biology

1. which feature is visible with a light microscope using a natural light source?
a dnamolecule of diameter 2nm
b paramecium cell of diameter 200 um
c phospholipid bilayer of width 8nm
d_ ribosome of diameter 20nm

2 the electron micrograph shows a structure found in the cytoplasm of an animal cell.
ee
which biological molecules are found in this structure?
1 nucleic acids
2 proteins
3. phospholipids
a 1and3 b 1 only c 2and3 d 2only

3. which cell structures contain nucleic acid?
1 cytoplasm
2 lysosomes
3 mitochondria
a 1,2and3 b 1tand2only c 1and3only d_= 3only

4 mitochondria are thought to have evolved from prokaryotic cells that were ingested by an
ancestral cell.
which feature have prokaryotes lost during their evolution into mitochondria?
a cell wall
b circular chromosome
c_ endoplasmic reticulum
d_ ribosomes

5 which polymers are present in all viruses, all prokaryotes and all eukaryotes?
1 polynucleotides
2 polypeptides
3. polysaccharides
a 1,2and3 b 1and2only c 1and3only d = 2and3only

6 howmany 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

7 steps 1, 2, 3 and 4 are used to test for a non-reducing sugar.

1 put 5cm* of solution into a test-tube.
2 add a few drops of acid.
3. neutralise with alkali.
4 add 6cm* of benedict's solution.

when is the solution heated or boiled?

a between steps 1 and 2

b between steps 2 and 3, and after step 4

c between steps 2 and 3 only

d_ after step 4 only

8 which features contribute to the function of a cellulose molecule?
1 long chains of glucose molecules coil into a helix.
2 many hydrogen bonds form between adjacent chains.
3 it is insoluble in water.
a 1,2and3 b 1and3only c 2and3only d 2only

9 what correctly describes triglycerides?
a_ non-polar molecules that are soluble in ethanol
b_ non-polar molecules that are soluble in water
c polar molecules that are soluble in ethanol
d_ polar molecules that are soluble in water

10 bi butter contains three different triglycerides. these triglycerides are made from the fatty
acids:
* oleic acid (o)
¢ palmitic acid (p)
° stearic acid (s).
the three triglycerides found in cocoa butter are pos, sos and pop.
oe structure of the triglyceride pos is shown next to a diagrammatic representation of
h ohhhhhhhhhhhhhhh
ut, ee
fk
ohhhhhhhhhhhhhhhhh *
lue fel
hhhhhah haar |e
ohhhhhhhhhhhhhhhhh 0
wes seceeseeueeuesnesenh
eotrsoereceeesten
which statement is correct?
a_ triglyceride pop contains two unsaturated fatty acids joined by ester bonds to glycerol.
b_ triglyceride pos contains two less carbon atoms than triglyceride pop.
c_ triglyceride sos contains four more carbon atoms than triglyceride pop.
d_ triglyceride sos contains two saturated fatty acids joined by hydrolysis to glycerol.

11. which molecules contain at least four double bonds?
unsaturated
triglyceride
haemoglobin py.

12 the diagram shows the amino acid glutamic acid.
cooh
oe — ce
i"
what is the r group for glutamic acid?
a nh2
bh
c cooh
d ch,—ch,—cooh

13 the diagram shows three interactions that hold protein molecules in shape.
%
a 4 nh,"
inra ‘i qy ss interaction 34
q coo-
i)
-_ interaction 2
which row identifies these interactions?
[—[_eesiont [teraction [erosions
a hydrogen bond disulfide bond hydrophobic interaction
b hydrogen bond covalent bond ionic bond
c | hydrophobic interaction ionic bond hydrogen bond
d ionic bond disulfide bond peptide bond

14 some animals produce antimicrobial proteins which protect them from pathogens. these proteins
could be used to kill human pathogens, however when used as a medicine they are broken down
by protein-digesting enzymes.

replacing one of the amino acids found in the protein with an amino acid that had been
synthesised in the laboratory resulted in a modified protein that was not broken down.
what could explain why this modified protein was not broken down by the protein-digesting
enzymes?

1 the modified protein has a different tertiary structure to the original protein.

2 the modified protein is not complementary in shape to the enzyme’s active site.

3 the modified protein is unable to induce a fit with the protein-digesting enzyme.
a 1,2and3 b 1tand2only c 1and3only d 2and3only

15 a student investigated the effect of substrate concentration on the rate of an enzyme-catalysed
reaction. a graph was plotted to show the relationship between these two variables. the
student was asked to take readings from the graph that could be used to determine the
michaelis-menten constant, k,,, for this enzyme.

j, k, l and m show points read from the graphs which the student could use to determine the
value of km.
j pail si ca
rate of rate of
reaction reaction
0 0
0 g *
concentration concentration
of substrate of substrate
rate of rate of
reaction reaction i
li 1
() ()
0 0 mm .
concentration concentration
of substrate of substrate
which two readings must the student use to determine the value of km?
a jandk b jandm c kandl d landm

16 the end-product of a metabolic pathway can act as a competitive inhibitor. this is called
end-product inhibition and allows a cell to control a metabolic pathway.
the diagram shows a metabolic pathway where the end-product could act as an inhibitor of
enzyme w.
enzyme w
intermediate 1
enzyme x
intermediate 2
inhibition enzyme y
intermediate 3
enzyme z
end-product
what would be the effect if enzyme z was inhibited by the end-product instead of enzyme w?
quantity of quantity of
intermediate 1 end-product
a increase decrease
b increase unchanged
cc decrease decrease
d decrease unchanged

17 which row shows the distribution of cholesterol and the carbohydrate chains of glycolipids and
glycoproteins in a cell surface membrane?
carbohydrate chains carbohydrate chains
cholesterol ioe :
of glycolipids of glycoproteins
a between phospholipid mainly on the mainly on the
heads only outer surface inner surface
b between phospholipid mainly on the mainly on the
heads only inner surface outer surface
c | between phospholipids mainly on the mainly on the
inner surface inner surface
d | between phospholipids mainly on the mainly on the
outer surface outer surface

18 which row correctly describes all the possible relative concentrations of a substance when the
substance is moved by endocytosis or exocytosis?
| | endocytosis exocytosis
a concentrations equal concentrations equal
b concentrations equal, concentrations equal,
greater inside or greater inside or
greater outside greater outside
cc concentrations equal concentrations equal
or greater outside or lower outside
d concentrations equal concentrations equal
or lower outside or greater outside

19 which statement about simple diffusion is correct?
a_ it requires specific molecules in the cell surface membrane.
b_ it is a passive mode of transporting substances.
c_ it always requires a membrane for transport of substances.
d_ it only happens in the cells of prokaryotes and eukaryotes.

20 plant cells with the same water potential in their cytoplasm were each put into one of three
different concentrations of sugar solution, 10%, 5% and 2.5%.
the cells were left for 50 minutes and then observed using a light microscope.
cell x cell y cell z
vacuole
eo ol
which statements are correct?
1 cell y had a lower water potential than the sugar solution it was put into.
2 cell z was put into the 10% sugar solution.
3 cell z had a less negative water potential than the sugar solution it was put into.
a 1,2and3 b tand2only c t1and3only d 2and3only

21 which row describes some properties of stem cells?
able to divide
ect able to ’
by mitosis to , ae able to repair
differentiate into
produce more oni damaged cells
specialised cells
stem cells
a v j v key
b v v x v= is a property
cc v x x x = is not a property
d x x jv

22 the mitotic index is a measure of the proportion of cells that are undergoing mitosis in an area of
tissue. it is calculated using the formula shown.
mitotic index = (number of cells undergoing mitosis + total number of cells) x 100
a scientist calculated the mitotic index of areas of onion root at different distances from the tip of
the root.
the results are shown.
8 ps ee et
mitotic \
index
4 i
0 02 04 o06 o08 10 12 14 #16 #18 2.0
distance from tip of root/mm
which statement is correct?
a nocell division occurs further than 1.4mm from the tip of the root.
b_ the rate of cell division decreases as the distance from the root tip decreases.
c_ most of the cells undergoing cell division are closer to the tip of the root.
d_ forasample of 200 cells 0.2mm from the tip of the root, 6 would be undergoing mitosis.

23 which molecules make up the structure of atp?
1 adenine
2 thymine
3 deoxyribose
4 phosphate
5 ribose
a 1,2and3 b 1,3and4 c 1,4and5 d 2,4and5

24 a short piece of dna, 19 base pairs long, was analysed to find the number of nucleotide bases
in each of the polynucleotide strands. some of the results are shown.
number of nucleotide bases
strand 1 4
strand 2 ia 5
how many cytosines were in strand 1?
a 2 b 3 cc 5 d7

25 which statement about the role of dna polymerase in the process of semi-conservative
replication of dna is correct?
a dna polymerase forms the hydrogen bonds between complementary base pairs.
b dna polymerase moves along the lagging strand in the 3’ to 5’ direction.
c_ dna polymerase joins new bases to the leading strand only.
d dna polymerase moves along leading and lagging strands in the 5’ to 3’ direction.

26 the diagram shows the process of translation occurring at a ribosome.
; ; ribosome
is}
ca aug
what is the base sequence at s?
a cua b cat c gau d gat

27 which row correctly explains how the structures of phloem sieve tube elements and xylem vessel
elements are related to their functions as transport systems?
| | phloem sieve tube elements xylem vessel elements
a | contain mitochondria to make atp cell walls are thickened and
for the active loading of sucrose contain lignin which makes
into the phloem xylem vessels waterproof
b contain no nucleus so that end walls between cells are
dissolved solutes can move easily | perforated so that water can move
through cells easily through xylem vessels
cc end walls between cells are lignin in cell walls gives strength so
perforated so that dissolved solutes | that xylem vessels do not collapse
can move between cells due to transpiration pull
d | noend walls between cells so that contain no cytoplasm so that a
sucrose solution can move up and continuous column of water can
down the phloem move up the xylem vessels

28 which component of plants is used by the apoplast pathway as water is moved from the soil to
the xylem?
a casparian strip
b_ cellulose
c_ endodermis
d suberin

29 which statements correctly describe transport pathways in dicotyledonous plants?
1 inthe symplast pathway, water may move through intercellular spaces.
2 the symplast pathway may be blocked by the tonoplast.
3. in the apoplast pathway, water does not move through plasmodesmata.
4 the apoplast pathway may be blocked by the casparian strip.
a iand2 b 1and4 c 2and3 d 3and4

30 plants, such as the tobacco plant, retain very little of the water they take in and the volume of
water lost during transpiration is very high. this is because these plants can only absorb
carbon dioxide through open stomata.

plants use carbon dioxide to synthesise glucose molecules. it is estimated that 400 molecules of
water are lost for each carbon dioxide molecule gained.

how many water molecules are lost for a plant to synthesise one molecule of glucose?

a 800 b 1200 cc 2000 d 2400

31 which changes occur as sucrose is transferred from leaves into phloem sieve tubes to be
transported to a sink?
water potential volume of liquid
in phloem sieve in phloem
tubes becomes sieve tubes
a less negative decreases
b less negative increases
cc more negative decreases
d more negative increases

32 the graph shown does not have any axis labels.
pd
0
which row shows appropriate labels for the axes that would explain mass flow in phloem?
se
a distance from sink/m hydrostatic pressure /kpa
b hydrostatic pressure/kpa distance from sink/m
cc distance from source/m hydrostatic pressure/kpa
d hydrostatic pressure/kpa distance from source/m

33 what is present in the blood in human veins?
1 chloride ions
2 carbonic anhydrase
3 oxyhaemoglobin
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

34 the photomicrograph shows two blood vessels p and q.
both these blood vessels are part of a network which transports blood around the body.
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pee bees eh jed s pine o~ sse
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baa ces jae sb see es se: na
* an ee ae ag. re i “y ty
te ss ee, hy ro. gy! a
er me os ee ee
ts pea see
ae as se bie eee
se ee es se
age —e “4 ee it ge igh
which row is correct for blood vessel p and blood vessel q?
| | blood vessel p blood vessel q
a carries blood into arterioles carries blood into arterioles
b carries blood into arterioles carries blood from venules
cc carries blood from venules carries blood into arterioles
d carries blood from venules carries blood from venules

35 the diagram shows a blood capillary and the tissue fluid which surrounds it.
tissue fluid
ww x
arteriole ; venule
z y
and blood capillary and
tissue fluid
tissue fluid is formed when fluid and solutes from blood plasma pass through tiny gaps in the
capillary wall. most tissue fluid is then returned to the blood in the capillary.
which pressures will be needed at points w, x, y and z so that this system can function?
pressure at w pressure at x pressure at y pressure at z
/mm hg /mm hg /mm hg /mm hg
a 18 26 36 26
b 26 26 18 36
cc 26 36 26 18
d 36 18 26 26

36 what happens during ventricular systole in a mammalian heart?
a_ aortic pressure increases.
b_ atrioventricular valves open.
c  semilunar valves close.
d_ ventricular pressure decreases.

37 the photomicrograph shows a part of the human gas exchange system with one tissue
labelled p.
a pa ie 5 he ne ol
i fc at 2 ae a ae |
ws ee ge = = qe
r=> 2a 1 rss
beg us se
f mae oe) ee
ma a oo hee \p gti hae
an 2 a at ce] p
=. ws oe ee he
ali -~ ae 4 i ”) e
gy ng a ff. a! ay le
: ie) se4 ; — yw) 4 pea
iat. sus yn sal 7
po, neca ge,
ss ee. 3
eee ee
f . ‘ ete sd t49 8 eee 3
: ae wee wo liken 2s)
saa ae 9 oe ere
which row is correct?
alt et gas function of tissue p
exchange system
a bronchus regulates the amount of air reaching the lungs
b bronchus provides support and prevents collapse
c bronchiole regulates the amount of air reaching the lungs
d bronchiole provides support and prevents collapse

38 how many times must a molecule of oxygen pass through a cell surface membrane as it diffuses
from the airspace inside an alveolus, through a cell in the capillary wall, to bind to a molecule of
haemoglobin?

a 3 b 4 cc 5 d 10

39 a student wrote four statements about cholera.
which statement is not correct?
a itcan be controlled by vaccination.
b_ it is caused by bacteria spread by ingestion.
c_ hiv/aids increases the risk of infection.
d_ it may be transmitted by animal vectors.

40 monoclonal antibodies are produced using the hybridoma method.
what are removed from the spleen of a mouse to produce monoclonal antibodies?
a antigens
b_ clones
c_ lymphocytes
d_ myeloma cells

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