biology

1. which statement explains why it is necessary to use an electron microscope to see the cristae of
a mitochondrion?
a the magnification of the electron microscope is greater than that of the light microscope.
b the membranes of the cristae are separated by a distance greater than 200 nm.
c_ the resolution of a student microscope using daylight is too low.
d_ the wavelength of an electron beam is longer than the wavelength of light.

2 a prokaryotic cell which is 0.25um in diameter, is magnified 50000 times on an electron
micrograph.
how big will its diameter be in the electron micrograph?
a 1.25 x 10mm
b 1.25 x 10°mm
c 1.25 x 10'mm
d 1.25 x 107mm

3 when making measurements in experiments, which methods could have parallax errors?
1 using a calibrated eyepiece graticule to measure length
2 using a measuring cylinder to measure volume
3 using aruler to measure length of a shoot
a 1,2and3 b 1and2only c 1and3only d 2and3only

4 the diagram is a drawing from an electron micrograph of a typical animal cell.
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what is the function of the membrane system labelled x?
a lipid synthesis only
b protein synthesis and transport
c protein synthesis only
d protein transport only

5 the diagram is a drawing from an electron micrograph of a typical animal cell.
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where would nucleic acid be found?
a 1,2and3 b 1and2only c t1and3only d = 2and3only

6 the diagram shows some similarities between chloroplasts, mitochondria and_ typical

prokaryotes.
which row is correct?
ee

a chloroplasts circular dna mitochondria linear dna prokaryotes

b mitochondria | 70s ribosomes | chloroplasts linear dna prokaryotes

[e mitochondria linear dna chloroplasts | 70s ribosomes prokaryotes

d prokaryotes 70s ribosomes | mitochondria | 70s ribosomes | chloroplasts

8 which words correctly complete the description of amylose?
the ......1...... amylose is a ......2...... made up of ......3...... of the ......4...... glucose.
a
a macromolecule monomer polymers disaccharide
b macromolecule monomer polymers monosaccharide
cc polysaccharide polymer monomers disaccharide
d polysaccharide polymer monomers monosaccharide

9 which statements about glycosidic bonds are correct?
1 they occur by condensation reactions between the oh groups of two molecules.
2 they occur only between glucose molecules.
3 the bonds can only be formed between carbon 1 and carbon 4 or carbon 1 and
carbon 6 of adjacent molecules.
4 hydrolysis of the bonds releases energy.
a 1,2and3 b iand4 c 2and4 d 3and4

10 what is the general formula for glycogen?
a (csh100s)n b  (c5h1006)n c  (c6h1005)n d  (c6h1206)n

11 which statements are correct?
1 in a triglyceride molecule the bonds between the fatty acids and the glycerol
molecule are called ester bonds.
2 triglycerides are formed by a condensation reaction between the hydroxyl group of
a fatty acid molecule and one of the carboxyl groups of the glycerol molecule.
3. triglycerides are insoluble in water because the fatty acid carbon chain is non-polar.
a 1,2and3 b 1and2only c t1and3only d = 2and3only

12 the table shows the diameter of some atoms when they form bonds.
single bond | double bond
atom
/nm /nm
h 0.060 -
oo 0.132 0.110
n 0.140 0.120
cc 0.154 0.134
the approximate length of the amino acid shown was estimated using the figures in the table.
r o
a— 1 7 ie
h oh
+
0.7nm
what would be the approximate length of a dipeptide formed using this amino acid?
a 0.9nm b 1.2nm c 1.4nm d 1.7nm

13 which statement about the typical modes of action of a competitive inhibitor and a

non-competitive inhibitor is correct?

a_ competitive inhibitors can bind to alternative (allosteric) sites of an enzyme, non-competitive
inhibitors have an irreversible effect on the enzyme.

b competitive inhibitors have exactly the same shape as the substrate, non-competitive
inhibitors can have any shape.

c competitive inhibitors may be used to regulate enzyme activity, non-competitive inhibitors
have no functions in enzyme regulation.

d competitive inhibitors will not alter v,,.,, non-competitive inhibitors will reduce v max.

14 some animals produce antimicrobial proteins which protect them from pathogens. these proteins
could be used to kill human pathogens, however when used as a medicine they are broken down
by protein-digesting enzymes.

replacing one of the amino acids found in the protein with one that had been synthesised in the
laboratory resulted in a modified protein that was not broken down.
what could explain why this modified protein was not broken down by the protein digesting
enzymes?

1 the modified protein has a different tertiary structure to the original protein.

2 the modified protein is not complementary in shape to the enzyme’s active site.

3 the modified protein is unable to induce a fit with the protein digesting enzyme.
a 1,2and3 b 1and2only c 2and3only d 2only

15 aninvestigation was carried out on the effect of temperature on an enzyme-catalysed reaction.
the enzyme and its substrate were initially placed into separate test-tubes and raised to the
temperature required. they were then mixed and placed into four tubes a, b, c and d.

these tubes were incubated for the time and at the temperature stated. the mass of the product
formed was then measured.
in which tube was the rate of reaction highest?
incubation incubation mass of
time/s temperature /°c product/ ug

a 30 25 2.5

b 30 45 5.0

cc 600 25 32.0

d 600 45 10.0

16 in an experiment the proteins in the cell surface membrane of a living cell were labelled with a
fluorescent dye.
a small area of the membrane was observed using a microscope. a laser was then used to
permanently destroy the fluorescence of the dye molecules in this field of view.
the fluorescence in this field of view was later seen to return.
what does this experiment show?
a_ proteins are found only on the outer surface of cell surface membranes.
b_ proteins in the outer layer of a bilayer do not penetrate into the inner layer.
c_ proteins move freely in the phospholipids of a bilayer.
d_ the cell surface membrane of the cell is a bilayer.

17 in plants adapted to cold conditions, their cell surface membranes change as the weather gets
colder, allowing the plants to carry out exocytosis.
which change occurs in their cell surface membranes?
a adecrease in the ratio of proteins to saturated phospholipids
b  adecrease in the ratio of unsaturated phospholipids to saturated phospholipids
c_anincrease in the ratio of proteins to unsaturated phospholipids
d_anincrease in the ratio of unsaturated phospholipids to saturated phospholipids

18 which statement describes endocytosis?
a movement across a membrane against the concentration gradient and requiring energy
b movement across a membrane down the concentration gradient using a carrier molecule
c movement across a membrane into a cell using a vesicle and requiring energy
d movement across a membrane using a vesicle and requiring no energy

19 an indicator is colourless in acid and pink in alkali.
in an experiment a petri dish of agar was prepared using an acidic solution of this indicator.
a disc of agar 1cm in diameter was removed from the centre to create a well.
a white card showing circular marker lines 1 cm apart was placed underneath the petri dish.
14cm? alkali solution was put into the well in the agar and a stop-watch was started.
a circular disc of pink colour appeared and spread through the agar. it reached the first marker
line in a short time but took longer to reach the second marker line and a very long time to reach
the third marker line.
what explains these observations?
a facilitated diffusion of alkali solution
b facilitated diffusion of the indicator
c _ simple diffusion of alkali solution
d _ simple diffusion of the indicator

20 how many copies of each dna molecule will be found in a cell at each stage of the mitotic cell
cycle?
| i
a 1 4 1
b 1 2 2
cc 2 4 1
d 2 2 2

21 centromere, chromatids and telomeres are parts of a chromosome in a eukaryotic cell.
which row correctly describes these structures?
[| eentomere [gomes | tomers |
a binds the two sister contains histone proteins protects the tips of each
chromatids of a and a molecule of chromatid from shortening at
chromosome together double-stranded dna each mitotic division
b site of attachment of contains histone proteins prevents the genes nearest
spindle microtubules and a molecule of the ends of each chromatid
single-stranded dna from being lost
cc site of production of contains a molecule of contains dna with many
spindle microtubules double-stranded dna with no repeats of short base
associated histone proteins sequences
d splits at metaphase contains a molecule of ensures that when dna is
of mitosis single-stranded dna with no replicated, the ends of the
associated histone proteins molecule are included

22 which bases found in nucleic acids are purines?
a adenine and cytosine
b guanine and adenine
c_ thymine and cytosine
d_ uracil and guanine

23 a length of double-stranded dna contains 120 nucleotides and codes for a section of a
polypeptide.
what is the maximum length of this section of a polypeptide?
a 20 amino acids
b 40 amino acids
c_ 60 amino acids
d 120 amino acids

24 four students were asked to suggest a set of four labels to add to a plan diagram of a transverse
section of a dicotyledonous leaf.
which student suggested a correct set of labels?
| | label 4 label 2 label 3 label 4
a lower phloem spongy palisade
epidermis mesophyll mesophyll
b phloem sieve upper spongy xylem vessel
tubes epidermis mesophyll elements
[e spongy endodermis xylem vessel palisade
mesophyll elements mesophyll
d waxy cuticle xylem companion spongy
cells mesophyll

25 photomicrograph x shows a transverse section through a typical stem. photomicrograph y
shows a longitudinal section through one type of cell shown in photomicrograph x.
which letter represents the cells from photomicrograph y?
photomicrograph x photomicrograph y

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26 by which process would water rise up through xylem vessels in a plant root when the shoot has
been removed?
a capillarity, root pressure and transpiration pull
b_capillarity and root pressure only
c_capillarity and transpiration pull only
d root pressure only

27 which changes occur to the water potential and the volume of liquid in the phloem sieve tube
element when carbohydrate is moved into a sink?
water potential volume of liquid
of the sieve of the sieve
tube element tube element
a lowers decreases
b lowers increases
cc raises decreases
d raises increases

28 the graph shows the diameter of a tree trunk over time.
diameter of
tree trunk
12:00 00:00 12:00 00:00 12:00
time of day

which statement explains these changes?

a_ cohesive tension forces increased during the day.

b columns of water break up during the day.

c_ mass flow of sucrose decreased during the day.

d_ root pressure increased during the day.

29 what is found in all blood vessels, lymph and tissue fluid?

1 carbon dioxide
2 glucose
3 white blood cells
4 antibodies

a 1,2,3and4

b 1,2 and 3 only

c 1,3 and 4 only

d 2and4only

30 which reactions will be taking place in blood that is passing through active tissues?

1 hbosg — hb + 40,
2 hbog + h* — hhb + 40,
3 hco; + h* — h2co3
4 ho + co. > hco;

a 1,2,3and4

b 1,2 and 4 only

c 1,3 and 4 only

d 2and3only

31 the graph shows the percentage saturation of haemoglobin with oxygen at a range of partial
pressures of oxygen and at two partial pressures of carbon dioxide.
one curve is at the partial pressure of carbon dioxide in the lungs and the other curve at the
partial pressure of carbon dioxide in the liver.
100 l
m
percentage
saturation of
haemoglobin
with oxygen
j
0
0) partial pressure
of oxygen/kpa
which points on the curves correspond to the percentage saturation of haemoglobin at the lungs
and at the liver?
a landj b landkk c mand j d mandk

32 a person moves from sea level to live at a high altitude.
ie three months living at high altitude, which change would be found in this person when at
rest?
a _ increased volume of blood per heartbeat
b increased breathing rate
c_ increased heart rate
d_ increased mass of red blood cells

33 the diagram shows three of the features found in tissues of the gas exchange system.
ciliated goblet
epithelium cells
which structures of the gas exchange system could be represented at position x in the diagram?
1 bronchiole
2 trachea
3. bronchus
a 1,2and3 b 1and2only c tand3only d = 2and3only

34 chronic obstructive pulmonary disease (copd) includes bronchitis and emphysema.
which row shows the effects of bronchitis?
[[hetercets [ broncos | infeston _ |

a destroyed inflamed absent
b destroyed narrowed present
cc increased scarred present
d increased stiffened absent

35 which factors affect the distribution of the disease malaria?
1 draining swamps
2 vaccination
3. antibiotics
4 migration of people due to conflict
5 climate
a 1,2and4 b 1,4and5 c 2,3and5 d 3,4and5

36 which diseases cannot be treated with antibiotics?
1 cholera
2 hiv/aids
3 measles
a 1,2and3 b 1and2only c 1and3only d = 2and3only

37 a west african country introduced a measles vaccination during a measles epidemic.

later, it was realised that vaccinated children were more likely to survive childhood than

unvaccinated children, even when there were no measles epidemics.

the vaccine had given the children some protection against other pathogenic infections.

which statement could account for this extra protection?

a_ b-lymphocytes produced memory cells which gave the children passive immunity to these
infections.

b memory cells produced plasma cells which secreted anti-measles antibodies that bound to
antigens that closely resembled measles antigens.

c memory cells produced plasma cells which secreted anti-measles antibodies that bound to
any antigen.

d_ t-lymphocytes produced memory cells which gave the children natural immunity against
these other infections.

38 which graph shows the changes in antibody concentration following a second exposure to the
same infection?
1000
antibody 100
a concentration
/arbitrary units 10
1
0 10 20 30 40 50 60 70 80
{ 1 time/days
first exposure second exposure
1000
antibody 100
b concentration
/arbitrary units 10
1
0 10 20 30 40 50 60 70 80
{ i time/days
first exposure second exposure
1000
antibody 100
(es concentration
/arbitrary units 10
1
0 10 20 30 40 50 60 70 80
{ { time/days
first exposure second exposure
1000
antibody 100
d concentration
/arbitrary units 10
1
0 10 20 30 40 50 60 70 80
{ { time/days
first exposure second exposure

39 where are antigens found?
[se |
of pathogen plasma
a v jv key
b v x v= antigens found
cc x v x = antigens not found
d x x

40 whooping cough is a highly infectious disease of the gas exchange system, caused by the
bacterium bordetella pertussis.
which method provides protection to infants against whooping cough and reduces the chance of
developing this disease later in life?
a ashort course of more than one type of antibiotic
basix month course of one type of antibiotic
c injections of antibody specific to bordetella pertussis
d injections of dead bordetella pertussis bacteria

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