biology

1 an eyepiece graticule can be calibrated using a stage micrometer.
what is the correct reason why an eyepiece graticule is calibrated?
a aneyepiece graticule can be used to make measurements.
b_ aneyepiece graticule is magnified by the objective lens.
c_ aneyepiece graticule magnifies the specimen.
d_ aneyepiece graticule makes comparisons.

2 the image is an electron micrograph of a typical eukaryotic cell.
li ee gee ae ya ee eer ee)
ont 22 py: a 24 a tene es ee
bot ee co eo os
oe a : :
es ey he
“el ae pegs : ae
ee oe
ly wo | pees boer se
what can be concluded about the eukaryotic cell from the electron micrograph?
a_litis an animal cell because it does not have a cell wall.
blt is an animal cell because it contains a permanent vacuole.
c_itis a plant cell because it contains many chloroplasts.
d_itis a plant cell because it contains many lysosomes.

3. which features are found in typical eukaryotes and also in typical bacteria?
can respire
messenger rna ;
binds to 80s contain
ribosomes circular dna

4 which type of cell will have the highest proportion of its volume taken up with cell structures
bound by a single membrane?
a ciliated epithelial cell
b goblet cell
cred blood cell
d companion cell

5 what causes the phosphate heads of phospholipids to become polar?
a_ the phosphate heads are joined to water molecules by hydrogen bonds.
b_ the phosphate heads are insoluble in water.
c_ the phosphate heads become ionised in water.
d_ the phosphate heads are joined to water molecules by covalent bonds.

6 which statements describe features of cellulose that adapt it for its function in plant cells?
1 three cellulose molecules coil around each other to form a triple helix structure.
2 many hydrogen bonds form between adjacent cellulose molecules.
3 covalent bonds form between adjacent cellulose molecules.
a 1,2and3 b tand3only c 2and3o0nly d 2only

8 what cannot occur as a result of a condensation reaction?
a breaking of a glycosidic bond
b_ formation of a disaccharide
c_ joining together of two amino acids
d production of a molecule of water

9 which fact about the quaternary structure of proteins is correct?
a consists of four polypeptides
b_ depends on the presence of metal ions
c_ depends on the primary structure of the polypeptides
d_ is made of a and f polypeptides

10 the diagram shows different molecules in a solution.
p
q
s r
ss
which statement could explain what happens when some of the molecules are mixed together?
a molecule p forms an enzyme-substrate complex with the non-competitive inhibitor
molecule q.
b_- molecule q binds to molecule p, increasing the activation energy.
c molecules r and s bind to the active site of molecule p.
d molecules s and r are the products of the breakdown of molecule p.

11 the effect of substrate concentration on an enzyme-catalysed reaction was measured in three
different conditions:
e without an inhibitor
e with a competitive inhibitor
e with a non-competitive inhibitor.
the graph shows the results.
1
2
rate of
reaction 3
substrate concentration
which row is correct?
‘ with a with a
without an oa =
inhibitor competitive non-competitive
inhibitor inhibitor
a 1 2 3
b 1 2 2
cc 3 1 2.
d 3 2 1

12 which aspect of enzyme activity can be compared by the michaelis-menten constant?
a activation energy of a reaction with or without an enzyme
b affinity of different enzymes for their substrates
c affinity of an enzyme at different substrate concentrations
d maximum rate of reaction (vmax) at different temperatures

13 the number of substrate molecules one enzyme molecule can convert to product in a second is
called the turnover number. this number is obtained when all conditions are optimum for the
specific enzyme-catalysed reaction.

turnover number
enzyme is!
catalase 2800000
carbonic anhydrase 600 000
phosphatase 971
protease 100
how many times faster at converting substrate to product is catalase compared to phosphatase?
a 29 b 288 c 2884 d 28836

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

block1 3mmx3mm~x 3mm
block2 8mmx8&mmx 8mm
block3) 11mmx 11mm~x 11mm
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 0.5:1.0 4 1.33:1.0 11 1.83:1.0 13
b 0.5:1.0 13 1.33:1.0 11 1.83:1.0 4
cc 2.0:1.0 4 0.75:1.0 11 0.55:1.0 13
d 2.0:1.0 13 0.75:1.0 11 0.55:1.0 4

15 the statements describe some events in the process of exocytosis of glycoprotein molecules.

1. membrane of the golgi body folds around glycoprotein molecules.
2. vesicle binds to and fuses with the cell surface membrane.
3 vesicle attached to microtubules moves through the cytoplasm.
4 secretory vesicle forms.

what is the correct order of events for exocytosis?

a 1545253

b 154532

c 25375154

d 4351532

16 four cylinders that were identical in size, a, b, c and d, were cut from potatoes that had been
stored for different lengths of time.
the cylinders were weighed, immersed in 10% salt solution for 45 minutes and then reweighed.
the percentage change in mass was then calculated.
which cylinder had a water potential similar to the 10% salt solution?
| i
change in mass

a -7.2

b -2.5

cc -0.9

d +3.4

17 the contents of a daughter cell are compared to the parent cell after one cell cycle.
which row is correct?

number of volume of length of
chromosomes cytoplasm telomeres
a increases remains the same decreases

b increases decreases remains the same

cc remains the same remains the same remains the same
d remains the same decreases decreases

18 a high-power photomicrograph shows a cell in a stage of mitosis.
the chromosomes are visible and lined up along the cell equator but there is no nuclear
envelope.
which stage of mitosis is shown by the photomicrograph?
a prophase
b- metaphase
c anaphase
d_ telophase

19 which statements about the cell cycle are correct?
1 the cell cycle includes interphase and mitosis.
2 dna replication takes place in interphase.
3  acell can remain in interphase for several months.
a 1,2and3 b 1and2only c 1and3only d = 2and3 only

20 a scientist stains the chromosomes of a plant cell with a fluorescent dye to observe the
telomeres.
this cell has 38 chromosomes.
how many telomeres will the scientist observe in one of the nuclei during telophase of mitosis?
a 38 b 76 cc 114 d 152

21 during the semi-conservative replication of dna, the double helix is unwound by an enzyme.
which diagram shows how the strands are copied?
a b
o s! 3. os
5! 5
dna 3! dna 3!
polymerase polymerase
lagging leading
strand strand
dna , dna ,
5! 3! ligase 5! 3 5! 3! ligase 5! 3
leading strand lagging strand
cc d
5 st 5 6!
3° 3
dna 5! dna 5!
polymerase polymerase
lagging leading
strand strand
dna , dna ,
3" b ligase 3! 5 3 6 ligase 3! 5
leading strand lagging strand

22 a transcription error results in the deletion of one nucleotide from the middle of a primary

transcript. mrna forms from the primary transcript.

which statement describes one possible effect of this deletion on the protein translated from this

mrna?

a the protein will be unchanged as the same amino acids can be coded by another codon
formed by the deletion.

b_ the tertiary structure of the protein is not affected as only one amino acid has been changed
by the deletion.

c only one amino acid has been changed by the deletion but this changes the quaternary
structure of the protein.

d the sequence of amino acids in the protein will be different as all the codons from the
deletion onwards are changed.

23 which statements correctly describe the process of translation?
1 the nucleotide sequence on an mrna molecule is used to produce a specific
amino acid chain.
2  asection of dna is copied into an mrna molecule by rna polymerase.
3 a polypeptide is produced because anticodons on trna molecules attach to mrna
codons through peptide bonds.
a 1and2 b 1and3 cc 1only d 2and3

24 a molecule of mrna was used in translation. part of its sequence is shown.
gau cug uaa cgg

there were no introns present in the section of dna that was transcribed to make this mrna.
what is the sequence of the non-transcribed dna strand for this section?

a cta gac att gcc

b cua gac auu gcc

c gat ctg taa cgg

d gau cug uaa cgg

25 which properties of water are dependent on hydrogen bonding between water molecules?
p high latent heat solvent high specific
cohesion ean : ;
of vaporisation action heat capacity

a v v v x key
b v v x v v= dependent
cc v x v v x = not dependent
d x v v v

26 which substances in xylem tissue are impermeable to water and prevent the collapse of the
vessels?
[| impermesbeo water | proventcotapse |
a cellulose cellulose only
b cellulose lignin only
cc lignin cellulose only
d lignin cellulose and lignin

27 the electron micrograph shows a longitudinal section through phloem tissue.
aes ce
wr eo qe
4 aber see
ws ne
<i irn . atl
ga 3-o3
l “\ ¢ te
yn
p es ie) rt of me a ‘ *
4 as ro a ie
which student’s drawing of a sieve tube element is correctly drawn and labelled?
a b
mitochondrion
cell ie) \ 4
wall
ie)
o
0)
wh 0 a
o sieve o ) sieve
3 0 plate ar plate
‘.
c d
cell \ cell
wall ) wall
i)
cytoplasm @ o cytoplasm
-  @
0 a r no sieve
sieve a0 plate
se plate eo
o mitochondrion

28 carrier proteins in the cell surface membranes of companion cells are involved in the transfer of
assimilates to phloem sieve tubes. the diagram represents the use of two types of carrier protein
in this process.

x ¥ key
x x x x y c) pump
x x x ¥ companion
t rt

cell surface all eyteplaato oe fes p oren
membrane
what are the substances labelled x and y?
pf x

a h* ions sucrose

b h* ions glucose

cc sucrose h* ions

d glucose h* ions

29 the diagram shows pressure changes during two cardiac cycles.
which arrow indicates atrial systole?
a
20 /
i \ d wy n
if \ / \
i 1 / | \
i | i \
| 1 | \
| | | '
pressure \ | \
ikpa 10 '
| | i
b | :
ic ' i 1
i | | \
| \ , :
0 4:27 et “en ccacatl™ wa see
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
time/s

30 an irregular heartbeat may be the result of ineffective electrical stimulation of the atria.
which area of the heart could be damaged, causing this irregular heartbeat?
a atrioventricular node
b~ septum
c_ purkyne tissue
d - sinoatrial node

31 the diagram shows the effect of three different concentrations of carbon dioxide on the oxygen
dissociation curve for human haemoglobin.
100
x x = partial pressure of
carbon dioxide: 3.0kpa
percentage
saturation of y = partial pressure of
haemoglobin carbon dioxide: 5.0kpa
with oxygen z = partial pressure of
carbon dioxide: 7.0kpa
0
0 12
partial pressure of oxygen/kpa
which effect does increasing carbon dioxide concentration have on haemoglobin?
a_ it makes haemoglobin less efficient at taking up oxygen and less efficient at releasing
oxygen.
b_ it makes haemoglobin less efficient at taking up oxygen and more efficient at releasing
oxygen.
c_ it makes haemoglobin more efficient at taking up oxygen and less efficient at releasing
oxygen.
d_ it makes haemoglobin more efficient at taking up oxygen and more efficient at releasing
oxygen.

32 which reactions will be taking place in blood in a capillary that is next to an alveolus?
1 hb + 40, > hbog key
2 h20 + coz2 > hco; hb = haemoglobin
3. h2co3; > h* + hco;
a 1tand2 b= 1 only c 2and3 d = 2only

33 which structure of the gas exchange system always contains cartilage?
a alveoli
b bronchiole
c capillary
d bronchus

34 exchange of carbon dioxide and oxygen occurs between air in the alveoli and blood in the
capillaries of the lung.
which partial pressures of the gases will allow gaseous exchange to occur?
sean co, in blood ein o> in blood
alveolar air 1kpa alveolar air kpa
/kpa /kpa
a 5.3 6.0 13.3 13.9
b 5:3 6.0 13.9 5.3
cc 6.0 5.3 13.9 5.3
d 6.0 5.3 13.3 13.9

35 the plan diagram shows a cross-section of a trachea.
which labelled tissue prevents the trachea from collapsing?
b
co yyy c
(ca,

36 which layers of cells does an oxygen molecule diffuse through when moving from an alveolus
into an alveolar capillary?
(| aveous | aeotr apiony
a squamous epithelium squamous epithelium
b endothelium squamous epithelium
cc squamous epithelium endothelium
d endothelium endothelium

37 bacteria may be classified according to differences in cell wall structure. the differences are
shown by using the gram stain.
the diagram shows part of a gram-positive bacterium and part of a gram-negative bacterium,
drawn to the same scale.
external environment
covcuoou ooo:
oq rrq”
morrie '
rk peptidoglycan layer
a com
gram-positive sooo;
bacterium rooooooooooo , .
periplasm (watery fluid
containing proteins)
ess cell surface membrane
cytoplasm
external environment
outer membrane made of
carbohydrate and lipid
gram-negative — j _ periplasm
been cucu tetas ls:
cou uooo oo, i
sesesasessase | — peptidoalycan layer
—________, — periplasm
ees fags surface membrane
cytoplasm
the antibiotic penicillin kills bacteria by inhibiting the synthesis of the cell walls during bacterial
cell growth.
which type of bacteria will be killed by penicillin more easily and why?
a gram-positive bacteria because the peptidoglycan layer is exposed to penicillin directly
b_ gram-positive bacteria because it has a thinner layer surrounding the cell membrane overall
c gram-negative bacteria because the thin peptidoglycan layer can be broken down faster
d gram-negative bacteria because there is more periplasm available, which gives a weaker
structure

38 which facts relate to the disease tb or its pathogen?

1 viruses change their antigens to a limited extent.
2  tbis caused by only one species of pathogen.
3 hiv/aids makes the bacterial infection worse.
4 the pathogen may be transmitted by ingestion.
5 the pathogen may be transmitted from animals.
6  multi-drug resistance occurs.

a 1,4,5and6

b 1,2and6

c 2,3and5

d 3,4,5and6

39 the events listed occur during the primary immune response to a specific pathogen.
1 activation of b-lymphocyte to produce plasma cells and memory cells
2 phagocytosis of invading pathogens by macrophages
3. t-helper cell activation and production of t-killer cells
4 expression of antigens on phagocyte cell surface
5 production and release of antibodies
which row identifies a correct sequence of events?
[ee rt]
a 5 1 2 4 3
b 2 4 3 1 5
cc 4 2 1 5 3
d 4 2 3 1 5

40 influenza is an infectious disease caused by a virus.
it is possible to have influenza more than once.
which statements explain why it is possible to have influenza more than once?
1 the viral antigens change as a result of mutations.
2 the immune system may be weak and make few b-memory cells.
3 untreated hiv infection has resulted in a low t-helper cell count.
a 1,2and3 b tand2only c tand3only d = 2and3 only

Solve 9700_s24_qp_13