biology

1. the diagram below was drawn from an electron micrograph of an animal cell.
“o o ie]
nap
a
°
which diagram would represent the same cell seen under a simple light microscope, using
daylight as the only light source?
a b
a,
on
qd
°
cc d
~ 6 6
eo. “gp
qd
°

2 the diameter of a red blood cell in a diagram was measured as 2.5cm.
the actual diameter of the red blood cell was 7 um.
which calculation would give the correct magnification for the red blood cell in the diagram?
a 7 b 2900 c 28000 p 29000
25000 it 74 7000

3 the diagram shows a fin whale drawn to scale.
za
-h——4
3m

a student made three statements about the diagram.

1 the magnification is x0.006.

2 the ratio of actual size to diagram size is 1667: 1.

3. the fin whale has an actual length of 24m.
which statements are correct?
a 1,2and3 b 1tand2only c t1and3only d = 3only

4 which structures are found in both chloroplasts and mitochondria?
1 70s ribosomes
2 80s ribosomes
3. circular dna
a 1and3 b 2and3 cc 1only d = 3only

5 radioactively labelled amino acids are introduced into a cell that is actively secreting an enzyme.
in which cell structure will the radioactivity first become concentrated?
an
zeaw~
( ‘< \)- 7
fh
aw) e
——= oo
eso
i=
~~ ——*
e 9
o
o.0°
o ie
.
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6 ribosomes exist as separate subunits that are bound together during protein synthesis.
what do these subunits consist of?
a mrna and protein
b mrna and trna
c_ rrna and protein
d rrna and trna

7 four solutions were tested with benedict's solution. the table shows the colour of the solutions
after testing.
1 green
2 blue
3 brick red
4 yellow
which row shows solutions that could have given these results?
[| sotaiont —[souton2—[sotuions—[—soaiona
a 0.05% reducing 0.5% non-reducing 1.0% reducing 0.1% reducing
sugar sugar sugar sugar
b 0.5% reducing 0.0% reducing 1.0% reducing 0.1% reducing
sugar sugar sugar sugar
cc 1.0% reducing 1.0% non-reducing 1.5% reducing 0.5% reducing
sugar sugar sugar sugar
d | 0.05% non-reducing 0.5% reducing 1.0% non-reducing | 0.1% non-reducing
sugar sugar sugar sugar

8 the diagram shows a molecule of three hexose sugars.
‘ica sia ch,oh
w/t ny al °\ oh la \ oh
if | iz y | |
cc cc cc cc cc cc
na ee si (4a is ee oh
i of ee
h oh h oh oh h
1 2 3
which row correctly shows examples of carbohydrates in which these three hexose sugars
occur?
a 1 2 3
b 1 3 2
cc 2 3 1
d 3 2 1

9 which feature of glycogen distinguishes glycogen from starch?
a_ all glycogen molecules are highly branched.
b_ all glycogen molecules are polysaccharides.
c_ allglycogen molecules contain a-glucose.
d_ all glycogen molecules contain 1,4-glycosidic bonds.

10 a student wrote four statements about what happens during hydrolysis of a carbohydrate.
1 disaccharides are formed from monosaccharides.
2 glycosidic bonds are broken.
3 molecules of water are released.
4 monosaccharides can be formed.
which statements are correct?
a 1and2 b 1and3 c 2and4 d 3and4

11 the table compares three molecules, x, y and z, which contain the elements carbon, hydrogen
and oxygen only.
the percentage of carbon, hydrogen and oxygen atoms in each molecule is shown.
x 25.0 50.0 25.0
y 28.5 47.7 23.8
zz 34.6 61.6 3.8
which row correctly identifies molecules x, y and z?
a | monosaccharide disaccharide polysaccharide
b monosaccharide polysaccharide triglyceride
cc polysaccharide triglyceride monosaccharide
d triglyceride monosaccharide polysaccharide

12 which statements about the differences between phospholipids and triglycerides are correct?
1 phospholipids have hydrophobic regions but triglycerides do not.
2 the fatty acids in a phospholipid are always saturated but in a triglyceride they may
be saturated or unsaturated.
3 phospholipids are polar molecules but triglycerides are non-polar.
a 1and2 b 1 only c 2and3 d = 3only

13 an investigation was carried out into the effect of different treatments on the permeability of the
cell surface membranes and tonoplasts of beetroot cells. beetroot cell vacuoles contain a red
pigment. this pigment is unable to pass out of the cells because it cannot diffuse through the
tonoplasts or cell surface membranes.
1cm® cubes were cut from beetroot tissue and washed in running water for 20 minutes to remove
any pigment released from damaged cells.

the cubes were then placed in test-tubes with different contents and observed for five minutes.
which row shows a correct explanation for the observation recorded for one of the treatments?
[terme treeton [ti
a dilute contents of membrane proteins
hydrochloric acid test-tube stay clear have been denatured
ethanol contents of lipids, including membrane
test-tube turn red phospholipids, have dissolved
cc water at 20°c contents of membrane proteins
test-tube stay clear have been denatured
water at 80°c contents of lipids, including membrane
test-tube turn red phospholipids, have dissolved

14 which levels of protein structure can determine the specificity of an enzyme?

1 primary
2 secondary
3 tertiary
4 quaternary

a 1,2,3and4

b 1,2 and 3 only

c 1,2 and 4 only

d 3 and 4 only

15 the graph shows the effect of substrate concentration on the initial rate of an enzyme-catalysed
reaction. the enzyme concentration is constant.
is} l
initial rate of
reaction
r
0
0 substrate concentration

which statement about the graph is correct?
a between r and s the number of enzyme molecules is limiting the rate of reaction.
b_ between r and s the number of product molecules is limiting the rate of reaction.
c_ between s and t the number of enzyme molecules is limiting the rate of reaction.
d_ between s and t the number of substrate molecules is limiting the rate of reaction.

16 the diagram represents the reversible interaction between the active site of an enzyme and
different inhibitors, x and y.
change in the shape
enzyme molecules of the active site of
the enzyme molecule
ba site a ~~ be site
inhibitor x inhibitor y
which row correctly identifies the type of inhibition shown by inhibitor x and inhibitor y?
a ee eee ee
a competitive competitive
b competitive non-competitive
c non-competitive competitive
d non-competitive non-competitive

17. which statements about the movement of water in and out of cells are correct?
1 water moves from regions of more negative water potential to regions of less
negative water potential.
2 water can cross cell membranes by passing through channel proteins.
3 water can pass through cellulose cell walls.
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

18 the diagram shows part of a cell surface membrane.
roeserrak ose
leger
isa\v lar sx s)
onc in 1
srr
cseacs dnd
o—l crocco ati} —2
| ork bp ohne med
| hk ay 40 88 24 \
. \ q fers 3
# v) berry}
hi ne seule
\f \ > )4 prl
apso rab
—8oceg c8
\ 4
5

which row correctly identifies functions of two of the numbered molecules?

[| moteawte | tnoton [moles [———tanaton |
a 1 acts as an antigen 4 stabilises the membrane
b 2 acts as a receptor 5 active transport
cc 3 facilitated diffusion 4 regulates the fluidity of the membrane
d 6 active transport 5 acts as an enzyme

19 during mitosis in animal cells, which process occurs after prophase?
a centrioles move towards the poles of the cell.
b_ centromeres attach to spindle microtubules.
c  chromatids join to form chromosomes.
d chromosomes condense and become visible.

20 embryonic stem cells are able to replicate continuously.
what happens to the telomeres during repeated mitotic cell cycles of embryonic stem cells?
a their lengths increase.
b_ their lengths decrease.
c_ they are completely lost.
d_ they stay the same length.

21 alength of dna was analysed and sequenced. 24% of its nitrogenous bases were adenine.
which percentage of the bases will be cytosine?
a 24 b 26 cc 48 d 76

22 rifampicin is an antibiotic used to treat tuberculosis (tb).
it works by inhibiting rna polymerase in bacteria.
which processes are directly inhibited by this antibiotic?
1 dna replication
2 transcription
3 atp synthesis
a 1,2and3 b 1and2only c 1and3only d 2zonly

23 which terms describe the method by which water is transported within xylem vessel elements?
1 mass flow
2. cohesion-tension
3 osmosis
a 1and2 b 1and3 c 2only d = 3only

24 which combination of features is characteristic of a phloem sieve tube element as it is loaded
from a source?
water patental =o lignification of the cell wall
phloem sieve tube element
a less negative than source absent
b less negative than source present
cc more negative than source absent
d more negative than source present

25 the diagrams show transverse sections of parts of a plant with some transport tissues labelled
from 1 to 6.
leaf stem root
‘ 3
@gesagmo00e8 0.2 2
sse g2
2
which row shows tissues that mainly transport water and tissues that mainly transport sucrose?
mainly transport mainly transport
water sucrose
a 1 and3 4and6
b 1 and6 3 and 5
cc 2 and 3 4and5
d 3 and 5 2 and6

26 which properties of lignin are important for the function of xylem vessels in the stem of a tall
plant, such as a tree?
1 itis inflexible so does not bend easily.
2 it is not permeable to water.
3 it is strong to resist collapse under pressure.
4 it has weaker adhesion to water molecules than cellulose.
a 1,2and3 b 1,2and4 c 1,3 and4 d 2,3 and4

27 a heating sleeve was placed around the trunk of a small tree at a height of 1m above the ground.
this allowed a narrow region of the tree trunk to be heated to 60°c.
how will heating this region to 60°c affect the transport of phloem sap and xylem sap between
the roots and leaves?
movement of movement of
phloem sap xylem sap
a v v key
b v x ¥ = transport continues
cc x v x = transport stops
d x x

28 the photomicrograph shows a section through a structure found in mammals viewed using a light
microscope.
wer ae :
/ vig bi ae aa, sy uae
i ae se. r
>» he . ae
: eee 3 ey ; '
‘, f'\* ia ‘
f eee i
wise |
+ (ose aie ‘a
am bie
aa ce |,
ea: a : pee er
poe a8 ae
eee mg f ww
a wa | ee
<a "ese is bio. f 54 feats,
a ee
ox am —-, ;
4 -
‘ - at ae sees ae
x60
what are the main components of layer w?
a_ collagen fibres only
b elastic fibres and collagen fibres
c smooth muscle and elastic fibres
d squamous epithelial cells forming an endothelium
a ee

29 which row correctly identities the locations in wnicn a type of molecule or cell can be present?
[itt | ae [|
a antigens v x x key
b glucose v x v ¥=can be present
cc lymphocyte x v v x = cannot be present
d neutrophil jv vf j

30 which statements about the formation of haemoglobinic acid are correct?
1 it is linked to the action of carbonic anhydrase.
2 it prevents blood from becoming too acidic by removing excess hydrogen ions.
3. it can only occur when oxygen associates with haemoglobin.
a 1,2and3 b 1tand2only c 1 only d = 2and 3 only

31 the graph shows the oxygen dissociation curves of haemoglobin for eight species of mammal.
100 key
mammals in
decreasing order
percentage 123456 78 of size
oxygen
saturation of 50 if —
h lobi
aemoglobin a gul
4 sheep
5 fox
8 6 cat
0 2 4 6 8 10 12 14 7 i
8 mouse
partial pressure of oxygen/kpa
which conclusion is consistent with the data shown in the graph?
a_ the haemoglobin of larger mammals will combine with oxygen at a lower partial pressure of
oxygen than that of smaller mammals.
b- the haemoglobin of larger mammals will release oxygen at a higher partial pressure of
oxygen than that of smaller mammals.
c_ the metabolic activity of the mammal is directly proportional to the ability of its haemoglobin
to release oxygen.
d_ the size of the mammal is directly proportional to the ability of its haemoglobin to release
oxygen.

32 the statements list some of the events in the cardiac cycle. they are not in the correct order.

1 the impulse travels through purkyne tissue.
2 the ventricles contract.
3 the atrioventricular node delays the impulse for a fraction of a second.
4 the muscle tissue of the sinoatrial node contracts.
5 the wave of excitation sweeps upwards from the base of the ventricles.
6 awave of excitation sweeps across the atria.
7 the atria contract.

which statement describes the second of these events to occur in the cardiac cycle?

a 1 b 4 cc 6 d7

33 which statement about typical bronchioles is correct?
a they have cartilage and ciliated cells.
b_ they have goblet cells and smooth muscle.
c_ they have smooth muscle and cartilage.
d_ they have smooth muscle and ciliated cells.

34 tobacco smoke contains substances that affect the functioning of the human body.

w__ nicotine 1 decreases oxygenation of haemoglobin
x carbon monoxide 2 _ increases risk of cancer
y tar 3. increases risk of blood clotting

what shows the substances matched with their correct effects?

a w-1, x-2, y-3

b~ w-1, x-3, y-2

c w-2, x-1, y-3

d~ w-3, x-1, y-2

35 which two diseases are transmitted by airborne droplets?
a cholera and malaria
b- malaria and measles
c_ measles and tuberculosis (tb)
d_ tuberculosis (tb) and cholera

36 which features do the causative agents of measles, malaria and tuberculosis (tb) have in
common?
aieniasni the ability to surface
ytop produce atp antigens
a v v x key
b v x v v = have in common
cc x v x x = do not have in common
d x x v

37 what explains why most viruses that cause diseases in humans are unaffected by antibiotics?
a viral antigens do not bind to antibiotics.
b_ viral nucleic acids are protected by a protein coat.
c_ viruses contain no ribosomes or mrna.
d_ viruses reproduce inside living eukaryotic cells.

38 why does the white blood cell count increase in people with leukaemia?
a more antibodies are required so there are more b-lymphocytes.
b_ more lymphocytes are produced in bone marrow.
c more memory cells are produced in plasma.
d more t-lymphocytes are required to stimulate the immune system.

39 where are antibodies found during an immune response?
[es [sa
of pathogens | of memory cells
a jv v key
b v x v= antibodies found
cc x v x = antibodies not found
d x x

40 the graph shows the changes that occur in the concentration of antibodies in the blood of a baby
before birth and during the first few months after birth.
birth
i. total antibodies
concentration fj “esa
a — jf antibodies
baby y made by baby
fi antibodies
j from mother
0 2 4 6 8 10 12 14 16
time/months
which description about the changes in immunity during the first few months after birth is correct?
a active artificial immunity decreases, active natural immunity increases
b active natural immunity decreases, active artificial immunity increases
c passive artificial immunity decreases, active natural immunity increases
d passive natural immunity decreases, active natural immunity increases

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