biology

1. the diagram shows a transverse section through a blood capillary.
wall of endothelium
lumen
ih
7um
what is the magnification of the drawing?
a x200 b x245 cc x500 d  x5000

2 which statement explains why lymphocytes with no nucleoli die?
a_ the cells do not have centrioles and cannot divide.
b_ the cells do not have mitochondria and cannot release energy.
c_ the cells do not have mrna and cannot transcribe dna.
d_ the cells do not have ribosomes and cannot synthesise protein.

3 density gradient centrifugation is used to separate cell structures by their relative density. larger
cell structures have greater density and sink further down the centrifuge tube.
what is the correct order of the cell structures, starting from the top of the centrifuge tube?
a_ chloroplasts > nuclei + mitochondria > ribosomes
b nuclei > chloroplasts + mitochondria > ribosomes
c_ ribosomes -> chloroplasts — nuclei > mitochondria
d_ ribosomes — mitochondria > chloroplasts > nuclei

4 which cell structures contain nucleic acids?
1 chloroplasts
2 golgi bodies
3 lysosomes
4 ribosomes
a 1,2and3 b 1,2and4 c 1 and 4 only d 2,3and4

5 the statements describe processes that take place in a secretory cell.

1 modification of the protein occurs in the golgi body.

2 mrna leaves the nucleus.

3 ribosomes bind to mrna during translation.

4 transcription of a specific dna sequence occurs.

5 vesicles fuse with the cell surface membrane.

6 vesicles transport the protein to the golgi body.
statement 4 is the first process, and statement 5 is the last process.
what is the correct sequence of the middle four processes?

a 2>53>51>6
b 2>53>6->1
c 3>2>51>6
d 3>52->6->1

6 how many types of structures with a double membrane that are found in animal cells are also
found in plant cells?
a 1 b 2 cc 3 d 4

7 a naturally occurring polysaccharide synthesised in a plant is a branched chain of a-glucose.
the straight parts of the molecule are linked by a-1,6 glycosidic bonds with only a small number
of branches which are linked by either an a-1,3 glycosidic bond or an a-1,4 glycosidic bond.
which polysaccharide has a structure most similar to that described?
a amylopectin
b_ amylose
c_ cellulose
d_ glycogen

8 the diagram shows a triglyceride.
i
loss oof oos” 8s) oos ™
h,coc
pops oe oe sns ons os ons
hcoc
a a a ae a a a a
h,coc
an enzyme was used to digest this triglyceride into glycerol and fatty acids.
which scatter plot correctly represents each fatty acid component of the triglyceride?
a b
4 x 4
3 3 x
number of number of
carbon-carbon 2 x carbon-carbon 2
double bonds double bonds
1 x 1 x
0 0
15 16 17 18 19 20 15 16 17 18 19 20
number of carbon atoms number of carbon atoms
cc d
4 x 4
3 3 x
number of number of
carbon-carbon 2 x carbon-carbon 2
double bonds double bonds
q x 1 x
0 0
15 16 17 18 19 20 15 16 17 18 19 20
number of carbon atoms number of carbon atoms

9 the diagram shows how the alternating nature of b-glucose monomers along a chain allows
hydrogen bonds to form between consecutive monomers.
ho oh cy
\ f/f hot
f\ af \
0.
“xg — tm sd, bo key
% / . / -++-++- = hydrogen bond
fo jx
ho—c, “ho oh
hydrogen bonds in cellulose affect the tensile strength (the ability to withstand pulling forces
without breaking).
how do the hydrogen bonds shown in the diagram help cellulose function as a suitable material
for a cell wall?
a_ the hydrogen bonds add additional tensile strength along individual cellulose molecules
within the cell wall.
b the hydrogen bonds create stronger crosslinks between adjacent cellulose molecules,
adding to the tensile strength of the cell wall.
c_ stronger hydrogen bonds form between adjacent cellulose molecules, adding to the tensile
strength of the cell wall.
d cellulose molecules within a cellulose microfibril have a stronger link between them,
increasing the tensile strength of the cellulose microfibrils.

10 two solutions, 1 and 2, each contained a mix of two different biological molecules. one solution
contained starch and sucrose, and the other contained glucose and protein.
the two solutions were tested with a variety of reagents to identify the presence of the biological
molecules in the solution.
the table shows the results recorded for the various tests.
which row identifies the two solutions?
ion te boil with
add iodine boil eal benedict's add biuret
‘ benedict’s ‘ :
solution ; solution after solution
solution : :
acid hydrolysis
a v x v x x v x v key
b x v v x v x x v / = positive result
cc v x x v v v x v x = negative result
d x v x jv v v v x

11 the diagrams show parts of three pairs of amino acids within a protein.
the pairs are labelled x, y and z.
xx ¥ z
h h ch, h,c o o
| | f \ 4 \
| & # | 7% fs ‘ f
h h oh h h ch, h,c h nh,* ~o
which row shows the correct type of interaction that would occur between the two amino acids in
each pair?
ee ee ee ee
a hydrophobic interaction hydrophobic interaction hydrogen bond
b hydrogen bond hydrophobic interaction ionic bond
cc hydrogen bond hydrogen bond hydrogen bond
d hydrophobic interaction hydrogen bond ionic bond

12 a student carried out investigations at ph 1-8 to look at the effect of ph on an enzyme-catalysed
reaction.
the optimum condition for this enzyme is the acidic environment of the stomach at ph 1-2.
the remaining substrate concentration was measured after five minutes at each different ph.
which graph shows the effect of increasing ph on substrate concentration remaining after
five minutes?
a b
substrate substrate
concentration concentration
remaining remaining
after five min after five min
123 45 67 8 123 4 5 67 8
ph ph
cc d
substrate substrate
concentration concentration
remaining remaining
after five min after five min
123 45 67 8 123 4 5 67 8
ph ph

13 which statement is correct for a non-competitive inhibitor?
a the inhibitor binds to the active site of the enzyme and decreases vmax.
b_ the inhibitor binds away from the active site and increases the michaelis-menten constant.
c_ the inhibitor decreases vmax, but the michaelis-menten constant does not change.
d_ the inhibitor does not change v,,a, but increases the michaelis-menten constant.

14 pyrophosphatase enzymes catalyse a hydrolysis reaction.
; pyrophosphatase ;
pyrophosphate ions ————————————_ phosphate ions
substrate product
in experiment 1, a scientist studied the rate of this reaction, using a colorimeter.
the absorbance of the solution was measured at regular intervals until all of the pyrophosphate
ions had been converted into phosphate ions.
in experiment 2, the scientist repeated the procedure with a higher concentration of
pyrophosphatase. all other variables were standardised.
which graph shows the effect of increasing the concentration of pyrophosphatase?
a b
absorbance : absorbance
time time
cc d
absorbance / absorbance 7
time time
key
— = experiment 1
+e------ = experiment 2

15 proteases are a group of enzymes that digest proteins.
which statements about proteases are correct?
1. a bacterial protease that is secreted from a disease-causing bacterium could act as
an antibody and cause the production of antigens against it.
2  non-competitive inhibition of a protease that has an optimum condition of ph2 can
be overcome by increasing the substrate concentration and increasing the ph.
3 water molecules are required when peptide bonds that link the monomers together
are broken by the action of proteases in hydrolysis reactions.
a 1,2and3 b 1tand2only c 2only d = 3only

16 the diagram shows part of a cell surface membrane.
o
o
2 os me
jom 1<
cees :
hoot t rae arc) cee
a
> ()
(
j q os
y hss oe
qoqooo_|a_io06 o © 2\€6e
2
which row correctly identifies the molecules labelled 1 and 2?
ee ee
a glycoprotein protein
b glycolipid lipoprotein
cc glycoprotein phosphate head
d glycolipid phosphate head

17 the diagram shows the mean dimensions of an epithelial cell in micrometres (um).
width
* height
°
a al
length 8 um
which row shows the surface area to volume ratio of the epithelial cell and how the surface area
to volume ratio of the cell would change if the cell width doubled?
how surface area: volume
surface area: volume changes if the cell width
doubled
a 12:23 decreases
b 12:23 increases
cc 23712 decreases
d 23:12 increases

18 which diagram shows the correct direction of net water movement between the four cells due to
osmosis?
key
y = water potential
a b
w=-40kpa |} y=-22kpa w=-22kpa || y=-32kpa
w =-36kpa | w=-33kpa w=-16kpa | w=-38kpa
cc d
w=-33kpa || y=-25kpa www=-42kpa || y=-33kpa
w =-33kpa | w=-42kpa w=-24kpa | w=-27kpa

19 an investigation was carried out into the effect of four different treatments on the permeability of
the cell surface membranes and tonoplasts of beetroot cells. beetroot cell vacuoles contain a red
pigment. this pigment 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.

two cubes were then placed in each of the four test-tubes containing different contents and
observed for five minutes.
which row shows a correct explanation for the observation recorded for one of the treatments?
[| weatment [observation [exploration |
a dilute contents of membrane proteins
hydrochloric acid test-tube stay clear have been denatured
b 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
d water at 80°c contents of lipids, including membrane
test-tube turn red phospholipids, have dissolved

20 the photomicrograph shows a stage of mitosis.
what would be correct for the next stage in mitosis?
two sister
. : nuclear
chromatids remain
= on
a no not present
b no re-forming
c yes not present
d yes breaking down

21 what are the correct roles of mitosis?
oie | sep
a v x key
b jv v /¥ = correct
cc x x x = not correct
d x jv

22 which row about the stages of the mitotic cell cycle is correct?
dna ligase used a polymerase
. used in the
in the nucleus
nucleus
a g, phase s phase
b g2 phase mitosis
cc mitosis g, phase
d s phase g, phase

23 which statements describe how a gene mutation can lead to the production of a non-functional
protein?
1 during transcription, an incorrect nucleotide is added to a dna molecule.
2 the mutated gene results in a new codon being transcribed.
3. the order of the bases in an anticodon on trna is altered during translation.
a 1,2and3 b 1tand2only c 2and3o0nly d 2only

24 there are 64 chromosomes in the muscle cells of a particular mammal.
how many dna molecules are present in a cell during early prophase and telophase of mitosis?
| nts [me
a 64 32
b 64 64
cc 128 128
d 128 64

25 the diagram shows the nucleotide sequence of a small section of the transcribed strand of a
gene.
gcg cgc ggc gcg
the table shows the amino acids coded for by 10 mrna codons.
aag lys
acg thr
cgg cgc cgu arg
ccg pro
gcc gcg ala
ggc gly
ugc cys
what is the sequence of the four amino acids in the polypeptide translated from this small
section of a gene?
a ala-ala-cys-ala
b_ala-arg-gly-ala
c_ arg-ala-pro-arg
d arg-arg-thr-arg

26 how many hydrogen bonds form when adenine and cytosine each bind to their complementary
bases?
[adenine | ofosine
a 2 2
b 2 3
cc 3 2
d 3 3

27 which statement correctly identifies the movement of sucrose and amino acids in plant vascular
tissue?
a they are carried from source to sink by mass flow in upward and downward directions.
b_ they are carried from sink to source by cohesion-tension in upward and downward
directions.
c_ they are carried from sink to source by mass flow in one direction.
d_ they are carried from source to sink by cohesion-tension in one direction.

28 xylem vessel elements are specialised cells that are adapted for the transport of water.

which statement correctly matches an adaptation of a xylem vessel element to its function?

a cytoplasm is only found in a thin layer next to the cell walls and does not contain any
organelles. this reduces resistance to the flow of water in the xylem vessels.

b_ the end walls between xylem vessel elements have partially broken down, forming end
plates. this reduces resistance to the flow of water in the xylem vessel.

c_ the walls of the xylem vessel elements contain cellulose that is hydrophilic and can form
hydrogen bonds to water, allowing adhesion of water molecules to the vessel walls.

d xylem vessel elements have plasmodesmata that connect them with companion cells. the
companion cells provide atp, which is needed for the transport of water.

29 a student makes an accurate labelled plan diagram of a section of a leaf containing a vascular

bundle.

which statement correctly describes part of their plan diagram?

a_ the vascular bundle has labels for the xylem vessel elements, phloem sieve tube elements
and companion cells.

b_ the vascular bundle is divided into two sections, with the section closer to the upper
epidermis labelled as xylem and the other section labelled as phloem.

c_ in the section of the vascular bundle positioned closer to the lower epidermis, each sieve
tube element has an associated companion cell.

d_ the phloem sieve tube elements are drawn with thick cell walls to represent the lignin in the
walls.

30 some babies are born with a hole between the right and left atria. these babies are found to
have an increased number of red blood cells.
what is the reason for this increase in red blood cells in these babies?
a_ blood is pumped faster, which causes more blood to circulate in the heart.
b_ more blood is needed in the heart because the pressure is lower.
c_ their haemoglobin has a higher affinity for oxygen.
d_ there is a lower oxygen concentration in the body of the newborn baby.

31 an increase in carbon dioxide in human blood shifts the oxyhaemoglobin dissociation curve to
the right.
what is the explanation for this effect?
a anincrease in carbon dioxide concentration increases the breathing rate.
b_ carbon dioxide is more soluble than oxygen and displaces it.
c diffusion of carbon dioxide between the alveoli and the blood is more rapid.
d increasing the h* concentration decreases haemoglobin affinity for oxygen.

32 ‘heart block’ is a disease which can result in a lower than normal heart rate. a doctor treating a
person with heart block found that electrical impulses were initiated as normal but were not
correctly conducted to the ventricles, so the rate of ventricular contraction was slowed.

which parts may not be functioning correctly in the person with heart block?
1 atrioventricular node (avn)
2 purkyne tissue
3 sinoatrial node (san)

a iand2 b 1and3 c 2and3 d = 3only

33 the pumping action of the heart creates hydrostatic pressure in the blood. the table shows the
hydrostatic pressure in a blood capillary.
arteriole end of venule end of
capillary /kpa capillary/kpa
hydrostatic pressure in blood
about 90% of the tissue fluid which surrounds a capillary is returned to the blood at the venule
end.
how is this achieved?
a_ the capillary wall is more permeable at the arteriole end than the venule end.
b_ the hydrostatic pressure in tissue fluid is higher than in blood.
c_ there is a higher concentration of dissolved solutes in tissue fluid than in blood.
d_ there is osmotic movement of water from the tissue fluid into the blood.

34 what is the function of cilia in the gas exchange system?
a _toincrease the surface area
b_ to move mucus
c_ to produce mucus
d_ to trap dust and pathogens

35 which tissues are present in the walls of a trachea and an alveolus?
epithelium with
smooth muscle
goblet cells
a trachea v v
alveolus x x key
b trachea v jv / = present
alveolus x v x = not present
cc trachea v x
alveolus v v
d trachea x v
alveolus x x

36 the photomicrograph shows part of a bronchus.
which label identifies cartilage?
. at} i. a =
wee fy! ree
jee wi at i <a
d ff x / fas 6 ff
i pe, f uh, ee 4 4
r oig si hee : ms a
de ee sop ng 4 i ay
pee og ae sod, cf ts a chy a3
fe git fo te of : poe tas ate
iy pa ea: } angen eeen 15
ee om 7 a 8 “eee i ao ln
) i: ge wr od ft —
c , mea” 6:4 sp ae ie. o% a v a,
eee a whe ee , ae
bom es. ee ee nail a9 se

37 which structures or compounds are present in a typical cell that can be killed by penicillin?

1 circular dna
2 cytoplasmic dna
3 70s ribosomes
4 peptidoglycan

a 1,2,3and4

b 1, 2 and 4 only

c 1 and 2 only

d 4only

38 three statements about cholera and its transmission are listed.
1 the pathogen causes watery faeces.
2 frequent air flight has led to mobile populations.
3. the pathogen is transmitted through water.
which statements are reasons why outbreaks of cholera are likely to occur?
a 1,2and3 b 1tand2only c j1and3only d = 2and3only

39 what will be produced by the division of memory cells during a secondary immune response?
a macrophages
b plasma cells
c neutrophils
d monocytes

40 a vaccine is used to give immunity to the virus that causes the disease influenza.
a new influenza vaccine is needed every year because the virus mutates regularly.
what is the reason for needing a new influenza vaccine every year?

a memory cells become less effective as they age.

b_ the primary immune response does not produce enough antibodies.

c_ the secondary immune response does not produce enough antibodies.

d_ the virus antigens change and are not recognised by the immune system.

Solve 9700_w24_qp_11