biology

1. a light microscope is used to observe two structures that are 200 nm apart on the slide.
what is the actual distance between the two structures when the magnification is changed from
x40 to x400?
a 2um b 20um cc 200nm d 2000nm

2 accell is shown in the micrograph.
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which statement explains how it is possible to identify the type of microscope used to produce
the micrograph?
a the nucleus is visible, so an electron microscope was used.
b_ the endoplasmic reticulum is not visible, so a light microscope was used.
c chloroplasts are visible, so a light microscope was used.
d_ ribosomes are visible, so an electron microscope was used.

3 which statement supports the fact that mature plant cells contain organelles that carry out the
same role as lysosomes?
a arrange of hydrolytic enzymes can be found within mature plant vacuoles.
b_ glycogen, found within vesicles, can be hydrolysed to glucose molecules.
c double membrane-bound vesicles are formed from plant golgi bodies.
d_ vesicles, formed from the cell surface membrane, contain enzymes.

4 which cell structures may contain cisternae?

[oss [a [ear [eee
a v v v x
b jv x x v
cc x v v x
d x v x v

key

v= may contain cisternae

x = does not contain cisternae

5 the diagram shows some cell structures of one type of cell.
1
2
j 3

which labelled cell structures are present in typical eukaryotic cells and typical bacterial cells?
a 1,2,3and4

b 1,3,4and5

c 1,2 and 3 only

d 3,4 and 5 only

6 the diagram shows part of a collagen fibril made of collagen triple helices. the collagen triple

helices are linked to each other by one type of bond. this bond is labelled as x in the diagram.

scrllln_ pslllllnnsl

xx qol ldl lll collagen
\ fibril
slqlrllllllsz
collagen triple helix

what is bond x?
a covalent bond
b_ disulfide bond
c hydrogen bond
d peptide bond

7 the table shows some information about the polypeptides that make up haemoglobin.
total number of amino acid 141 146
residues in polypeptide chain
position of amino acid cysteine 104 93 and 112
in polypeptide chain
scientists studied the region of the b-globin polypeptide chain containing the amino acid cysteine
at position 93. they found that:
e this region faces outwards when no oxygen is attached to the haem group
e this region faces inwards when oxygen is attached to the haem group
e replacing cysteine with a different amino acid reduces the bohr shift.
what can be concluded from the information about cysteine in haemoglobin?
a more than 1% of the amino acids in one haemoglobin protein are cysteine.
b_ in a-globin, there is a cysteine closer to the end of the polypeptide chain with an unreacted
carboxyl group than in b-globin.
c the replacement of the cysteine at position 93 in b-globin decreases the affinity of
haemoglobin for oxygen at low ph.
d_ the binding of oxygen to the haem group causes the region of b-globin containing cysteine
at position 93 to become more hydrophilic.

8 which feature of glycogen distinguishes it from starch?
a_ all glycogen molecules are highly branched.
b_ all glycogen molecules are polysaccharides.
c_ all glycogen molecules contain a-glucose.
d_ all glycogen molecules contain 1,4-glycosidic bonds.

9 the diagram shows a biological molecule.
h h h h h
h ow h | h | h | h | h | h
pn err lr erie us
h—c—o cc cc | cc | cc | cc | cc
lh | aa | wa] a] a |
h h h h h h
h h h h h h h
soa le alaa
h—cc—o~ sey sor se) sar | ee | ee pe ee
lh | h | wa | a | aw | aw] a
h h h h h h h h
pepe pa ta fw |
0. h h h h h h h
di | bs, iw ig ic. ie. ic. |
h—c—o cc cc | cc | cc | cc | cc | cc
| ee |
h h h h h h h h
which molecules would be produced if this biological molecule was hydrolysed?
a amino acids and glycerol only
b_ amino acids, glycerol and water
c fatty acids and glycerol only
d fatty acids, glycerol and water

10 a mixture of glucose and starch solutions was placed in a length of dialysis (visking) tubing and
the tubing sealed. the tubing was then placed in a boiling tube containing distilled water. two
samples were immediately removed from this water (time 0 minutes) and tested with either iodine
solution or benedict's solution. this was repeated at 10 minute intervals for 30 minutes.

the iodine solution gave an orange-brown colour each time.
the table shows the results of the benedict's test.
po [| | w |
colour produced
by benedict's test
what may be concluded from these results?
1 the pores in the visking tubing are too small for a starch molecule to pass through.
2 glucose diffuses through the visking tubing down a diffusion gradient.
3 water diffuses into the visking tubing.
a 1,2and3 b 1and2only c tand3only d = 2and3only

11. which molecules are globular proteins?
1 amylase
2 haemoglobin
3 dna polymerase
a 1,2and3 b tand2only c t1and3only d 2only

12 the initial rate of a reaction catalysed by an enzyme was measured at various substrate
concentrations.
which graph shows the effect of a low concentration of non-competitive inhibitor on the reaction?
a b
initial rate - initial rate ra
of reaction} ofreaction |
substrate substrate key
concentration concentration aan = without
inhibitor
(e3 d —— = with
gpreetsisiesa _—— inhibitor
initial rate ri initial rate fa
of reaction] “ of reaction} |
substrate substrate
concentration concentration

13 gout is a type of arthritis in which small uric acid crystals form inside and around the joints. it
causes sudden attacks of severe pain and swelling.
the diagram shows how uric acid is formed from hypoxanthine catalysed by the enzyme
xanthine oxidase.
oo oo [e)
h h h
n n n
hn | xanthine oxidase hn xanthine oxidase hn | 0
r nn é ‘ a | nn j " a n
n h,o0 + o, h,o> ie) n h,o + o, h,o> o n h
hypoxanthine xanthine uric acid
gout can be treated using a drug called allopurinol which has a similar shape to hypoxanthine.
oh
n7 s77?
oe
zn
n h
allopurinol
what can be concluded from this information about how allopurinol prevents the formation of uric
acid?
a it binds to the active site of xanthine oxidase instead of hypoxanthine, resulting in reduced
production of uric acid.
b it binds to another part of xanthine oxidase and this changes the shape of the active site.
c_ it disrupts the hydrogen bonds within xanthine oxidase so it denatures and the active site is
no longer complementary to hypoxanthine and xanthine.
d_ it hydrolyses the peptide bonds within xanthine oxidase to change the shape of the active
site.

14 phospholipids are formed in a similar way to triglycerides.

a sample contained six phospholipid molecules.
e the molecular weight of a phosphate ion is 95gmol".
e the molecular weight of each individual fatty acid in this sample was found to be

282 gmo!".

e the molecular weight of glycerol is 92g mol.
e the molecular weight of water is 18g mol”.

what is the molecular weight of the sample in g mol‘?

a 2598 b 4182 c 4506 d 4830

15 which statements about phospholipids in cell surface membranes are correct?
1 fatty acid tails allow most ions to pass through the membrane.
2 hydrophobic tails point inwards facing each other.
3. all polar heads face the cytoplasm.
4 the phospholipids help with the flexibility of the membrane.
a 1,2and3 b tand3only c 2,3and4 d 2and4 only

16 in an experiment, pieces of onion epidermis are put into three different concentrations of sucrose
solutions, p, q and r. the pieces of onion are left for an hour and then examined using the low
power of a light microscope.

each diagram shows one cell from the epidermis that was placed in each of the sucrose
concentrations.
p q r

<>
what explains the appearance of cells in solution q?
a_ the concentration of solution q is equal to the concentration of the solutes in the cell sap.
b_ the cytoplasm has the same concentration of sucrose as solution q.
c_ the water potential of the cytoplasm is equal to the water potential of the vacuole.
d_ the water potential of the cell sap is equal to the water potential of solution q.

17 the electron micrograph shows rod-shaped bacteria.
‘ edy - ‘ % 7 age ’
ay nee ee . f ee a :
ae | les e ‘
gs ze ier uy 4
hig j o 2
et j | hi 4
wr pe hi; ‘ys i\
es le 1 ‘
<j t , | oe a, ( r
4 ° ae e> is bs '
ha = ‘
' fi fet! id .
le yj :
yy if hi j \ 4 i
he > q £
: “f eg + ies
_— j
f * _ é
the actual length of the bacterium is 2.0um and the diameter is 0.5um. assume that the
bacterium is cylinder-shaped.
what is the surface area to volume ratio of the bacterium?
a 3.0:1.0 b 5.0:1.0 c 8.0:1.0 d 9.0:1.0

18 chickens have 78 chromosomes in the nucleus of a body cell.
how many dna molecules are there in a chicken body cell at the start of prophase of mitosis?
a 46 b 78 cc 92 d 156

19 the photomicrograph shows cells undergoing mitosis.
eee ae
, & ) : >
x ia x

% é *
which statement describes what will happen next in cell x?
a_ chromatin coils up tightly and the nuclear envelope breaks down.
b chromosomes line up along the equator of the cell and attach to the spindle.
c_ sister chromatids move towards opposite poles, pulled by the spindle fibres.
d_ spindle fibres break down and the cell prepares for cytokinesis.

20 which processes occur in bone marrow cells that are in a mitotic cell cycle?
1 phosphate groups bind to adp molecules to form atp.
2 bonds form between nucleotides in a dna strand.
3 hydrogen bonds form between trna anticodons and mrna codons.
a 1,2and3 b 1tand2only c jiand3only d 2only

21 the enzyme telomerase prevents loss of telomeres after many mitotic cell cycles.
which cells need to transcribe telomerase enzyme?
1 stem cells
2 activated memory b-lymphocytes
3 helper t-lymphocytes secreting cytokines
a 1,2and3 b jiand2only c 1and3only d 2and3only

22 a polypeptide molecule contains the amino acid sequence:
glycine — leucine — lysine — valine.

the table shows dna triplets for these amino acids.

which trna anticodons are needed for the synthesis of this polypeptide?
a ccc gaa tit caa

b ccc gaa uuu caa

c ggg cuu aaa guu

d ggg cuu uuu guu

23 the diagram shows a section of a strand of dna.
§ =
which type of bond is labelled x?
a glycosidic
b_ hydrogen
c_ peptide
d_ phosphodiester

24 which row correctly describes cytosine?
number of hydrogen
ring structure bonds it forms with its type of base

complementary base

a double three purine

b double two pyrimidine

cc single three pyrimidine

d single two purine

25 during the production of protein molecules, only one strand from the dna double helix is used.
which name is given to the dna strand that is used to produce a new protein?
a non-transcribed strand
b_ leading strand
c_ template strand
d lagging strand

26 the diagram shows a longitudinal section of a phloem sieve tube with a companion cell.
where are the mitochondria located for the release of energy for cotransport?
[|
a
cc
y d

27 the diagram shows a phloem sieve tube element and a companion cell that are involved in
translocation of sucrose.
ooo
i
wx yz
0
o
ooo
which process correctly describes the translocation of sucrose through these cells?
a sucrose moves from y to z by active transport.
b_ protons move from y to z by active transport.
c_ protons move from z to y by diffusion.
d_ protons move from x to w by diffusion.

28 which types of molecules are cotransported into companion cells?
a monomers and disaccharides
b monomers and polysaccharides
c_ polymers and disaccharides
d_ polymers and monosaccharides

29 the diagram shows a section through the human heart.
@\\ ba
qo. |
ed»
y b
=
eo y)
y
which label is correct?
a_ pulmonary artery
b left ventricle
c right atrium
d aorta

30 the graph shows how the volume of the left ventricle changes during one cardiac cycle.
which point on the graph represents the start of atrial systole?
pl d
100-44" c t
ventricular
volume /cm? b
40
time

31. which statement is correct?
a_inared blood cell, co2 can combine with haemoglobin to form haemoglobinic acid.
b_ carbonic anhydrase is an enzyme that catalyses the reaction between co2 and h20.
c_ atthe lungs, carbon dioxide is released when carbonic acid and water react together.
d_ the greater the concentration of co; in the blood, the higher the affinity of haemoglobin for
oxygen.

32. which row is correct for an artery?

a smooth layer of collagen, elastic fibres collagen only
endodermis cells and smooth muscle

b smooth layer of elastic fibres and collagen and
endodermis cells smooth muscle only elastic fibres

cc smooth layer of collagen, elastic fibres collagen and
squamous cells and smooth muscle elastic fibres

d smooth layer of elastic fibres and collagen only
squamous cells smooth muscle only

33 which row shows the features of the gas exchange surface that increase diffusion of
carbon dioxide and oxygen?

concentration diffusion
gradient distance

a steep long

b steep short

cc shallow long

d shallow short

34 the electron micrograph shows some of the airways in the gaseous exchange system of an
insect and the respiring body cells that surround them.
respiring body cell
each trachea is a. «292m vweaat ay / tracheoles are
filled with air which ey ye~ ue «ary les byz narrow tubes which
enters through tiny jee : bie oa fann tom a wige
holes called spiracles. 7 bm out | yay ye “2 trachea. they lie
each tracheaisheld |g? ‘= | ay) / gf lf next to body cells
open by spiralsofa gg ¥ gg wy aay and gaseous
material called chitin. — = yo f ve . j), x of exchange ogcuis
ho oe sna bos by) across them directly
thy » 1 fy fi | g4 into respiring body
ey yc od ee ff cals.
which statements describe correct differences between the insect gas exchange system shown
in the electron micrograph and the human gas exchange system?
1 gas exchange occurs through the walls of the airways directly into respiring body
cells in insects but this does not occur in humans.
2 there are spirals of chitin in the walls of a trachea in insects to hold it open but not
in humans.
3 there is more than one trachea in the gas exchange system of the insect but only
one in humans.
a 1,2and3 b jiand2only c 2and3only d = 3only

35 which row is correct for the wall of the trachea and the wall of the bronchus?
. smooth goblet
cartilage
muscle cells

a v v v key
b v v x / = present
cc v x v x = not present
d x v x

36 a bacterial pathogen produces a protein that acts as a toxin. this toxin is harmful to humans.
scientists are developing monoclonal antibodies that can be used to detect the presence of the
toxin in the body so that early treatment can be given.

which statements describe steps in the development of these monoclonal antibodies?
1. the toxin protein is injected into a mouse and triggers mitosis of specific
b-lymphocytes.
2 antibodies are collected from the spleen of the mouse and fused with myeloma
cells.
3 a hybridoma cell produces many antibodies with a variety of different variable
regions.
a ‘1and2 b= 1only c 2and3 d = 3only

37 which statements are correct for penicillin?
1 it is harmful to prokaryotic cells.
2 it disrupts cell wall synthesis.
3. it becomes less effective with regular use.
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

38 why is passive immunity effective for only a short time?
a_ antibodies are rapidly broken down.
b_ antigens are rapidly broken down.
c memory cells soon die.
d_ phagocytes soon die.

39 which row is correct for the control or prevention methods for each disease?
ee ee
a vaccination chlorination of water vaccination
b chlorination of water contact tracing destruction of the vector
cc contact tracing destruction of the vector chlorination of water
d | destruction of the vector vaccination contact tracing

40 peptidoglycan is stained purple by the chemical crystal violet.
which cells would stain purple in the presence of crystal violet?
a _palisade mesophyll cells
b_ vibrio cholerae cells
c plasmodium falciparum cells
d_ endothelial cells

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