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1. FORVI TP 23178
CARIBBEAN
ADVANqED
)Y!(lC
TEST CODE 00237 4
MAY/JIINE 2OO3
CIL
EXAMINATIONS COUN
PROFICIENCY EXAMINATION
BIOLOGY
1.
2.
3.
4.
UNIT2 - PAPEROl
t I noors
In
a$itlpn tg the 1| hours, candidates are allowed a reading time of
15 minutes. candidates may write in their answer booklets during this
l5-minute period.
ONS CAREFULLY
Candidates must attempt ALL questions in this paper.
Answers are to be written in the spaces provided in this answer booklet.
EACH question is worth 10 marks.
The use of silent non-prograrnmable calculators is alrowed.
Copyright Q 2002 Caribbean Examinations Council.
All riehts reserved.
ii*i.
t

2. -2-
1. Examine Table I below and answer questions (a) and (b) that follow.
TABLE 1
Plant A Plant B
Plant A was supplied with:
. Normal carbon dioxide
. Water, labelled with
radioactive oxygen atoms
Plant B was supplied with:
Carbon dioxide, labelled with
radioactive oxygen atoms
Normal water
(a) Plant A was allowed to photosynthesise.
Predict, with reasons, whichphotosynthetic productofplantAwill containradioactivity.
[3marks]
Plant B was allowed to photosynthesise.
Predict, with reasons, which photosynthetic product of ptant B will contain radioactivity.
[3marks]
(b)
r-:.r.| r.lT 'r.r .rrl-rE rTE,-.n rr a ,.rn

3. -3-
(c) The amount of ATp generated by a prant is shown on the graph in Figure I berow.
12
I
E
6
ATP Generated
ATP Generated
(units)
r20 140
Figure I
;:#'HfJT'HI,:H:::"1'ffi:*lJ;'n" amounr or Arp generated bv the
[2marksJ
(ii) state oNE reason why ATp production does not increase indefiniterv.
[2marks]
Total 10 marks
(i)
Light intensity (units)

4. ,
-4-
In both animals and plants the product of glycolysis is pyruvic acid. Reduced NAD (NADHT)
is also produced. If oiygen is available, thi; NADHz passes ilto the mitochondrion for oxidation
to NAD and water. ii anaerobic condition, o."-ut, the NADF! remains in the cytoplasm'
However, more free NAD is required to maintain the process of glycolysis' Biochemical
pathways exist to recover the NAD from the NADFL'
(a) (i) Which molecule accepts the 2H from the NADII, during anaerobic respiration in
animals?
I lmark]
(ii) What is the product of anaerobic respiration in animals?
(iii)
I lmark]
State TWO products produced under similar anaerobic conditions in plants.
Product I
Product 2
[ 2 marks]
In animals, what happens to the product in (a) (ii) above when oxygen is available again?
[ 2 marks]
(c) If yeast is allowed to grow in a mixture of grapes and sugar in a small laboratory flask,
it metabolizes the sugar to gain energy, and the yeast colony increases in number. After
a few days, the numbers of yeast cells decline and die, despite the fact that usable amounts
of carbohydrates still remain. Suggest TWO reasons for this decline.
I
[ 2 marks]
(b)
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5. -5
(d) Equal amounts of carbohydrate solution were placed in two small Iaboratory flasks. To
one flask was added natural enzymes from a living source. To the other flask was added
an inorganic catalyst. State TwO advantages of using natural enzymes to catalyse the
breakdown of the carbohydrate.
[2marks]
Total 10 marks

6. 3.
-6-
Examine the diagram of the coral reef ecosystem in Figure 2 below.
rii*
iesc ._RlS
#$
Figure 2. Diagram of a Coral Reef Ecosystem
(a) State briefly what happens to a stable ecosystem when it is disturbed.
/'
ol
I
lt.
I
lr
/'.
a
t.l
o) (i) Suggest the effects that removing Species
ecosystem.
Ilmark]
A will have on the coral reef
[ 2 marks]
Species B
'.:.1:i:^
lRht
otr
Spebies D

7. 1
(ii) suggesttheeffects thatremoving SpeciesB will haveonthe coral reef ecosystem'
[ 3 marks]
Examine the passage below and answer question (c) that follows'
Trees in the rain forest rely on mycorrhizae for approximately 9Q 7o of their
nitrogen. Mycontrizae ar" iurrgi which fix Nitrogen (Nr) to ammonia (NHn) so
that the tree can absorb and uti-lize it. The mycorrhizae live on and in the tree
roots, forming a mutualistic, symbiotic relationship. The trees supply carbon
compounds to the mYcorrhizae'
Figure3belowisagraphthatshowsthenitrogenavailabletotreesinthe
foiest after infection with mycorrhizae'
raln
Nitrogen
available
(units)
1800
1700
1500
1500
(i)
(c)
Time (Years)
Figure 3
ExplainwhythenitrogenavailabletotherainforestisNoTzerounitsatthetime
of infection.
Ilmark]
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8. 8-
(ii) suggest an explanation for the shape of the graph in Figure 3 on page 7.
(iii)
[ 2 marks]
on the qTph in Figure 3 on page 7, draw a single line to iilustrate the nitrogen
thatwouldbe available to arain foresttree thatis NoTinfectedwith mycorrhizae.
llmarkl
Total 10 marks

9. 4.
-9-
Figure 4 is a photomicrograph that shows red brood ceils inside a brood vesser
Red blood cells
(a)
(b)
Biotogy, r&-qry_nartn 5th Ed.
T. Audesirk and G Audesirk.
Prentice Hall 1999
Deduce the fype of blood vessel shown in Figure 4. Give ONE reason for your answer.
llmarkJ
g:Tf"r;ft:",,x:fff
:i:T,i;,_"*,
of a red brood cerr, derermine rhe rength of rhe
(i)
(c) After exercising vigorously, a person,
causes the face to appear red.
Itmark]
s face may become flushed red. State what
llmarkJ
(ii) If you were cut wh'e exercising, state oNE way by which you courd determine
whether you had cut an artery J. u u"in.
Figure 4
[1mark]

10. -10-
(d) Figure 5 below shows a diagram of a longitudinal section of the heart.
Figure 5
Clearly indicate on Figure 5 above, the positions of the following:
(i) Sinoatrial node
(ii) Atrioventricular node
(iii) Purkyne tissue [ 3 marks]
Inaconditionknownasfibrillation,theheartpace-makerfails. Deducewhatwouldoccur
as a result of this situation.
[ 2 marks]
Artherosclerosis is a thickening of the artery walls as a result of deposition of fat and
cholesterol in the lining. Deduce the effect this would have on blood pressure.
Ilmark]
Total l0 marks
GO ON TO THF, NF,XT PAGF,
(e)
(f)

11. (a)
o)
- 11 -
Figure 6 is a diagram of the gap befween two neurones.
I
',
3
4
Figure 6
Identify the srructures labelled I to 4 in Figure 6.
[ 2 marks]
(i) What is rhe role of calcium ions at location 2?
[ 2 marks]
(ii) What is the role of protein structures found on the surface of location 4?
9oo% o 3
oooo
[ 2 marks]

12. t2
(c)
(d)
The degradation of the neurotransmitter substance, after it has had its effect at location
4 can be prevented by certain chemicals. Suggest the effects of such prevention on:
(i) The postsynaptic neuron
(ii) The ability of the presynaptic neuron to rebuild synaptic vesicles
Give TWO reasons why the
synapse to exert controls.
[ 2 marks]
method of transmission at K increases the abilify of the
[ 2 marks]
Total 10 marks

13. 13
6. (a) Bananas are harvested tbr shipping
off from the fruit over the f Z aayi
while still green and firm. An analysis of gas given
post harvest, is shown in Figure 7.
lS e
q)
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r0;
q)
>a
L
-
w
-
i
q)
N
r20
100
80
60
40
20
0
ltt
Key----CO,
-Ethylene
Figure 7
comment on the volumes of gases produced, their sequence, and interrelation_
ships.
(ii)
[ 3 marks]
process that causes the effect at days 9 tol0?
Ilmark]
GO ON To Tr{F rTE.'T n a
^F
(i)
002374/CAPF./2.oo"
What is the MAIN chemical
25
20
Days after harvest

14. o)
(iii)
ShippersofgreenbananasfromtheCaribbeantoEuroperecognizethatthemarket
requires nrm, yettow fruit. The voyage between th"
"o"ntti"'
takes 8 days' Compounds
such as Ethnol or Ethephon generate ethylene (ethene). Suggest how this.knowledge
could be used, and whe^n it cJuld be applied to produce a market-ready fruit'
(D How knowledge couldbe used
-14-
StateoNEotherchemicalprocessoccurringinthebananasthatisassociatedwith
this peak.
Ilmark]
[ 1. mark ]
(ii) When the use of that knowledge could be applied
[1mark]
[ 2 marks]
(i)
(c) To delay fruit ripening, shippers may reduce oxygen levels to 5 Vo and increase
levels of nitrogen
"ori".porraingly.
What other process, which also produces
CO, must be guarded against, and whY?
-.
G-r^nn4
GO ON TO THE NEXT PAGE

15. (iD
-15-
Genetically altered forms of ethylene biosynthetic inhibitor enzymes have been
transferred into tomato pf"t1,' Sugg"" Oitle *ay in which the development of
the tomato fruits would be affected'
Ilmark]
Total l0 marks
In the genetic disorder, 'severe combined Immunodeficiency" a defective gene prevents the
synthesis of the
"rrry*"
adenine a"u*irrui", *tti"tt is criticai to immune-system function' A
retrovirus containing the functional gene fo'
'tt" "n'yme
can be used to genetically modify cells
of newborn babies'
(a)Nametherypeoftherapymentionedinthepassageaboveandexplainwhateffectitwould
have on the newborn babY'
[ 2 marks]
(b) AmotherhadababythatsufferedfromsevereCombinedlmmunodeficiencyanddied.
Duringhersecondp,"g,'u,,"v-,.hemothera,t."an"'doctortodetermineifthefoetuswas
carrying the disease.
-fi;"
ONE method which the doctor could use to determine if the
foetus was affected'
Ilmarkl
(c)InSevereCombinedlmmunodeficiencydisorder,stemcellswereisolatedfromthe
newborn, generically modified anii":".La uu.k into the baby' Give oNE other method
by which g";;;i;iy modified g"n",
"un
be introduced into the body.
[Lmark]
GO ON TO THE NEXT PAGE

16. (d)
-16-
The governmentof acountry purchased abatch of genetically modified maize seeds' The
maizecontainedcauliflow".MosuicvirusDNAandisresistanttoherbicides'
Theseeds
are disfibuted to farmers who grow them in a.reas where indigeneous maize varieties are
being grown'
(D outline THREE ways in which the government can determine if the genetically
modified maizehas contaminated the indigeneous maize'
[ 4 marks]
If the indigenous muze has been contaminated by the genetically modified
maize, deduce how the genotype could have been affected.
IlmarkI
(iii) How can the original genotype of the indigenous maize be restored?
Ilmark]
Total l0 marks
(ii)
GO ON TO THE NEXT PAGE

17. (a)
8.
-17-
The graphs in Figure 8 (a) and (b) show the relationship berween cigarefte smoking and
deaths from lung cancer for men and women in Britain over an g0 - year period.
L
q)
Q)
(h
o
q)
0)
a
()
q,
q)
4
0
0
q)
q)
bo
I
q)
z
4500
4000
3500
3000
2s00,
2000
1500
1000
500
0
ls 000
l0 000
KeY
-l-'{--
Cigarettes smoked
- .r - -+
- Deaths per year
1917 7927 1931 1941 1951 7961
Year
Figure 8 (a)
MEN

18. l8
WOMEN
q)
o)
0
q)
€)
,L
o
ta
I
o0
I
O
z
30000
25000
20000
L
O
>|
L
1s000 &
F
I
a
c)
a
10000
5000
0
1911 t92t 1931 t94t 1951 r96t t97l
Year
t99l
+ Cigarettes smoked
- .- - + - Deaths per year
1981
Key
Figure 8 (b)
(i) comment on the relationship between smoking and lung cancer for men.
[ 3 marks]
rlTT NN Tc) TI{F NF,XT PA,GE
(

19. 19-
State THREE ways in which smoking trends and deaths are different in women
than from those shown in men.
l.
[ 3 marks]
Name ONE carcinogen found in the tar exftacted from smouldering cigarettes.
Ilmark]
(c) Briefly describe an animal experiment which has been performed, to directly establish
alink between the inhalation of cigarette smoke and the confirmed development of lung
cancer.
[ 2 marks]
State TWO other diseases caused by smoking.
(ii)
2.
3.
(b)
(d)
Ilmark]
Total 10 marks
/-r. nLY

20. 9.
20-
(a) Complete Table 2 by adding information about the effects of alcohol on behaviour.
TABLE 2
Units of alcohol
Men Women
Blood alcohol
conc. mgl100 cm3
Effects on behaviour
rI -z |
-)
2- 20 -50
5-8 3-5 80 -120
[ 4 marks]
(b) Recommendations for safe consumption levels of alcohol
per week'. This has now been changed to ,units
per day,
the new time period.
used to be expressed in 'units
. Suggest ONE advantage of
(c) The legal upper limit for blood alcohol is g0 mg/l00 cm3.
having more than 35 pg in every 100 cm3 of exhaled air.
(i) Since alcohol is raken into the body through the
analyse the breath?
Ilmark]
A breath test can be failed by
digestive sytem why do we
Ilmark]
GO ON TO TI{E NEXT PAGE

21. I
I
I
j'
_21 _
(ii) State why 35 pg and not 80 mg is the critical point in the brearhalyzer resr?
Ilmark]
(d) State oNE other body fluid that could be used to access alcohol content of the bodv?
Ilmark]
(e) Distinguish berween physical and psychological drug dependence.
[ 2 marks]
Total 10 marks
END OF TEST
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overlooked, or any material has been incorrectly acknowledged, CXC wht Ai pUased to correct this at
the e arlie st opportunity.