SECTION A All questions in this section should be attempted. Answers should be given on the separate answer sheet provided. 1. The diagram below shows an enzyme-catalysed reaction taking place in the presence of an inhibitor.
4. The following synthesis.
information
IRNA anticodon
amino acid carried by IRNA
GUG
Histidine (his)
CGU
Alanine (ala)
GC A
Arginine (arg)
AUG
Tyrosine (tyr)
UAC
Methionine (met)
UG U
Threonine (thr)
.WF"-8*s;' Which line in the table below identifies correctly the molecules in the reaction? Inhibitor
Substrate
Product
A
P
R
S
B
O
P
S
C
R
P
T
D
R
o
T
refers to protein
What order of amino acids would be synthesised from the base sequenceof DNA shown? '
Base sequenceoJ DNA
C GTTA C GTG 2. The following diagram shows a branched metabolic pathway.
> product inhibition
')o
A
arg
-
tyr
-
his
B
ala
-
met
-
his
C
ala
-
tyr
-
his
D
arg
-
tyr
-
thr
a
/D
rr
L +
J\
\{ ---.*
5. In which of the following is the cell organelle listed correctly with its function?
I iR \^,
Cell organelle
Which reaction would tend to occur if both Q and S are present in the cell in high concentrations? A
L --->
B
R- - -> S
114
Function
A
Mitochondrion
Anaerobic respiration
B
Ribosome
Releaseof ATP
C
Lysosome
Synthesis of enzymes
D
Nucleolus
Synthesis of RNA
' :i ......,:
c o-- - * " D
L ----
6. Carrier molecules involved in the process of active transport are made of
tO
3. A fragment of DNA was found to have 120 guanine bases and 60 adenine bases. What is the total number of susar molecules in
this fragment? A60
A
protein
B
carbohydrate
C
lipid
D
phospholipid.
890 c
180
D
360
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7. An investigation was carried out into the uptake of sodium ions by animal cells. The graph shows the rates of sodium ion uptake and breakdown of glucose at different concentrations of oxygen.
160
10. The transmission of a gene for deafness shown in the family tree below.
K"y
d d
40e t
d
a I
I r20
?oâ‚Ź
II ;: -V cd P+
I
ts I
-n
5'
206
x{)
+n -Hl
I I
'H-- +0
10
d9
1
2A
a-)
? ?
O
0
123+ Oxygen concentration
(%)
Calculate the number of units of sodium ions that are taken up over a 5 minute period when the concentration of oxygen in solution is 2%. A 80 B
100
c
400
D
500
8. Which
of the following viruses is true?
statements about
A
Viral protein directs the synthesis of new viruses.
B
New viruses are assembled outside the host cell.
B
recessiveand sex-linked
C
dominant and not sex-linked
D
recessiveand not sex-linked.
11. The examination of a karyotype would detect A
phenylketonuria
B
Down's syndrome
C
the sex of the fetus
D
evidence of non-disjunction.
12. A woman with blood group AB has a child to a man with blood group O. What are the possible phenotypes of the child? A
A orB
B
AB only A B orO
D
Viral DNA viruses.
D
A B ,A orB
It results in the halving of the chromosome number.
B
It results in the pairing of homologous chromosomes.
C
It permits gene exchange homologous chromosomes.
D
It results in the independent assortment of chromosomes.
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Unaffected female
dominant and sex-linked
C
A
Affected female
A
Viral protein is injected into the host cell.
9. What is the significance of chiasma formationl
Unaffected male
This co.ndition is controlled by an allele which is
C
directs the synthesis of new
Affected male
13. Cystic fibrosis is an inherited condition caused by a recessive allele. The diagram below is a family tree showing affected individuals.
16. The table below contains information about four semen samples.
Semen sample
I K
o a
unaffected male
A
affected male
B
C
D
unaffected female
1\umber of sperm rn sample (millions/cm3)
+0 30 20 60
affected female
Active sperm (percent)
50 60
75
+0
Abnormal sperm (percent)
30
10
70
65
Which semen sample has the highest number of active sperm per .-J?
17. Which of the following describes correctly Which two individuals in this family tree must be heterozygous for the cystic fibrosis gene?
the exchange of materials between maternal and fetal circulations?
A
3and5
B
4and6
C
1, and,2
A
D
2and6
B
Glucose
C
14. The diagram below shows the influence of the pituitary gland on testosteroneproduction.
D
Antibodies
into fetus by active transport into fetus by active transport into fetus by pinocytosis into fetus by diffusion
into fetus by active transport into fetus by pinocytosis into fetus by active transport into mother by pinocytosis
Pituitary gland 18. The diffusion pathway of carbon dioxide Hormone X produced
within body tissues is
Testes stimulated Testosterone produced
A
plasma -> t'ssue fluid--> cell cytoplasm
B
lymph -)
C
cell cytoplasm -iltissue fluid --> plasma
D
tissue fluid ->
tissue fluid->
cell cytoplasm
lymph --> plasma.
What is hormone X? A
Luteinising hormone
B
Follicle stimulating hormone
C
Oestrogen
D
Progesterone
15. From which srruc.ure in the reproductive system does a corpus develop? A
Endometrium
B
Graafian follicle
C
Fertilised ovum
D
ljnfertilised ovum
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female luteum
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19. The graph below shows changes in arterial blood pressure.
21. Which of the following statements ref-ers correctly to the cardiac cycle?
i50
A
During systole the atria followed by the ventricles.
B
During systole the ventricles contract followed by the atria.
C
During diastole the atria followed by the ventricles.
D
During diastole the ventricles conrract followed by the atria.
125
T d
100 L
/)
a a L
50
E
contract
contract
25
22. Which 'line in the table below correctly
0 0.5
describes the conditions under which the affinity of haemoglobin for oxygen is highest?
1
Time in seconds The shape of the graph is due to A
the action of the heart muscle
B
the action ofthe diaphragm
C
the closing of the valves in the veins
D
muscular contraction of the arteries.
Oxygen tension
Temperature("C)
A
high
+0
B
high
37
C
low
JI
D
low
+0
20. An ECG trace is shown below.
23. Which of the following is triggered by the hypothalamus in response to an increase in the temperature of the body?
What is the person's heart rate? A
100 beats per minute
B
120 beatsper minute
C
150 beatsper minute
D
200 beats per minute
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A
Contraction of the hair erector muscles and vasodilation of the skin arterioles
B
Contraction of the hair erector muscles and vasoconstriction of the skin arterioles
C
Relaxation of the hair erector muscles and vasodilation of the skin arterioles
D
Relaxation of the hair erector muscles and vasoconstriction of the skin arterioles
24. The graph below shows the rate of sweating of an individual conditions.
in
individualenters warm area
different
25. The diagram below shows the main parts of the
environmental
brain as seen in vertical section.
individualenters cold area
c) E 6. = 6
oh
Which 'tine in the table below correctly identifies the functions of two areas of the brain?
FX c, . e. d-
L'ommunxcahon between hemisbheres
10
20
30
Time (mins) How long after entering the warm area did it take for the volume of sweat production to increaseby 100%? A
8 minutes
B
13 minutes
C
20 minutes
D
23 minutes
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Reasoning
A
w
X
B
x
Y
C
w
Y
D
Z
w
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F-
26. The diagram below shows a test on a man who
had a damaged corpus callosum. This meant that he could no longer transfer information between his right and left cerebral h"rri.;;;;;..
27. Which of the following statements abour diverging neural pathways is correct?
barrier to restrict field ofvision
A
They acceleratethe transmission of sensory impulses.
B
They suppress the transmission of sensory impulses.
C
They decrease the degree of fine motor control.
D
They increase the degree of fine motor control.
28. Which:dfthe following describes the change in
an individual's behaviour where the pres"ence of others causes the individual to show less restraint and become more impulsive?
left cerebral hemisphere
right cerebral hemisphere
A
Social facilitation
B
Shaping
C
Generalisation
D
Deindividuation
Some of the functions of each hemisphere are described in the table below.
29. Which of the following identifies correctly a Left cerebral hemisphere
processin the nitrogen cycle?
Right cerebral hemisphere
processes information from right eye
processes information from left eye
controls language production
controls spatial task co-ordination
The man was asked to look straight ahead and then the words "sno.w,, and .,ball,, were flashed briefly on the screen as shown. What would the man say that he had just seen? A Ball
B
Snow
C
Snowball
D
Nothing
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A
Nitrifying nitrogen.
B
Nitrifying bacteria convert ammonium compounds to nitrates.
C
Nitrogen-fixing bacteria convert nitrates to atmospheric nitrogen.
D
Denitrifying bacteria convert ammonia to nitrates.
bacteria
trap
atmospheric
30. The diagrams below contain information about the population of Britain.
AGE 75+ 70-7+
55-59
,\nnual death rate from coronary heart disease p er 100000 people
50-54 400
5-+9 35-39 30-34 25-29 20-2+ 15-19
200
55-64 55-64 Age (years)
r0-1+ 5-9
0-+ 2.521.5 10.50
00.5 1t.522.5
Populationsize(millions) How many British men between55 and 64 yearsof agedie from coronaryheart diseaseannually? A
400
B
6000
c
12000
D
24000
Candidates are reminded that the answer sheet MUST be returned INSIDE the front cover of this answer booklet.
[Turn over for Section B on Page eleoen.
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