biology

1. which equation for calculating the actual size of a specimen, a, or image size, i, or magnification,
m, is correct?
a a=m=i b a=ixm c i=m+a d m=i+a

2 one of the smallest viruses is the polio virus, which has a diameter of approximately 30 nm.

in 2003, the mimivirus was discovered which has a diameter of approximately 680 nm.
in 2013, the pandoravirus was discovered which has a diameter of approximately 1000 nm.
which row correctly matches a cell structure with a virus that has a similar approximate size?
[poe vies [minis | pandoravies |

a lysosome nucleolus nucleus

b nucleolus lysosome mitochondrion

cc nucleolus mitochondrion lysosome

d ribosome lysosome mitochondrion

3 which cell components are present in all prokaryotic cells?
cell surface endoplasmic
cell wall : flagellum

membrane reticulum
a v v x v key
b v v x x v = present
cc v x v x x = not present
d x v v v

4 the electron micrograph shows part of an animal cell.
ey rak,
by ae bs ee 5 of wy
me oe ss /))
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nis aol paw ene ne pe nn
be es _ nig ae” a8 ns ey
ee | re
ee ee ee gp
k box ee " ar ee
nsu eae i east
ik oa)!
le ee va ae
win sls
ns ore valli seer rna
what will be synthesised in large quantities in this cell?

1 atp

2 glucose

3 rna

a 1,2and3 b jiand3only c 1 only d 2only

5 mitochondria are thought to have evolved from prokaryotic cells that were ingested by an
ancestral cell.
which feature have the prokaryotes lost during their evolution into mitochondria?
a cell wall
b circular chromosome
c_ endoplasmic reticulum
d_ ribosomes

6 which statement is correct?
a avvirus is composed of a protein coat which may surround rna or dna.
b_ eukaryotic plant cell walls contain peptidoglycans in addition to cellulose.
c_ plasmodesmata and centrioles are found in all plant cells.
d_ prokaryotic cells contain 80s ribosomes which they use to manufacture proteins.

7 a student carried out four tests for biological molecules on a sample of milk.
the tests and their results were as follows.
e heating to 80°c with benedict's solution gave a brick red colour.
e adding biuret solution gave a purple colour.
e adding iodine solution gave an orange colour.
e boiling with acid, followed by neutralisation, then heating to 80°c with benedict's
solution gave a brick red colour.
which biological molecules must be present in the milk?
1 non-reducing sugars
2 protein
3. reducing sugars
4 — starch
a 1,2and3 b 1tand2only c 2and3only d 3and4

8 which features adapt a cellulose molecule for its function?
1 long chains of glucose molecules coil into a helix.
2 many hydrogen bonds form between adjacent chains.
3 it is insoluble in water.
a 1,2and3 b tiand3only c 2and3only d 2only

9 two disaccharides are maltose and sucrose. maltose is formed from two molecules of glucose,

whilst sucrose is formed from fructose and glucose.
which row shows the molecular formulae of the two disaccharides?
[[ratose | sueose

a cy2h 22014 cy2h22014

b cy2h22014 cy2h24012

cc cy2h24012 cy2h22014

d cy2h24012 ci2h24012

10 ie diagram shows the structure of the polysaccharide chitin which is found in the cell wall of
ungi.
ch,
b=o
ch,oh i h ch,oh
i :— fe) o—t i i b— )
4 a a pe
i. — rl — ra i. — ral
4 h dere 4 h
o— i o=> !
on, bu,
which statements are correct for chitin and for cellulose?
1. the monomers are joined by 1,4 glycosidic bonds.
2 every second monosaccharide in the polysaccharide chain is rotated by 180°.
3 the polysaccharide contains the elements carbon, hydrogen, oxygen and nitrogen.
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

11 which row correctly matches the functional and structural features of cellulose, collagen,
glycogen or triglyceride?
molecules held
molecule function fibrous together by branched chains
hydrogen bonds
a cellulose support jv v x
triglyceride | energy source x x x
collagen strengthening v v x
cellulose support v x v
cc collagen strengthening v v jv
glycogen storage x x v
glycogen storage x v jv
triglyceride energy source x v x
key y=true x= false

12 a polypeptide has a number of amino acids (n).
how many peptide bonds and r groups (side chains) does this polypeptide have?
a n-—1 peptide bonds and n— 1 r groups
b  n-—1 peptide bonds and n r groups
c  npeptide bonds and n—1 r groups
d  npeptide bonds and n r groups

13 what are the features of triglycerides?
jess dange lower proportion
polar than water of hydrogen than
in carbohydrates
a v v x key
b v x v v=yes
cc x v x xx =no
d x x v

14 which of these statements describe the action of an extracellular enzyme?
1 synthesis of a polynucleotide in the nucleus during dna replication
2 digestion of macromolecules in the lumen of the small intestine
3. synthesis of atp molecules in the mitochondria
a 1and2 b 1and3 c 2and3 d = 2only

15 an experiment was carried out in which the enzyme lipase was used to hydrolyse a triglyceride.
the ph was recorded at regular intervals during the reaction.
the results are shown in the table.

0 7.0
2 6.2
4 5.6
6 5.1
8 4.7
10 46
12 46
14 46
at 14 minutes unreacted triglyceride was still present.
what explains the results after 10 minutes?
a_ the end-products acted as competitive inhibitors.
b_ the end-products acted as non-competitive inhibitors.
c_ the enzyme reaction had reached vmax.
d_ the tertiary structure of the enzyme had been lost.

16 which statement about the effect of substrate concentration on the activity of an enzyme is

correct?

a_ above a certain concentration of substrate an enzyme reaches its maximum rate of reaction.

b_ at high concentration of competitive inhibitor increasing the substrate concentration has no
effect.

c_ at high substrate concentration a non-competitive inhibitor no longer affects the enzyme
activity.

d_ the higher the concentration of substrate the faster an enzyme can catalyse a reaction.

17 which row shows a correct function of the components of the cell surface membrane?
| | phospholipids cholesterol glycoproteins
a | prevent the entry of regulates allow exchange allow cell-to-cell
non-polar molecules | permeability of the of ions communication
membrane between the cell and
its environment
b prevent the entry of stabilises the allow cell-to-cell provide sites
polar molecules membrane by communication of attachment
binding to water for hormones
molecules
cc regulate the prevents the entry allow exchange stabilise the
flexibility of protons of gases membrane by
of the cell between the cell and binding to water
membrane its environment molecules
d | regulate the fluidity stabilises the form channels for allow cell-to-cell
of the cell membrane over a polar molecules recognition
membrane range of
temperatures

18 the graph shows how the rate of entry of substance x into a cell changes as the concentration of

substance x outside the cell increases.

rate of entry of

substance x

concentration of
substance x outside the cell
the diagram shows part of a cell surface membrane.
1 2 3

which pathways could substance x use to enter the cell?
a i1and2 b 1 only c 2and3 d = 2only

19 the photomicrographs show cells in various stages of the cell cycle.
in which stage does semi-conservative replication of dna take place?
a b cc d

20 the diagram shows the structure of one chromosome.
1
2
which row is correct?
4 2 number of
dna strands
a centromere chromatid 2
b centromere telomere 4
cc chromatid telomere 2
d telomere chromatid 4

21 cancer cells may divide by far more divisions than other cells found in humans.
which statement about cancer cells is correct?
a they are able to synthesise the enzyme telomerase.
b_ they have a mutation in the telomeres so dna is not hydrolysed.
c_ they have dna polymerase so can replicate their dna without telomere loss.
d_ they increase the number of copies of repeated dna sequences in the telomeres.

22 what is the maximum number of hydrogen bonds in a length of dna containing 700
nucleotides?
a 350 b 700 cc 1050 d 2100

23 which statements concerning dna and rna are correct?

1 adenine and guanine are bases that have a double ring structure; cytosine, thymine
and uracil are bases with a single ring structure.

2 an adenine nucleotide from dna is the same as an adenine nucleotide from rna;
dna adenine pairs with thymine and rna adenine pairs with uracil.

3 the base pairing that occurs in a double dna helix and when rna is synthesised
during transcription is always according to the rule that a purine pairs with a
pyrimidine.

4 the two polynucleotides on a dna molecule run in opposite directions so that the
double helix formed has two strands that are parallel to each other.

a 1,2and3 b 1,2and4 c 1,3 and4 d 2,3and4

24 two sets of bacteria were grown using different types of nitrogen-containing growth media.
one set was grown in a medium containing the ‘heavy’ isotope of nitrogen, ‘°n, until all the dna
was labelled. the other set was grown in a medium containing the ‘light’ isotope of nitrogen, ‘4n,
until all the dna was labelled.
the dna from each set of bacteria was extracted and centrifuged. the diagram shows the
position in the centrifuge tubes of this dna.
dna with '4n
dna with '°n
bacteria with '°n labelled dna were transferred to a medium containing “4n and allowed to
reproduce once. the dna of the new generation of bacteria was extracted and centrifuged.
which tube shows the position of dna from this new generation of bacteria?
a b cc d

25 the diagram shows the nucleotide sequence of a small section of a gene which is transcribed.
gcgcgcggcgcg
the table shows the amino acids coded for by 10 mrna codons.
mrna codon amino acid
aag lys
acg thr
cgg cgc cgu arg
ccg pro
gcc gcg ala
ggc gly
ugc cys
what is the order 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 wvnat contributes to the movement of water through the xylem vessel elements?
a_ cohesion of water molecules through hydrogen bonding
bion movement followed by passive osmosis
c negative water potential in the xylem
d surface tension at the top of the plant

27 the diagram shows a xerophytic leaf in different conditions, p and q.
x
p q

which statements about the cells in layer x of the leaf in each of the conditions p and q are
correct?

1 less negative water potential in p than q

2 cells may be turgid in p and plasmolysed in q

3 cells less turgid in p than q

4  nonet diffusion of water into x in either p or q
a 1,2,3and4
b 1,2 and 4 only
c 1 and4 only
d 2and3 only

28 what are features that adapt root hair cells for efficient uptake of mineral ions?
1 alarge number of mitochondria
2 alarge number of protein carriers in the cell surface membrane
3 alarge surface area to volume ratio
a 1,2and3 b 1dand2only c tand3only d = 2and3only

29 the transverse sections of two plant organs are shown.
ss
q
©)
06 6 98 ) 1,"
g if
r
which pair of tissues contains proton pumps?
a qands b qandt c rands d randt

30 measurements of the stem of a young tree showed that the diameter varied slightly. it decreased

during the day and increased during the night.

which statement explains these observations?

a during the day, cohesion between water molecules and lignin in the walls of the xylem
vessels pulls the walls of the vessels inwards.

b_ during the day, the tension developed in a moving column of water molecules reduces the
pressure inside the xylem vessels, so that their walls move inwards.

c_ during the night, the adhesion of water molecules to the lignin in the walls of the xylem
vessels pushes the walls of the vessels outwards.

d_ during the night, the pressure of the column of water molecules adhering to one another
increases and pushes the walls of the xylem vessels outwards.

31 which statement about the human circulatory system is correct?
a_ blood passes twice through the heart in one complete circulation.
b_ blood, tissue fluid and lymph are all parts of the circulatory system.
c_ capillaries have the lowest blood pressure.
d_ veins in the circulatory system all carry deoxygenated blood.

32 the graph shows changes in the volume of the ventricles during the cardiac cycle.
p
volume
/arbitrary |
units |
| r |
i '
| ventricular diastole
atrial systole
systole
stages of the cardiac cycle
which valves open and close at p and r?
atrioventricular semilunar valve
valve at p atr
a closes closes
b closes opens
cc opens closes
d opens opens

33 haemoglobin can bind to carbon dioxide, carbon monoxide and oxygen.
1 carbon dioxide
2 carbon monoxide
3 oxygen
which gases share a binding site?
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

34 a good gas exchange system maintains a steep diffusion gradient, has a large total surface area
and a short diffusion distance.
which feature of the human gas exchange system helps to maintain a steep diffusion gradient?
a a large number of alveoli are present in each lung.
b_ alveoli walls contain elastic fibres allowing expansion.
c_ the air brought into the alveoli by ventilation is high in oxygen.
d_ the endothelium of the capillary wall is made of flattened cells.

35 which statement about bronchioles is correct?
a they have cartilage and ciliated cells.
b_ they have cartilage and elastic tissue.
c_ they have cartilage and muscle tissue.
d_ they have elastic tissue and ciliated cells.

36 in which regions of the human gas exchange system is the function of some types of cell directly
affected by tar in cigarette smoke?
a bronchioles and alveoli only
b_ trachea, bronchus, bronchioles, alveoli
c_ trachea and bronchus only
d_ trachea, bronchus and bronchioles only

37 what is the causative agent and method of transmission of smallpox?
‘ method of
causative agent ‘ae

transmission

a morbillivirus direct contact
b morbillivirus waterborne

cc variola direct contact
d variola waterborne

38 a scientist investigated the effect of an antibiotic on the treatment of cholera.
320 people suffering with cholera were split into two groups. one group was treated with an
antibiotic while the other group was not given antibiotics. both groups were given fluids
containing sugars and mineral salts (oral rehydration therapy).
the scientist recorded the number of days that each person suffered from diarrhoea.
the table shows the results.
mean time person had
treatment ‘
diarrhoea/days
antibiotic and oral rehydration therapy 3.2
oral rehydration therapy 5.3

what is the percentage decrease in the mean time that a person suffered from diarrhoea when
they were treated with the antibiotic?
a 39.6% b 60.4% c 165.6% d 252.4%

39 which sequence of events occurs during an immune response?

1 development of plasma cells
2 mitosis of b-lymphocytes
3. recognition of non-self antigens
4 — secretion of antibodies

a 2535451

b 254531

c 3515254

d 352514

40 an influenza vaccine can be made by growing the viruses in chicken eggs.
the viruses are extracted in liquid from the eggs and inactivated. the purified egg extract
containing the viruses is then used as the vaccine.
what is a side-effect of using this vaccine in some people?
a_ an auto-immune condition could occur.
b  animmune response to egg antigens could occur.
c_ the egg antigens could cause infections.
d_ the influenza viruses could cause infections.

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