biology

1. a prokaryotic cell which is 1 sm in diameter is magnified 50000 times in an electron micrograph.
what is the diameter of the cell in the electron micrograph?
a 5x10'mm
b 5x 10°mm
c 5x10'mm
d 5x 10?mm

2 ~the diagram shows a plant cell with some labelled structures.
\e q
oa? g
p q
: __e-
©) o
@
which labelled structures are bound by a double membrane?
a pandq b pands c randq d rands

3. which size of ribosome is found in mitochondria and typical prokaryotic cells?
a 50s b 60s cc 70s d 80s

4 which row about typical prokaryotic cells and typical animal cells is correct?
lysosomes present ‘
for the break down atf is produced
by the cell
of old organelles
a v x
b v v
cc x jv
d x x
key
¥ = correct for typical prokaryotic cells and typical animal cells
x = not correct for both cells but correct for either typical prokaryotic cells or typical animal cells

5 which row is correct for the structures present in typical plant cells and typical animal cells?
| easnectre | plntoot [animal cat |
a plasmodesmata present present
b golgi body present not present
cc centriole not present present
d tonoplast not present not present

6 which row is correct for cellulose?
rotation of alternate hydrogen bonds
shape of molecule

monomers by 180° between molecules
a v branched x key
b x branched v j = present
cc x unbranched x x = not present
d jv unbranched jv

7 which statements about peptide bond formation are correct?

1 the bond formation occurs between a carbon of one amino acid and a nitrogen of
the next amino acid after the amino acids detach from trna.

2 the bond formation occurs at the ribosome while the amino acids are still attached
to trna, and is a hydrolysis reaction.

3 the bond formation is important for growth of an organism and when the bond
forms, a water molecule is removed.

a 1and3 b 2and3 c 2only d = 3only

8 the diagram shows naturally occurring d-glucose and a form of glucose that can be synthesised
in the laboratory, known as l-glucose.
io i
c——oo. c—o
h / | \y ho / | \e
iy 4 | i/ ch.oh = \
cc c cc cc
\ /! ini nw
ho oh h h
i i |
h ho oh h
d-glucose l-glucose
the enzyme glucose oxidase catalyses the oxidation of d-glucose. the enzyme cannot catalyse
the oxidation of l-glucose.
which statement about l-glucose explains this?
a_ l-glucose does not fit into the active site of glucose oxidase.
b_ l-glucose has a different structural formula to d-glucose.
c_ l-glucose is a synthetic sugar.
d_ l-glucose is the mirror image of d-glucose.

9 tests for biological molecules were carried out on three solutions. each solution contained only
one type of biological molecule.
the observations were as follows.
1 benedict’s test blue to orange
2 benedict’s test after acid hydrolysis blue to red
3 biuret test blue to purple
which solutions would contain either sucrose or amylase?
a 1,2and3 b 1and3only c 2and3only d 2only

10 which row describes the expected effect on vmax and k, when a competitive reversible inhibitor is
added to an enzyme-catalysed reaction?
| stetenvon | nana
a no change increases
b no change no change
cc decreases increases
d decreases no change

11 the graph shows the effect of substrate concentration on the rates of reaction of three enzymes,
x, y, and z.
2500
- p| ft | ed
rate of 1500 l, enzyme x
reaction
/ product
—— mane
500 >
eo enfant ead esl ces engyine
0
0 200 400 600 800 1000 1200
substrate concentration / umol dm?
what is the correct order of affinity of these enzymes for their substrates, starting with the
enzyme with the highest affinity?
a x~>y>z b x>z->y c y>x>z d z>x>y

12. which row correctly identifies the weak and strong bonds in the tertiary and quaternary structure
of a typical protein?
a
a strong strong weak weak
b strong weak weak weak
cc weak weak strong strong
d weak weak weak strong

13 which row correctly describes haemoglobin?

a four polypeptide iron ions can in each chain, at 50% saturation,
chains, each associate with hydrophobic r-groups two oxygen
containing a oxygen, forming of amino acids point molecules are
haem group oxyhaemoglobin towards the centre of | transported by the

the molecule molecule

b polypeptide chains each chain consists of two each chain can

interact to produce a|_ contains ahaem identical alpha chains transport an

globular chain group of amino and two identical oxygen molecule
acids surrounding beta chains
an iron ion
cc polypeptide chains an iron ion is quaternary structure | each molecule can
interact to produce | present within each | has two alpha chains | transport a total of
an almost spherical haem group and two beta chains | four oxygen atoms
molecule
d polypeptide chains iron ions in the in each chain, each molecule can
produce a loose molecule can bind | hydrophobic r-groups | transport a total of
helical shape, which reversibly with of amino acids eight oxygen atoms
folds to form a oxygen surround the iron ion
spherical molecule

14 which process always takes place without the involvement of energy from atp?
a active transport
b_ endocytosis
c_ exocytosis
d facilitated diffusion

15 the diagram shows the entry of molecule x into a cell.
lecule x
oo mol
o oo
2)
1? &
© \ (eo)
which row shows a property of molecule x and the effect of the concentration of atp in the
cytoplasm on the rate of entry of molecule x?
property of molecule x concentration of atp in the cytoplasm
a non-polar affects rate of entry of molecule x
b non-polar has no effect on rate of entry of molecule x
cc polar affects rate of entry of molecule x
d polar has no effect on rate of entry of molecule x

16 the electron micrograph shows some human blood cells.
ef : ” ‘ee
x 7 4 :
i p. b
‘ ; as
. =
which row correctly shows the net movement of water by osmosis and the water potential of the
cytoplasm of cell x compared with the solution surrounding the cells?
water potential of
net movement of cytoplasm of cell x
water by osmosis compared with
the solution
a into the cell higher
b into the cell lower
cc out of the cell higher
d out of the cell lower

17 a red indicator solution was mixed with agar and the resulting solid was cut into small cylindrical
blocks. the blocks were placed in an acid which turns the indicator yellow and all other variables
were kept constant. the dimensions of the blocks are shown.

block 1 height 3mm diameter 6mm
block 2 height 6mm diameter 12mm
block3 height 8mm diameter 16mm
the formula for calculating the surface area of a cylinder is 2arh + 2nr?. the formula for
calculating the volume of a cylinder is 2r*h.
which row shows the correct surface area (sa) to volume (v) ratio for each block and the time
taken for the block to turn yellow?
block 1 block 2 block 3
sa to v time to turn sa to v time to turn sa to v time to turn
ratio yellow/mins ratio yellow/mins ratio yellow/mins
a 0.75:1.0 4 1.5:1.0 5 2.0:1.0 11
b 0.75:1.0 11 1.6:1.0 5 2.0:1.0 4
cc 1.33:1.0 4 0.67: 1.0 5 0.5:1.0 11
d 1.33:1.0 ald 0.67:1.0 5 0.5:1.0 4

18 which metabolic processes will be very active in a cell that has just completed cytokinesis?
1 atp formation
2 dna replication
3. protein synthesis
a 1,2and3 b 1and3only c 2only d = 3only

19 the diagram shows a typical mitotic cell cycle and the point in the cell cycle that has been
reached by each of four cells, v, w, x and y.
mitosis oo.
cytokinesis
|
vv
which row correctly identifies the cells that match the two descriptions?
dna replication is ’ preparation tof
complete but the cell microtubule formation
has not yet reached is nearly complete but
tenant size chromosomes have
not yet condensed
a vv x
b ww ¥
cc vv y
d www x

20 the graph shows the mean length of the spindle fibres during mitosis.
which region of the graph shows when all the centromeres have detached from the spindle
fibres?
an
ne |
mean length 1
of spindle i ot '
fibres a 1 |
| d
time

21 the mrna codons acu, acc, aca and acg all code for the same amino acid, threonine.
which anticodons could specify an amino acid other than threonine?
1. uca
2 acc
3  ugu
4 ugc
a 1,3 and4 b 1and2 c 2and3 d 3and 4 only

22 which bond formation does dna polymerase catalyse?
a hydrogen bonds between bases
b_ hydrogen bonds between nucleotides
c_ phosphodiester bonds between bases
d_ phosphodiester bonds between nucleotides

23 in eukaryotes, the rna molecules formed during transcription are modified by the removal of
non-coding sequences. this is followed by the joining together of coding sequences to form
mrna.

what are the coding sequences also called?
a codons

b exons

c introns

d primary transcripts

24 which row correctly identifies sinks for sucrose transported by mass flow in plants?
[esr | es [ae
organ leaf bud shoot tip
a v v v key
b v x v jv =sink
cc x v x x = not a sink
d x x v

25 the diagram shows a transverse section through a transport tissue in a plant.
| ( )
> <->
if fo} fe)
\ / oe. ° oo
4, xe) = e ne -
s a coe) 9 f
a092 0 0 o°
0200
o55
which row correctly identifies cell 1 and cell 2?
[eat
a companion cell phloem sieve tube element
b companion cell xylem vessel element
cc phloem sieve tube element phloem sieve tube element
d phloem sieve tube element xylem vessel element

26 which statement correctly describes the movement of solutes in the symplast pathway?

a cell surface membranes regulate the selective absorption of solutes into the symplast
pathway.

b_ plasmodesmata control the movement of solutes from the symplast pathway to the apoplast
pathway.

c the symplast pathway transports dissolved mineral ions from the soil that cannot be
transported by the apoplast pathway.

d the movement of solutes through plasmodesmata in the symplast pathway is prevented in
the endodermis by suberin.

27 which statement helps to explain why water molecules are forced to move through xylem vessel

elements as a consequence of transpiration?

a_ water molecules form hydrogen bonds with cellulose in the walls of xylem vessel elements in
a process known as adhesion.

b water molecules form hydrogen bonds with neighbouring water molecules in a process
known as cohesion.

c water molecules form ionic bonds with dissolved mineral ions, which helps to keep the water
molecules together in a continuous column.

d_ water has a high latent heat of vaporisation and this prevents the evaporation of water in the
xylem vessel elements.

28 the diagram shows the internal structure of the mammalian heart.
which letter identifies the location of the atrioventricular node?
cc
ery
d

29 the diagram shows pressure changes in the left side of the heart during the cardiac cycle.
=>
va \\
y) \
|
| | key
pressure | ’
/kpa ' \ -——-—- left ventricle
: \ —— aorta
\ ,
| sooooeoes left atrium
xx | \
! \
oe” * ae neccceagasit ten
0 0.2 0.4 0.6 0.8
time/s
what happens in the heart at x?
a the atrioventricular valves close.
b_ the atrioventricular valves open.
c_ the semilunar valves close.
d_ the semilunar valves open.

30 which components of blood are present in tissue fluid?
[| phescones | some prot | sodum ons
a j j v key
b v x x v= present
cc x v v x = not present
d x v x

31. in the lungs, movement of dissolved carbon dioxide out of the capillaries occurs in one of two

ways:

e by diffusion through the endothelial cells of the capillaries

e by leakage through pores in the endothelial cells of the capillaries.
what is the minimum number of times that a carbon dioxide molecule that has been transported
to the lungs in a red blood cell must cross a cell surface membrane to reach an air space in an
alveolus?
a 2 b 3 cc 4 d5

32 what maintains the steep concentration gradients needed for successful gas exchange in the
lungs?
1 air flow in the alveoli is in the opposite direction to blood flow in the capillaries.
2 blood arrives in the lungs with a lower oxygen concentration and a_ higher
carbon dioxide concentration than the air in the alveoli.
3. blood is constantly flowing through and out of the lungs, bringing a fresh supply of
red blood cells.
a 1,2and3 b 1and2only c 1and3only d = 2and3only

33 where is cartilage tissue always found in the human gas exchange system?
a inthe trachea only
b _ inthe bronchi only
c_ inthe bronchioles and trachea
d inthe bronchi and trachea

34 scientists compared the density of goblet cells in the lungs and the density of mucus in the lungs
of three groups of people:
e people who do not smoke and do not have lung disease
e people who smoke tobacco but do not have lung disease
e people who smoke tobacco and have lung disease.
the results are shown in the table.
faith goblet cell density mucus density
sreep /cells per mm? /arbitrary units
non-smokers 19 6
smokers who do not have lung disease 54 26
smokers with lung disease 37 15
what is indicated by these data?
1 there is a positive correlation (relationship) between density of goblet cells and
density of mucus.
2 lung disease results in an increase in goblet cell density.
3 there is an association between tobacco smoking and an increase in mucus
density.
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

35 which disease does mycobacterium bovis cause?
a cholera
b- hiv/aids
c malaria
d tuberculosis

36 an antibiotic inhibits the formation of cross-links between the molecules that form cell walls in
bacteria.
which statements explain why bacteria are killed by the antibiotic?
1 the bacterial cell is destroyed by osmotic lysis.
2 cellulose molecules cannot form hydrogen bonds.
3 the cell wall is no longer partially permeable.
a tand2only b 2and3only c_ 1only d 2only

37 scientists investigated the effect of increasing concentrations of an antibiotic on the development
of antibiotic resistance in bacteria.
the scientists grew four groups of bacteria and added a different concentration of antibiotic to
each group. the number of resistant bacteria and the total population of bacteria were measured
at intervals for 24 hours for each group.
the graphs show the results.
antibiotic concentration = 0 mg dm* antibiotic concentration = 90 mg dm?
10 10
in oe 9
8 8
ae oe
population 6 population 6
of bacteria 5 of bacteria 5
% 108 4 it x 10° 4
3 ee: 3
1 1
0 0
0 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 24
time/hours time/hours
antibiotic concentration = 215mg dm* antibiotic concentration = 600 mg dm
10 10
9 9
8 8
fee tl
population 6 population 6
of bacteria 5 of bacteria 5
x 108 4 x 10° 4
3 3
2 2
1 1
0 0
0 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 24
time/hours time /hours
key
— total population
------ resistant population
which statements are correct conclusions that can be made from the results of this investigation?
1 increasing the concentration of antibiotic decreases the population of non-resistant
bacteria at the end of 24 hours.
2 the proportion of antibiotic-resistant bacteria increases with increasing
concentrations of antibiotics.
3 increasing the concentration of antibiotic always increases the number of resistant
bacteria.
a 1,2and3 b 1and2only c 1and3only d = 2and3only

38 what is the correct sequence of events in a primary immune response?
a_ t-lymphocyte activation + b-lymphocyte selection > plasma cell release
b= antigen presentation by macrophages — cytokines released by t-helper cells —>
b-lymphocyte differentiation
c_ antigen presentation by neutrophils > t-memory cell activation — b-lymphocyte selection
d  t-memory cell activation > b-memory cell activation > antibody production

39 which statement about the properties of the antigen-binding sites in different antibody molecules
is correct?
a_ they are located on the light chains only.
b_ they have a hinge region to give flexibility for different antigens.
c_ they have binding sites for receptors on phagocytes.
d_ they have variable amino acid sequences for different antigens.

40 the diagram shows a stage in monoclonal antibody production.
hybridoma cells
what is represented by x?
a t-lymphocytes
b_ b-lymphocytes
c_ antigens
d antibodies

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