biology

1 agraticule and a micrometer scale can be used to measure the size of biological structures that
are viewed with a microscope.
1
\
yy,
a=
bias
a < = 2
om
1 os 3
eee
which row shows the correct locations for the placement of a graticule and a micrometer scale on
the microscope shown?
5 micrometer
| rate | meat
scale
a 1 2
b 1 3
cc 2 3
d 3 1

2 six organelles found in eukaryotic cells are shown.
1 2 3
—
grd
ss eh=
= \
cue  \»
no ee
wo, ©
oy, ms
cst a
bsf not to
scale
4 5 6
\.
° °
“= “an
which organelles are involved in the synthesis and secretion of a glycoprotein?
a 1,2,3and4 b 1,2,4and6 c 2,3and5 d 3,4,5and6

3 which cell structures can have mrna inside them?

1 chloroplast
2 mitochondrion
3 nucleus
4 rough endoplasmic reticulum

a 1,2,3and4

b 1, 2 and 3 only

c 2,3 and 4 only

d 3 and 4 only

4 a scientist carried out an experiment to separate the organelles in an animal cell by mass.

the scientist mixed the cells with a buffer solution which had the same water potential as the
cells. the cells were broken open with a blender to release the organelles.
the extracted mixture was filtered and then spun in a centrifuge at a high speed to separate the
heaviest type of organelle. these sank to the bottom, forming solid pellet 1.

liquid above

pellet

solid pellet

the liquid above pellet 1 was poured into a clean centrifuge tube and spun in the centrifuge at a
higher speed to separate the next heaviest type of organelle. these organelles sank to the
bottom, forming solid pellet 2.
this procedure was repeated twice more to obtain pellet 3 and pellet 4, each containing a single
type of organelle.
what is the main function of the type of organelle extracted in pellet 2?
a digestion of old organelles
b production of atp
c production of mrna
d _ synthesis of protein

5 which structures are found in palisade mesophyll cells and photosynthetic prokaryotes?

1 cell surface membrane
2 cellulose wall
3 ribosomes
4 chloroplasts

a 1,2,3and4

b= 1,2 and 3 only

c 1 and 3 only

d 2and4 only

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

7 which set of steps is the best method for conducting the emulsion test for lipids?
a_ add 2cm’ of water to the sample.
pour the water into a test-tube containing 2cm? of ethanol.
lipids are present if the mixture becomes cloudy.
b add 2cm? of ethanol to the sample and shake.
pour the ethanol into a test-tube containing 2.cm? of water and boil.
lipids are present if the mixture becomes clear.
c add 2cm* of water to the sample and shake.
pour the water into a test-tube containing 2cm? of ethanol and boil.
lipids are present if the mixture becomes cloudy.
d add 2cm’ of ethanol to the sample and shake.
pour the ethanol into a test-tube containing 2 cm? of water and shake again.
lipids are present if the mixture becomes cloudy.

8 a student was provided with a solution of carbohydrate. they removed two samples from the
solution and performed tests on each sample, as shown.
carbohydrate
solution
exe boiled with dilute
renedints test hydrochloric acid
benedict’s solution neutralised with dilute
remained blue sodium hydroxide
benedict's test
benedict’s solution
turned yellow
which statement explains the results?
a condensation reactions occur in sample two to release reducing sugar.
b_ glycosidic bonds in a polysaccharide have been broken to release reducing sugar.
c_ sample one shows that sucrose is present in the carbohydrate solution.
d_ the change in colour to a yellow solution shows that glucose is present.

9 which molecules contain at least two double bonds?
sucrose
collagen &py_

10 what describes cellulose?
a abranched chain of 1-4 a-glucose
ba branched chain of 1-4 b-glucose
c  anunreactive linear chain of 1-4 a-glucose
d anunreactive linear chain of 1-4 b-glucose

11. which part of the structure of haemoglobin carries oxygen?
a four polypeptide chains
b haem groups
c_ hydrogen bonds
d hydrophilic r groups

12 what is the maximum number of hydrogen bonds that can form between two single water
molecules?
a 1 b 2 cc 3 d 4

13 cyp3a4 is an important enzyme in the human digestive system where it is needed to break
down a range of different toxins. the activity of cyp3a4 has been shown to be reduced by
substances called furanocoumarins. furanocoumarins are found in some fruits and so dangerous
concentrations of toxins may develop in the human digestive system when fruits containing
furanocoumarins are eaten.

from the information provided, what can be concluded about molecules of the enzyme cyp3a4?
a they lower the activation energy of the toxin breakdown reactions.

b_ they bind specifically through the active site to a substrate found in some fruits.

c_ they change permanently when acted upon by furanocoumarin molecules.

d_ they resume normal activity when concentrations of furanocoumarins decrease.

14 a fixed volume and concentration of substrate and enzyme were mixed. all other variables were
kept constant. the enzyme-catalysed reaction was left until it was complete.
which graph shows how the rate of reaction changes with time?

a b
rate of rate of
reaction reaction
0 0
0 time 0 time
cc d
rate of rate of
reaction reaction
0 0
0 time 0 time

15 which molecules in cell surface membranes are typically involved in cell recognition?
[| erotstert | ateotnits | ateopoens | phospho
a v v x x key
b jv x x v j = involved
cc x v v x x = not involved
d x x v v

16 what can increase the fluidity of the cell surface membrane?
1 single bonds between carbon atoms in the fatty acid chains
2 cholesterol
3 longer-chained fatty acids
a 1,2and3 b 1and3only c 2and3only d = 2only

17 the three main factors that affect the rate of diffusion across a membrane can be expressed by
the relationship shown.
ee ' surface area x concentration difference
rate of diffusion is proportional to ———@—————_"————
thickness of membrane
which changes in the factors would result in the rate of diffusion doubling?
1 surface area has doubled.
2 concentration difference has halved.
3 thickness of membrane has doubled.
4 thickness of membrane has halved.
a 1,2and4 b 1and3 c 1and4 only d 2and3

18 a student measured the time taken for complete diffusion of a dye into agar blocks of different
sizes which were suspended in the dye.
the results are shown.
/mm x mm x mm diffusion/s
5x5x5 6.2
10x 10 x 10 16.1
15x 15x15 34.5
5x 10x 15
what is the predicted time for complete diffusion of the dye into the agar block measuring
5mm x 10mm x 15mm?
a 62s
b 16.1s
c 345s
d- more than 34.5s

19 an experiment was carried out to investigate the effect of concentration of sucrose solution on
cells in a plant tissue.
a sample of plant tissue was cut into seven cylinders of equal length and diameter. the mass of
each cylinder was recorded.
each of the seven cylinders was put into a different sucrose solution concentration.
bung
test-tube
sucrose
solution
plant tissue
cylinder
after two hours, the cylinders were removed, blotted dry and reweighed. the percentage change
in mass of each cylinder was recorded.
the graph shows the results of this investigation.
ox | | | [ | j[ |
8
10 ni
| e. | | | | | |
in mass of plant 0 [. =
tissue cylinder i 0 0.1 0.2 0. 0.4 0.5 0.6 0.7
ot | |
at | | | [| [tn |
—20
concentration of sucrose solution/moldm*
which row explains the results if plant tissue cells were put in a sucrose solution of 0.45 moldm°?
water potential of the cytoplasm change in volume of the
of the cells at the start of the vacuoles of the cells at the end
experiment compared with the of the experiment, that were
water potential of 0.45moldm™ | initially placed in 0.45moldm~®
sucrose solution sucrose solution
a less negative decreased
b less negative increased
cc more negative decreased
d more negative increased

20 the diagram shows part of the organisation of a section of a dna molecule and the associated
histones, p and r, in prophase of mitosis.
p
)
r
which statement about the features labelled p, q and r during prophase of mitosis is correct?
a_ the coiled dna molecule forms q and wraps around histone r to form small clusters held in
place by histone p.
b the groups of histones, p, and its associated dna, q, move closer together as the
chromosome condenses around r.
c_ the histones p and r are made of protein around which the dna molecule, q, is wrapped so
that the dna molecule can fit inside the nucleus.
d_ the linked groups of histones p and r and the associated dna, q, form strands that fold
and twist together to form a chromatid.

21 how many copies of each dna molecule will be found in a cell at the start of the stages of the
mitotic cell cycle shown?
g, of —
| iige | othe
a i i
b 1 2
cc 2 1
d 2 2

22 one characteristic of dna is that it is a universal genetic code.
what is meant by a universal genetic code?
a_ all living organisms use the same triplet code for amino acids.
b_ ail dna triplets code for a different amino acid.
c_ not all dna triplets code for an amino acid.
d_ allliving organisms contain the same four nucleic acids.

23 which statement about mrna is correct?
a _itis a polymer made of nucleotides all joined with hydrogen bonds.
b_ each nucleotide subunit contains the sugar ribose.
c it always has an equal proportion of adenine and uracil.
d the mrna sequence is identical to the template strand of dna.

24 the diagram shows part of the process of translation.
z
x
pa
[ee
ar
nd
what are the names of the structures labelled x, y and z?
p| x | vy [| 2 |
a anticodon codon mrna
b anticodon codon trna
cc codon anticodon mrna
d codon anticodon trna

25 the dna triplets of genes are translated as amino acids or stop signals during protein synthesis.
the table shows some of these triplets.
amino acid
ata tyrosine
atg tyrosine
aca cysteine
acg cysteine
atc stop signal
acc tryptophan
what could be the effects of one substitution mutation in a triplet coding for tyrosine?
1 the triplet is translated as cysteine.
2 the triplet is translated as tryptophan.
3. the triplet is translated as tyrosine.
4 translation stops at this triplet.
a 1,2and3 b 1,2and4 c 1,3 and4 d 2,3and4

26 which row identifies cells with plasmodesmata?
eae em |
tube element cell element
a jv v v key
b v v x / = plasmodesmata present
cc v x v x = plasmodesmata not present
d x v v

27 which statements about the apoplast and symplast pathways are correct?
1. in the apoplast pathway, water molecules move through free spaces in the cellulose
cell walls of plant roots.
2 in the symplast pathway, water molecules diffuse through the cytoplasm and
plasmodesmata of cells.
3 water molecules travelling through plant tissue move by mass flow along the
apoplast pathway.
4 the casparian strip blocks the symplast pathway and forces all water molecules to
enter the cytoplasm of endodermis cells.
a 1,2,3and4
b 1,2 and 3 only
c 1 and 2 only
d 3and 4 only

28 where does water evaporate from during transpiration?
a intercellular spaces
b leaf surface
c mesophyll cell walls
d stomatal pores

29 the diagram shows the outline of three xerophytic leaves of the same type in three different
conditions, p, r and s.
layer y layer y layer y
p r s)
which description of the water potential of the cells in layer y is correct?
water potential of cells in layer y
ee

a higher than r and s lower than p and s lower than p

b higher than s lower than p higher than p

cc lower than r higher than s higher than r

d lower than r and s higher than p lower than p

30 the photomicrograph shows a transverse section of the leaf of a species of grass.
lo in
lox wee)
a
7 ee rr rsd
eae
gy >
the grass is specially adapted to grow in a dry habitat.
which row correctly explains how the features help the grass to grow in this habitat?
| | hair-like structures leaf shape
a increase internal humidity decrease external humidity
b decrease external humidity increase internal humidity
cc increase internal humidity increase internal humidity
d decrease external humidity decrease external humidity

31 which statement supports the theory of active loading of sucrose into companion cells?
a_ the ph decreases in the cell wall of the companion cells compared with the cytoplasm.
b_ the ph decreases in the cytoplasm of the companion cells compared with the cell wall.
c_ the ph decreases in the companion cells and sieve tube elements.
d_ the ph decreases in the sieve tube elements compared with the companion cells.

32 which properties of water are essential for its role in the transport of blood in mammals?
[seas [sm
of vaporisation substances
a v x key
b x v ¥ = essential
cc v v x = not essential
d x x

33 the diagram shows some of the events that happen between the plasma and the red blood cells
in the circulatory system.
plasma red blood cell
1 1 + h,o
h,co3
4 pa \
2 3 ——» hb
4
2
what do the numbers 1, 2, 3 and 4 represent?
pot ot | 2 fos fs
a cl hco; h* co,
b co, hco” h* cr
cc hco; om co, h*
d co, h* hco;" cl"

34 the diagrams show the valves in the heart when viewed in cross-section from above at different
stages in the cardiac cycle.
semilunar valve atrioventricular valve
diagram 1 diagram 2
which stages in the cardiac cycle are shown?
diagram 1 diagram 2

a diastole ventricular systole

b atrial systole diastole

cc ventricular systole diastole

d diastole atrial systole

35 where are squamous epithelial cells found in the human gas exchange system?
[tastes | bronchus [aveous |
a jv j jv key
b v x v v = found
cc x v x x = not found
d x x v

36 which statement about gas exchange between air in the alveoli and blood in the pulmonary

capillaries is correct?

a_ the oxygen concentration in the capillaries leaving the pulmonary artery is higher than the
oxygen concentration in the alveoli.

b_ gases must diffuse across the endothelium of the pulmonary capillaries and the endothelium
of the alveoli.

c_ the elastic fibres in the alveoli walls allow the alveoli to expand to increase the surface area
available for diffusion into the pulmonary capillaries.

d_ breathing out reduces the carbon dioxide concentration gradient between the blood in the
pulmonary capillaries and the air in the alveoli.

37 the average thicknesses for some structures in the human respiratory system are shown.
ea
structure thickness of
structure/nm
human cell membrane 5
cytoplasm of alveolar wall cells 190
cytoplasm of capillary wall cells 90
tissues between alveolar wall and capillary wall 300
a molecule of oxygen is in the alveolar air space next to the wall of the alveolus.
what is the shortest distance that the molecule needs to diffuse from its current position to the
haemoglobin that completely fills a red blood cell in the nearest capillary?
(assume that the red blood cells touch the walls of a capillary.)
a 595nm b 600nm c 605nm d 610nm

38 the statements refer to the disease tuberculosis (tb).
1 the pathogen is not accessible to the immune system.
2 the bacterial pathogen reproduces slowly.
3 the pathogen is not very sensitive to antibiotics.
which statements explain why antibiotic treatment for tb takes a long time?
a 1,2and3 b tand2only c_  1only d 2and 3 only
turn over for questions 39 and 40.
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39 the average sizes of some pathogens are shown.
average size
—
hiv particle 100
mycobacterium tuberculosis 3000
plasmodium 20000
vibrio cholerae 1500
one type of air filter has been shown to be effective at preventing any pathogens of 1m or
larger from entering the air system of a room.
based on their size and mode of transmission, which diseases would the air filter prevent from
entering the air system of a room?
: ie tb malaria cholera
infection
a x v v v key
b x x v v v = prevented
cc jv x x x x = not prevented
d x v x x

40 a successful vaccination programme provides a level of immunity where the majority of a
population is protected.
there are several factors that can affect the success of a vaccination programme.
which row correctly shows the factors that can affect the success of a vaccination programme?
frequent mutation of vaccination from pathogen is able to | booster vaccinations
the pathogen eight weeks old invade t-cells needed frequently
a v v x v
b v x v v
cc x v v x
d jv x v x
key
j = affects
x = does not affect

Solve 9700_s23_qp_12