biology

1 the size of the measles virus, morbillivirus, is approximately 150 nm.
the mimivirus is approximately 4.5 times larger than morbillivirus, whilst the pandoravirus is
approximately 1.5 times larger than the mimivirus.
which viruses can be seen using a light microscope with a maximum resolution of 0.25 1m and
using an electron microscope?
a jv v v key
b x v v /=can be seen
cc x x v x = cannot be seen
d x x x

2 the electron micrograph shows a type of virus at a magnification of x60 000.
ee ci a ono ee ee
cr se = oe
ae te me ee 4
ie . a _ ] 2 oo ae : ns
* oo ee,
— oy
what is the actual length of the virus?
a 1.1nm b 11nm cc 110nm d 1100nm

3. the electron micrograph shows a structure found in the cytoplasm of an animal cell.
oa aaa eo et wee
oe noyce aie a
which biological molecules are found in this structure?
1 nucleic acid
2 protein
3. phospholipid
a i1and3 b 1 only c 2and3 d = 2only

4 four students were asked to match the function with the appearance of some cell structures in an
animal cell.
the functions were listed by number.
1 mrna passes through to the ribosome
2 _ synthesis of lipids
3. packaging of hydrolytic enzymes that will remain in the cell
the appearances were listed by letter.
vs membranes which surround an enclosed inner cavity
w_non-membrane-bound, spherical structures
x adouble membrane interspersed with pores
y non-membrane-bound, cylindrical structures
z membrane-bound sacs, arranged as a flattened stack
which student correctly matched the numbered function with the appearance of the cell
structure?
| | ¢ | 2 | & |
a vv ww z
b vv z y
cc x v ww
d x vv z

5 which are found in typical prokaryotic cells and in typical plant cells?
1 cell wall
2. circular dna
3 cytoplasm
a 1,2and3 b 1and2only c 1and3only d = 2and3only

6 ihe diagram shows some features that occur in organisms.
4 1
rna dna
i) 2
70s protein
ribosomes
which features can be present in viruses?
a 1,2and3 b 1,2and4 c 1,3and4 d 2,3and4

7 diastase is an enzyme that breaks down starch into maltose. maltose is a reducing sugar.
a sample of starch is treated with boiled diastase and left for 15 minutes.
samples of the mixture are then tested with iodine solution and with benedict’s reagent.
what are the results?
[ [eae sation | benes reagent
a blue-black blue
b blue-black red
cc brown blue
d brown red

8 which pair of monosaccharides forms sucrose?
ch,oh ch,oh
h oh h oq. oh
h h
a
oh h oh h
oh oh oh h
h oh h oh
ch,oh ch,oh
h oh h oh
b h h
oh h oh h
oh oh oh oh
h oh h oh
ch,oh et
o
c h h oh
oh h h ch,0h
oh oh oh h
h oh
ch,oh
j hoch, ol oh
h © oh
d h h oh
oh h h ch,oh
a h oh h
h oh

9 the diagram shows the structures of two amino acids.
1 2 4 5
(d-p-good (d-geoap

i ga)o

o
these amino acids will form part of a protein that has a tertiary structure.
which numbered groups could form hydrogen bonds to maintain the tertiary structure of the
protein?
a iand6 b 2and4 c 3and5 d 3and7

10 which row about the structure of proteins is correct?
[pinay siucure | triay srucire | quaternary sree |
a is the number is the result of cross is the polypeptides
of amino acids bonding between that link together
present in a protein all the amino acids in to form a protein
the primary structure
is the order of is the shape formed contains two types
amino acids present by folding of a of polypeptide that
in a protein polypeptide and interact forming the
encoded by dna held together by shape of a protein
hydrogen bonds
cc is the result of is the result of ionic is formed by four
translation of an and hydrogen bonds, polypeptides and
mrna molecule by disulfide bridges an additional
a ribosome into a and hydrophobic reactive group
chain of amino acids interactions between attached to the
amino acids protein
is the sequence is formed as a result is formed by the
of amino acids in of interaction of the linking together
a protein coded by side chains of of more than one
an mrna molecule amino acids in the polypeptide to
primary structure form a protein

11 which row correctly identifies structural features of a collagen molecule and a haemoglobin
molecule?
molecule consists of isbularereiain
more than one polypeptide g p
a collagen and haemoglobin collagen and haemoglobin
b collagen and haemoglobin haemoglobin only
cc haemoglobin only collagen and haemoglobin
d haemoglobin only haemoglobin only

12 which statements describe some enzyme actions?
1 enzymes hold reacting molecules so that their reactive groups are close together.
2 in an enzyme-catalysed reaction, more molecules have sufficient energy to react
than in the absence of the enzyme.
3 reactions catalysed by enzymes take place at a lower temperature than they would
without the enzyme.
a 1,2and3 b 1and2only c 1and3only d = 2and3only

13 lipase is an enzyme that catalyses the hydrolysis of lipids. an experiment was carried out to
investigate changes in ph when lipase is added to a food sample containing a high proportion of
lipids.

the results are shown in the graph.
8 el a i al ne a i a (a a i i i it ei a i i la a a an a a nn i
|
0 |
ga a a a an a ad od dm dn i i il i a an gl a ail a al nan i
i as a a nl
jk a a i el
ka i el
ph of eceeccbreeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeceeeeeeeee eec
food 7 eeeeeeee eee seer eee eee eee eee eee eee eee eee ee eee eee eee
sample | eereeeeeee eee pre eere eee eee
0 |
enes sa ae ee shee eee ee eee eee ee oe ee eee
sss |
0
0
ses 28 se ee ee ee eee ee ee eee
6 es 22 eee ee bees ee ee eee ee eee
0 5 10 15 20 25 30 35 40 45 50 55 60
time/ minutes
which statements are possible explanations of the results of the experiment between 50 minutes
and 60 minutes?
1 enzyme concentration becomes the limiting factor.
2 substrate concentration becomes the limiting factor.
3. all the enzyme active sites are occupied.
4  denaturation of the enzyme by the products takes place.
5 products are acting as competitive inhibitors.
a 1,2and3 b 1,4and5 c 2,3 and4 d 2,4and5

14 the painkiller ibuprofen reduces the activity of an enzyme involved in the production of
prostaglandin.
ibuprofen binds reversibly to the active site of the enzyme.
which type of enzyme inhibition describes this example and why?
a competitive inhibition because ibuprofen alters the shape of the enzyme
b competitive inhibition because ibuprofen and the substrate cannot bind at the same time
c non-competitive inhibition because ibuprofen blocks the active site
d_ non-competitive inhibition because ibuprofen has the same shape as the substrate

15 equal-sized potato pieces were placed into test-tubes containing equal volumes of different
concentrations of sucrose solution and left for 30 minutes. all other variables were controlled.
after 30 minutes, the potato piece in one of the concentrations of sucrose solution had not
changed in size.

what can be concluded from the result for this potato piece?
1 the concentration of sucrose in the potato is the same as the concentration of the
sucrose solution.
2 the water potential of the potato is the same as the water potential of the sucrose
solution.
3. there is no more movement of water into or out of the potato.
a 1,2and3 b jiand2only c t1and3only d 2only
ee  ee_——e

16 four agar blocks are stained green using universal indicator and suspended in 1moldm™~
hydrochloric acid.
beaker
i— acid
po block
the time taken for the agar blocks to change from green to red was recorded.
which agar block would be the first to become completely red?
a 2cmx2cmx2cm
b 2cmxicmx4cm
c 2cmx3cmx2cm
d 5cmx2cmx3cm

17 during the cell cycle, the mass of dna in a cell is doubled.
at which stage in the cell cycle is the mass of dna in a cell reduced?
a anaphase
b_ cytokinesis
c interphase
d_ prophase

18 how many of the listed structures typically contain genetic material that has telomeres?
e bacterial cell
e chloroplast
e — mitochondrion
e nucleus
a 1 b 2 cc 3 d 4

19 in eukaryotes, the chromosomes become shorter and thicker during mitosis. the thickening may
be increased by molecules called protamines. the protamines replace part of the structure of the
chromosome.

which part of the chromosome is replaced by protamines?
a centromeres

b_ chromatids

c histones

d_ telomeres

20 how many hydrogen bonds are holding the two strands of this section of a dna molecule
together?
a 16 b32 c 38 d 48

21 which description of a eukaryotic gene is correct?
a asequence of bases that forms part of a dna molecule and codes for a protein
b  asequence of nucleotides that forms part of a dna molecule and codes for a polypeptide
c asequence of bases that forms part of an rna molecule and codes for a protein
d  asequence of nucleotides that forms part of an rna molecule and codes for a polypeptide

22 the dna sequence ccaagaagtcgacaaaca is translated to synthesise the amino acid chain
gly-ser-ser-ala-val-cys.
as a result of a mutation, the sequence length of the amino acid chain is shortened from six to
two amino acids. a stop codon in mrna is uga.
which base in the dna sequence was changed by the mutation?
a_a bc cc g dt

23 uel combination of features is correct for a phloem sieve tube element as it unloads into a
sink?
oe
a higher than sink absent
b higher than sink present
cc lower than sink absent
d lower than sink present

24 mass flow is the bulk movement of materials from one place to another.
which vessels carry fluids by mass flow?
1 artery
2 phloem sieve tube
3. vein
4 xylem vessel
a 1,2,3and4
b 1,2 and 3 only
c 1 and 3 only
d 2and4only

25 which two rows are correct for the movement of water from the soil into a root?
fot ot
1 lower solute concentration higher solute concentration
2 higher water potential lower water potential
3 | higher solute concentration | lower solute concentration
4 lower water potential higher water potential
a iand2 b 1and4 c 2and3 d 3and4

26 atp is used in companion cells to provide the energy for loading a sieve tube element with
sucrose.
how does the co-transporter mechanism use this energy?
a_ to pump hydrogen ions into the sieve tube element
b_ to pump hydrogen ions out of the companion cell
c to pump sucrose into the sieve tube element
d_ to pump sucrose out of the companion cell

27 why is the mammalian circulatory system described as a double circulation?
a blood flows twice through the heart in one complete cardiac cycle.
b_ blood flows twice through the heart in one complete circuit of the body.
c_ blood remains within arteries, capillaries and veins.
d blood transports both oxygen and carbon dioxide.

28 which sequence of letters correctly identifies the order of events during the cardiac cycle?
t atrial walls contract
u_ impulse is delayed a fraction of a second
v_ wave of excitation enters the atrioventricular node
w_ wave of excitation passes down the purkyne tissue
x wave of excitation spreads from the sinoatrial node
y ventricles contract
a b cc d

29 which factors aifect blood pressure?
1 the diameter of the blood vessels
2 the systolic pressure of the heart ventricles
3. the volume of blood returning to the heart in each cardiac cycle
a 1,2and3 b 1and2only c 1and3only d = 2and3only

30 the diagram is a summary of the role of haemoglobin in the transport of carbon dioxide.
f 1 3
co, in plasma co, + 2—=—4
i:
os 84+ 7
8 gr ci in plasma
o, in plasma 40, 1
1
10 ;
co, in plasma
12

which set of labels is correct?
a 1 = facilitated diffusion, 4 = carbonic acid, 7 = hydrogencarbonate ions
b 2= water, 8 = dissociation, 10 = carbaminohaemoglobin
c 3=carbonic anhydrase, 9 = oxyhaemoglobin, 11 = carbaminohaemoglobin
d 5 =carbonic anhydrase, 6 = hydrogen ions, 12 = red blood cell

31 the graph shows the oxygen dissociation curves of haemoglobin from two species of
mammal, s and t.
is)
percentage
saturation of
haemoglobin
with oxygen t
%
partial pressure
of oxygen/kpa
which statements could explain the difference in the oxygen dissociation curves of species s and
species t?
1 species t has a lower haemoglobin concentration in its red blood cells than
species s.
2 the haemoglobin in species t has a lower affinity for oxygen than the haemoglobin
in species s.
3. species t lives at higher altitudes than species s.
a 1,2and3 b 1and2only c 2only d = 3only

32 which are present in bronchioles?
1 endothelium
2 ciliated cells
3 smooth muscle tissue
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

33 the partial pressure of oxygen in air inside alveoli is 14 kpa.
the partial pressure of oxygen in pulmonary capillaries is 6 kpa.
what will be the effect of these partial pressures on diffusion?
a_ carbon dioxide will not diffuse in any direction.

b oxygen will diffuse from alveoli into capillaries.
c oxygen will diffuse from capillaries into alveoli.
d oxygen will diffuse equally in both directions.

34 which can be directly linked to a reduction in the surface area available for gas exchange in
human lungs?
1 emphysema
2 lung cancer
3. smoking tobacco
a 1,2and3 b tiand2only c t1and3only d 2and3 only

35 which row is correct about the affinity between haemoglobin and the gases carbon dioxide,
carbon monoxide and oxygen?
| piatestatniy west any
a carbon monoxide carbon dioxide oxygen
b carbon monoxide oxygen carbon dioxide
c oxygen carbon dioxide carbon monoxide
d oxygen carbon monoxide carbon dioxide

36 an earthquake caused damage to sanitation systems in a large tropical village.

drinking water became contaminated with sewage. heavy rain then caused flooding and left
large pools of water in the village. housing was destroyed and people in the village had to live in
very overcrowded conditions.
which infectious diseases could increase in the village population as a result of the earthquake
and heavy rain?

1 cholera

2 malaria

3. tuberculosis
a 1,2and3 b 1and3only c = 1only d 2and 3 only

37 which statements about the use of antibiotics could cause an increase in antibiotic-resistant

bacteria?

1 patients do not always complete the course of antibiotics.

2 patients keep unused antibiotics from previous prescriptions and take them at a

later date in smaller doses than prescribed.

3 antibiotics are used in farming to prevent infections.

4 doctors prescribe narrow spectrum antibiotics that only kill a few types of bacteria.
a 1,2and3 b 1,2and4 c 1,3 and4 d 2,3and4

38 which row is correct for neutrophils and b-lymphocytes?
[eon
a can change shape activated by contact with antigens
b found in organs rather than in blood kill virus-infected cells
cc may be long-lived cells always short-lived cells
d | their lysosomal enzymes digest bacteria secrete cytokines

39 rabies is usually a fatal disease. rabies is transmitted to people in the saliva of infected animals.
a person who has been bitten by an infected animal needs immediate treatment.
the treatment is a vaccination against rabies and an injection containing antibodies to the rabies
antigen.
what type of immunity is given by the injection of antibodies?
a artificial active
b artificial passive
c natural active
d natural passive

40 agraft of tissue, such as skin, from a different person is usually rejected by the body.

which statement about graft rejection is correct?

a the graft is rejected by b-lymphocytes because they make and release antibodies which
react with the surface antigens on the graft cells.

b_ the graft is rejected by b-lymphocytes because t-lymphocytes are not stimulated to produce
antibodies.

c_ the graft is rejected by t-lymphocytes because the graft tissue causes t-lymphocytes to
release antibodies.

d_ the graft is rejected by t-lymphocytes because they circulate in the blood and can gather at
the graft site.

Solve 9700_w20_qp_12