v

W it h

:~.~~~vor

,.--

Wit hout inhibitor

.-

[sl

Which of the foDowing is true for values P and S on the graph?

5

P I

A

K. B

K.

C

~~

.,.

I

K.

~~

K.

7

Calvin Cycle

Bundle Sheath

Cells

Mesophyll

cells \,"

oxaloacetate-- -- -----'l· X What do X, Y and Z represent? y

X

A B C D

Malate Phosphoenoi pyruvate Carbon dioxide Phosphoenol pyruvate

~

Phosphoenol pyruvate

Malate Malate Pyruvate

Z Carbon dioxide Carbon dioxide Phosphocnoi pyruvate Hexose phosphate

964/1 rnN~lnc"MTIJl.I

"

CONFIDENTIAL"

Which enzyme catalyses the fixation of carbon dioxide in the chloroplast of~ mesophyU ceUs?

8

,/"-

,A B C D

9

96411 papercollection

6

PEP carboxylase OxaJoacetate RuBPcarboxylase Malate.

Which of the ronowing reactions in glycolysis is catalysed by RJQspboi~okinase? A

B ('

-D

Fructose I,6-
10 Which of the foDowing statements are true about respiration?

1)( '

Glycolysis causes 6C glucose to be broken up into two 3C pyruvate compound Krebs cycle and electron transport system occur in the ceDcl'tosol.· The Krebs cycle involves ~xyl atiOl)1md dehydrogenation During Glycolysis, substrate-level phosphorylation occurn twice.

A B

I only Uandmonly

~

I, m and IV only I, n, III and IV

.i

n

m-

D

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

CONFIDENTIAL"

8

CONFIDENTIAL'

papercollection 11

The graph below shows the oxygen dissociation cutVe of human haemoglobin under different partial pressures of carbon dioxide. 100 r-

~ :~

i '0

, ,--~............... ....

,' .f 00

i II 1 f ., !

.l·· ...

I

.,/'

~

I .....""

:j...... . ..--.- -

~

,

OJ

'"

PriIII Pf85Ue 0/ oxygeMmi Hg

Arrange the above oxygen dissociation curve based on the ~~c:t.ing.ordcr-O(par!:ial pressure

of carbon dioxide.

12

A .

P~Q~R

B C

P~R~Q

D

R~Q~P

Q~P~R

Why is haemoglobin an efficient transporter of oxygen? It can bind with oxygen at very low partial pressures of oxygen B It dissolves in the plasma C It contains nuclei B - (tcontains haem prosthetic group that has ferum atom at its core.

A

13

The following table shows the phases of cardiac cycle. Which of the following correctly matches each phase of cardiac cycle and its event? Phase

A B p

D

Event

p) Diastole..

l) Atria and ventricles relax. II) Blood flows into the right and left atria. UJ) Ventricles contract

q) Systole

IV) Atrioventricular valves close and semilunar vaJvesopen. . II

ill

p

q

q

P

p .p

q

P

q q

q

p p

q

96411 *Thl.,. ", .,,<>ti............ ,., ........ ~

;~ """"''''~ I I'''\r:''' .... '

.. ,

IV q

P

CONFIDENTIAL' 14

10

96411 papercollection

Which of the following statements are not true about Casparian Strip?

r

It covers the whole endodermisceuT

IT ill r:I

It consists of suberin, which is impenneabJe to water". It is a thickening strip of endodennis cell It ensures that water crosses the root through the apoolast pathway only.

A

Jandll only

B C

nand IYonly ill and IV only I and IV only

I)

Which factors affect the opening and closing of stomata? .

15

Hi W

Concentration of oxygen Changes in lhe potassium ion concentration in the guard cell Omnges in the starch-malate equilibrium Cin:adian mythms.

A

land U only

II

-ll- . U, ill and IV only

J6

C

I, ill and IV only

D

I, u, m and IV

Which homlOne triggers closing of the stomata when soil water is insufficienllo keep up with transpiration. A B

Abscisic aciu (, AntidiweLic OOrmotll

C Auxin Jl ' Gibberellin

17

WalerdiffU5CS into the cytoplasm of one cell and moves from cytoplasm to cytC!plasm through the pL'l <:n"KXIes~ta is called

A lJ. C

apoplasl pathway simplast pathway vacuolar pathway

D

cellulose pathway'

96411 "This question paper is CONFIDENTIAL until the examination is over.

CONFID~NTiAL'

12

CONFIDENTIAL'

96411

papercollection

18

Which hypothesis of translocation in phloem assumes that energy required for translocation is obtained from a potential difference across a sieve' plate?

19

Cytoplasmic streaming hypothesi~

A B £.

Cohesion-tension hypothesis.

D

Perista1tic wave hypolhesis

Electro-osmosis hyphOlhesis

The diagram below shows changes in osmotic concentration in the Loop of Henle. 100

300

Descending 11mb

Ascending

11mb

1200

Which of the following causes a ig..wering of tile os.mot:ic concentration in the ascending limb? A

The decending limb is penncable to dissolve saJutcs).. q. . The ascending limb is penneable to urea.

C D

The ascending limb is penneable to water:' Na+ andCl"ions moveOUl of the ascending limb by active transport ,.

Which of the following statements about the e~,\~s .~~Q. acid in manunal's protein metabolism are true?

20

·n ill 1'\i' A B

{;

o

Deamination occurs and amino acid is excreted as arpQJOnia in urine. Deaminalion occurs and amino group is excreted as u~. , Excreted as albumin in urin~ Produces other amino acid needed through trdnsamination

I and 0 onl)l- ' I and III onl~ 1I and IV only 1Il and IV only

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

CONFIDENTIAL'

CONFIDENTIAL· 23

16

96411 papercollection

The diagram below shows the life cycle of Dryopter;s.

Cll Y'

,.-

--l

P

Zygote

SorUli

~

Egg cell

f

What do P,Q and R represent?

p

po

T

Anlheridium

'-B C

..l ). .f' Q \

f

Archegonium

A

S~r1. Dgium :

Anthero7.oid

Gametophyte Gametophytc Sporophyte Sporophyte

"

S~!"_

\' "

R

--

•

Q Meiosis

R Sporophyte

Sporophyte Gametophytc

Meiosis Meiosis Grunetophyte

Meiosis

... In the life cycle of Mucor sp. mei
24

A B

Development of oospheres Fonnalion of male and femaJe gamete

€ - The fommtion of sporangiwn

o 25

Development of the zygote

Which of the following is the cell-medialed response in inununity? A B

e D

T·lymphocytcs hY9ro1y'se infected £CII. ~J.Watjon of ceUs occurs. Pathogen are destroyed by the action of cytotoxic effcctor T cells. Immunoglobulin are produced. ; .

964/1 ·T h; ............... : .... ~~ ........ r

:... ,.... ....... 'r-' ... .-.'... ,A' .. _., ..... __ .. _ . __ • __ •

18

CONFIDENTIAL'

96411

papercollection 26 TIle table below shows some plant honnones and their functions.

Honnone

Functions

) Auxin (b) Abscisic acid · U •f , ill (c) Ethene (d) Gibberellin " J IV (e) CytoIcinin I V (a)

Promotes 'bolting' in some roselle plants. Promotes fruit ripening. Promotes abscission of fruits and leaves. Promotes stem elongation. Promotes cell division and delays leaf senescence

Which of the following is the correct match ? (a)

IA B

~'

(0)

I

IT I

III

IV

I IV

UJ

(C)

(0)

ill

IV

V

IV I

V V I

III U V

(e)

27 The statements below refer to the mechanism ofhonnone action .

.......r- 'The honnone binds with a specific receptor on the cell membrane. n The hOllllOne crosses the ceDmembI'alK\.

-m- The honnone-receptor complcJt binds with a G protein . •....lY. Adenyl cyclase hydrolyses ATP. V Activation of specific genes in the DNA., Which of the statements describe the action of adrenaJ ~? A

U andV

B

I, U and IV

e'

I, III aod IV I, n , maodV

D

964/1 -This quesHon paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL'

20

CONFIDENTIAL"

28

96411 papercollection

The table below shows three types of germ layers and the tissues or organs which are

fonned from iL Which ofthc following combinations are correct?

Layers

I

Ectoderm (8)". ~ Mesodenn (b) , . -II Endodenn (e) "

I'm

A

Organs or Systems Skeletal, muscle, circulatory, reproductive and kidney Lining of digestive tract. liver and pancreas Epidermis, nervous system

(a)(I), (b)(I.I), (e)(III)

If

(a)(lli), (b)(ll), (e)(I) C (a)(Ill) , (b)(J), (e)(I.I) D ". (a)(ln , (b)(I), (e)(lll)

29

Which ofthc foUowing is incorrectly paired?

A

30

Oxytocin - stimulates rhythmic contraction of uterus during larour....

B

Prolactin- stimulates lactation:.

C D

Oestrogen - inhibits uterus contraction! Progesterone - promotes deve lo pment of mammary glands during pregnanc~

The growth of an organ that is no,!-proportionaJ to that of the whole body is called A

n

e D

isomelric growth allometric growth

intcnnittent growth limited growth

964/1 'This question oaoer is CONFIDENTIAl until th'" """'::Imi ... ",t;",,

I ......,,"' ..

.................... .

,...,.."

96411

22

CONFIDENTIAL'

papercollection

31 The graph below shows experimental data gathered from a bean plant.

,.gIrt

Growtt\ l'IIei

........ -. ~

-"'_ TImo

1oL_ _ _

Which of the (ollowing is correct for curves x, y and z? Absolute Jm)wth rate

,

t-AB

C '<: D

K

Relative growth rate ,), y

Height

y

,

z z

y-

z

Z

Y

,x

A cross belween a pure-breed black cat and a pure breed white cat gives rise to black,

32

white and grey cats with ratio 1: I: 2 respectively in the FI generation, the alleles involved in the traits are probably

A 8

homozygou.. lethal alIel~

{, - codominant

D

link.orl ,

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

CONFIDENTIAL'

24

CONFIDENTIAL'

96411 papercollection

The following family tree shows the inheritance of a blood disease.

33

-,

Key:

o •

"""""mol, Ma~ with disease

o

Honnoll._

•

Female with disease

What is the genetic basis of the blood disease? A B ~

C B

Autosoma.ldo~

Sex-linked dominant Autosoma1 recessivck Sex-linked recessive

~~$I=~I

':;;.

,....- ~

Homologu.

c h~m osome

paIr

34

The diagram above shows a homologous chromosome pair. What type of chromosome mutation has occurred?

A B C

D 3S

Deletion Translocation.. Insertion Inversion

A Ji.nl@g~K~P is composed of ge~leS which

..\ - affect the same characteristic. B arc in the same nucleus. C segregate at mitosis. D are situated on same chromosome.

964/1

CONFIDENTIAL"

36

26

964/1 papercollection

Which of the following changes to a segment of a gene contairungATTCCG triple! code has the most serious effect on an individua11

A B

ACfCCG DACAG

(; . AlTACca D Antrrocca , , In a population that is in Hardy· Weinberg equilibrium, 16% of the individuals show the recessive trait.' Whal is the freq uency afthe dominant allele in the population?

37

A

0.84

Il C

0.36 0.6

D

0.4

Which of the following conditions must be met for a population to be in Hardy-Weinberg equilihriwn?

38

I

Population size is large.

o

Migration onJy occurs dl the begirming of the breeding seaso~

HI JV

Natura] selection does not occur. Mutations occur at conSlant ra~",\

A · It C D

39

ll andYI landDl landll Il , ill, and IV

Which of the following statements is UUc for the J.a&..Qwron?

_A n C D

It is a repressible operon. Lactose is the product. The operon is 'switched on' when repressor is presen ~ It controls acalabolic pathway "

964/1 ·This question paper is CONFIDENT1AL until the examination is over.

CONFIDENTIAL"

28

CONFIDENTIAL'

1be diagram below represents a part of DNA which controls the synthesis of j3·gaJactosidase.

40

The table shows the parts of DNA and their functions.

Pan I

FWlClioo

-4- : ra)

binding site for repressor protein P . (b) codes synthesis of repressor protein (f,' 11c) binding site for RNA polymerase Which of the following combinations is correct?

I

R

P

a

~:

(a)

(b) (c)

(c)

(a) (a)

(b) (c)

I it

Ie

ID

(b) (c) (b)

a

x·O '0 _·Y",,_e /(J ""'"*'c Plasmids A and B have the gene resistance to antibiotic X and Y respectively. What would be the processes involved to generate plasmid C?

41

.....A.- Digestion with restriction enzyme
96411

papercollection 96411

CONFIDENTIAL"

96411

30

papercollection

Which of the following are characteristics of c~?

42

-I . n

They are able to accept foreign DNA. 1hey can replicate freely in their host ceUs.

m

They hann their host cellM

J.V'

They are able to express the cloned genes.

A B C

I and ill DandrV r; U, andill I, U, andIV

- f)

43

Which of the following statement is/are true of an artificial classification system?

I

The system is based on phylogenetic relationship

U'

I1le system can be used to construct dichotomous keys .

IV

Organisms are placed into groups according to their different characteristics which are arbitmriJy chosen.

A

I only landU only n, ill and rV only m and IV only

. m . Organisms are placed into groups for specific purposes.

B C

u

44 The following dichotomous key is prepared for five types of animal 1. Animals with back bone .........................................go to number 2 Animals without back bone ..................................... go to number 3

2,

Body with dry scales.~ .......,.

..................................... P .............................. Q

Body without scales.....

3,

A pair of antennae...

........... go to number 4

Tho pairs of antennae ... ............................................................. R 4.

Three pairs of mouth parts ............................................................ 5 A pair of jaws ............................................................................ T

What is the animal P, Q, R, 5 and T? p

Q

R

T

S

Frog

Cockroach

Prawn

Frog 40 ' Snake

Snake

Cockroach

Centipede

Prawn

Frog

Centipede

Prawn

Cockroach

D ' Snake

Frog

Prawn

Cockroach

Ccnti rxxic

A

Snake

B

Centipede

96411 "This question paper is CONFIDENTIAL until the examination is over.

CO NFIDE NTIAL"

papercollection 96411

32

CONFIDENTIAL'

45 The [able below shows four phyla and their examples

Example

Phylum I Fungi D Bryoph)'la_ ill Filieinophyta · N Angiospennophyta

(a) . Helianthus (b) Dryopreris (c) Marchantia (d) Mucor

Which of the following is correctly matched? I (a) (e) (d) (d)

46

J

.Ilf A B e D

48

ill (e) (a) (b) (b)

IV (d) (b) (e) (a)

Which of the foUowing statements is/are true about the disruptive selection?

.JY

47

II (b) (d) (a) (e)

Destroys the minority individuals from both ends of the phenotypic distribution range. Destroys the majority individuals from the middle of the phenotypic distribution range . Incrca<;es the variation in the population. m only I and ll only II and ill only I, llandm

Which is not associated with spe£iation? A

Isolation

Ir C D

In breeding Genetic drift Adaptive radiation

Which of the following is not true of an ecosystem? A )t C D

96411

Phytoplanktons are producers. The last consumer obtains the highest energYH Ecosystem is an open system with input and output of energies..

Helcrolrophs include herbivores. carnivores, omnivores, decomposers and delritivores.

CONFIDENTIAL'

49

964/1

34

papercollection

Which of the following are correct about the term ~cl).e?

. IThe trophic ievelofan organism in ilScommunity. 'if" '"7he functions of an organism in the fonn of energy flow and nutrient cycle. m The method aChow an orgal}ism makes useofits environment in order to live}' IV A group or plants and animals liVing naturally in an enviroruncnl. V An ecological unit buih from the relationships among the organisms in the community and the relationships between the organisms and the environment. A B

C D

50

'1 and [J IVandV I, II, and III · Ill, IV,andV

x

In an experimc nt .·a~m ~~ m quadrat was used to determine the density of the plant Mimosa pudica in the area R and S. The results of the experiment were as be low.

Quadrat Numbcr ofplanlS in R

I· 5

Number of plants in S

3

2· 10 4

3 9 3

4

5

0

7 I

2

6 6 0

7

5 4

8 9

9 0

I

2

10 9 0

What is the density ofthc plant Mimosa put/iea ~Il- .neler in Rand S?

A

B C

D

Area R

Area S

40 60

20

96 120

16

32 40

964/1 'This question paper is CONFI DENTIAL until the examination is over.

CONFIDENTIAL'

SUlIT" Identity card number............................ . (No. Kad Pengenalan)

Centre nurnberllndex number..... (No. PusatlAngka Giliran)

papercollection

PERCUBAAN STPM 2009

96412

BIOLOGY (BIOLOGI) PAPER 2 (KERTAS 2) Two and a half hours (Dua jam setengah)

PEPERIKSAAN PERCUBAAN BERSAMA SIJIL TINGGI PERSEKOLAHAN MALAYSIA (STPM) 2009 ANJURAN PERSIDANGAN KEBANGSAAN PENGETUA·PENGETUA SEKOLAH MENENGAH MALAYSIA (PKPSM) KEDAH Instruction to candidates: Ansv.-erall the questions in Section A in the spaces provided. Answer anyfour questions from Section B. For this section, write your answers on the answersheet provided.Begin each answer

For examiner's use (Untuk kegunaan pemeriksa) 1

on a fresh sheet of paper, A nswers should be illustrated

by large, clearly labelled diagrams wherever suitable. AnswefS may be written in either Malay or English. Arrange your answers in numerical order and tie the answer sheets to this booklet.

2 3 4

Arahan kepada calon: Jawab semua SOBlan da/am Sahagian A da/am ruang yang disediakan. Ja wab mana-mana empat soalan daripada Sahagian B. Untuk bahagian inf, tufis jawapan anda pada helaian jawapan yang dibekalkan. M ulakan SBtiap jawapan pada heJaian kertas y ang baru. Ja wapan hendaklah disertai gambar rajah yang besar dan mempunyai label yang jelas di mana-mana yang sesuai. Ja wapan bo!ehlah ditulis dalam Bahasa Melayuatau Bahasa

Inggeris. Susun ja wapan snda mengikut tertib berangka dan ikal he/aian ja wapan bersama dengan buku soalan in;.

5 6 7

8 9 10

Total (Jumlah)

This question paper consists of 17 printed pages (Kertas soalan ini terdiri daripada 17 halaman bercelak) 96412 [Turn over (Llhat sebelah "This question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL·

CONFIDEN11AL•

2

96412 papercollection

Section A [40 marks] AlJSwer all lhe questions in this section

The diagram below shows the light·independent reaction of photosynthesis.

~NADPH+H'

(a)

Name RandT.

R : ...... .................................................... . T : .......................................................................... .

[2 marks]

(b) State the source of me NADPH + H+used in the light· indcpendent reaction.

..................................................................................................................... [I mark]

96412 "This question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL"

CONFIOENTIAL'

(c)

96412 papercollection

4

Explain the main stages ofthiscyclc.

[4 marks]

(d) State the differences between light-
[3 marksl

96412

-----,- -"". - ,-

. ..

_-

CONFIDENTIAL' 2

6

96412

papercollection

In a population ofrnts. 64% have agouti coaL Agouti coat is controlled by a recessive allele r,

whereas yelJow coal is controlled by a dominant allele R. (a) Wilh the help of relevant equations, calculate the al lelic frequency of agouti and that of yellow.

[5 marks]

(b) Will the allelic frequency change in the next generation? Explain.

13 marks] (c)

If all the homozygous yellow coat rats die at birth, what is the percentage loss from the total yellow al leles?

[2 marks]

96412 ·This question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL'

3

papercollection 96412

8

CONFIDENTIAL'

The diagram below sho ws part of a tapeworm, Taenia sp.

-----A

(a)

What is meant by parasitic nutrition?

(2 marks]

(b) Parasites can bedivided into obligate andJaculwlive parasites. Explain these two

types of parasites. Obligate parasite . .......................................... .

Facultative paras ite ...

[2 marks]

(c) Name the part labelled A and explain its imponance in the life of the tapeworm. A: ............................... .

importance :

(2 marks]

(d)

(1)

Siale the type of nutri tion in Mucor.

(I mark]

96412 :,...,....

r-

r: 'T

T

..

CONFIDENTIAL' (D)

10

96412 papercollection

Compare the nutrition oftapewonn and Mucor.

[3 marks]

96412 "This question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL'

papercollection CONFIDENTIAL'

4

12

96412

Graph A below shows theconcenlnllion ofFSH and LH in plasma during a woman's menstrual cycle. Graph B shows the concentration of two honnones X and Y produced in the ovary during the same menstrual cycle.

(a)

(i)

Where are the homlOnes in Graph A produced ?

[ I mark] (a)

(Ii)

Ba<>ed on Graph A, slate one function of each homlOnc. FSH: .......... .. ....................................... .

LH : ......... .

[2 marks]

CONFIDENTIAL" (b)

papercollection 96412

14

Based on Graph B, name hormones X and Y.

x......................................................... .

y ......................................................................... . [2 marks]

(c) On which day did ovulation occur in this woman's menstrua1 cycle? Explain the evidence for your answer.

[3 marXs]

(d) Describe an example of negative feedback mechanism involving any of these two

honnones.

[2 marks]

96412 *This question paper is CONFIDENTIAL until the examination is over.

CONFIDENTIAL"

papercollection 16

CONFIOENTIAL'

964/2

Section 8 f60 marks} Answer any rour questions/rom this section.

5

6

(a)

State the importance of transpiration in plants.

(b

Explain the forces that fac ilitate transpiration in plants.

(i)

antigen

(ul

epilope

9

[3 marks] [3 marks] [9 marks]

State three parameters that can be used to measure growth . For each ofthc parameters stated, give its advantages anddisadvaJllagcs.

[9 marks]

Explain me imponance and factors affecting seed donnancy.

16 marks]

(a) Explain briefl y theconcept and the importanceoflaxonomy.

[6 marks]

(b)

Diffcrentiateartificial classification with nanuaJ classification.

[4 marks]

(e)

Explain Ihe steps laken in conslrUcting a dichotomous key.

[5 marks]

(a)

Defi ne the lenn getletic drift. Explain how gellelic drijt occurs in a population.

[8 marks]

(a)

(b)

8

[10 marks]

(al Explain briefly aboul

(b) Describe the humoral immune response in humans.

7

[5 marks]

(b) By usi ng a specific example. explain theconcepl of adaptive radialion.

10 (a) Slate the importancc of conservation oftheccosystem. (b)

964/2

(i)

State why conservation of forests is important.

[7 marks]

[5 marks] [4 marks]

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection

papercollection