biology

1. the diagram shows the ultrastructure of a typical animal cell.
which structure synthesises and transports lipids?
d
qo
s o.| @®
yo me.
eg 0,° ce
@ it 9 a
\e
o 7°
cc

2 a\light microscope is used to observe two structures that are 200nm apart.
how far apart are the structures when the magnification is changed from x40 to x400?
a 2um b 20um cc 200nm d 2000nm

3 the diagram shows a stage micrometer scale viewed through an eyepiece containing a graticule.
the small divisions of the stage micrometer scale are 0.1mm.
0 10 20 30 40 50 60 70 80 90 109
the stage micrometer scale is replaced by a slide of a plant cell.
ee if
c oe.” lad ‘
ass 2 aa
0 10 20 30 40 50 60 70 80 90 100
what is the length of the nucleus in the plant cell?
a 0.8mm b 8um c 25um d 200um

4 some features of cells are listed.
1 cytoplasm
2 cell surface membrane
3. ribosomes
which features are found in both animal and prokaryotic cells?
a 1,2and3 b tand2only c tand3only d 2and 3 only

5 which size of ribosomes is found in chloroplasts?
a 60s b 70s cc 80s d 90s

6 in which of these organelles is atp synthesised?
golgi body
fs mitochondrion
chloroplast ll

8 the table shows some information about carbohydrate polymers.
which row describes amylose?
a-1,4 a-1,6 shapeof
glycosidic glycosidic ir
bonds bonds
a v jv branched key
b v x helical jv = present
cc x v branched x = absent
d x x helical

9 which row about a-glucose and b-glucose molecules is correct?
carbon atom on which cellulose contains both
the oh position is different molecules
a 1 no
b 1 yes
cc 4 no
d 4 yes

10 some of the molecules found in animal tissues are grouped into three lists.
1 glucose, cholesterol, triglycerides, water
2 glycogen, antibodies, adenine, phospholipids
3 haemoglobin, carbon dioxide, mrna, monosaccharides
which lists include one or more molecules that always contain nitrogen atoms?
a 1,2and3 b tand2only c t1and3only d 2and3only

11 haemoglobin consists of two a chains and two £ chains. approximately 5% of all humans have
one amino acid in the b chain that has been changed, affecting the structure and stability of
haemoglobin.

which of the levels of protein structure could be changed in the haemoglobin of these humans?
a primary only

b primary and quaternary only

c primary, secondary, tertiary and quaternary

d_ secondary, tertiary and quaternary only

12 which row gives the correct description of both a collagen molecule and a collagen fibre?
| collagen molecule collagen fibre
a a and b polypeptide chains molecules of collagen
forming a double helix, held arranged randomly to each other,
together by disulfide bonds linked by hydrogen bonds
b | apolypeptide chain, with repeating three molecules of collagen,
amino acids, forming an a-helix forming a triple helix, held
together by hydrogen bonds
cc a polypeptide chain, with three « helical collagen
three repeating amino acids, molecules, forming a triple helix,
forming a helix held together by ionic bonds
d three helical polypeptide chains, molecules of collagen lying
forming a triple helix, held parallel and cross-linked to each
together by hydrogen bonds other

13 the diagrams show the structures of two amino acids, each of which has two amine (—nh2)
groups.
1 2 4 5
gid-pgooi) gud er-<go0h)
i’ 1"
3
ez ch,
f°) cnh.) |
fe 6
07 “itt,)
a peptide bond is formed between the two amino acids.
which groups could form the peptide bond?
a iand4 b 1and5 c 2and6 d 3and5

14 an enzyme was added to a small excess of its substrate. all variables were kept constant.
a student was asked to sketch a graph to show how the concentration of the enzyme-substrate
complex changes over time.

which graph shows this correctly?
a b
concentration | / \ concentration j
0 0
0 time 0 time
cc d
concentration concentration |
0 0
0 time 0 time

15 the table contains results recorded by a student from an investigation into the effect of
temperature on an enzyme-catalysed reaction. all other variables were standardised.
10 3
20 7
30 16
40 33
50 32
60 14
what is the correct conclusion?
a 40°c was the optimum temperature.
b_ the data for 50°c was anomalous.
c_ the optimum temperature was between 30°c and 50°c.
d_ the optimum temperature was between 40°c and 50°c.

16 what is the correct range of measurements for the width of the cell surface membrane?
a 0.5-1.0nm b 5-10nm c 50-100nm d 0.5-1um

17 the cells in the roots of beetroot plants contain a red pigment.
when pieces of root tissue are soaked in cold water, some of the red pigment leaks out of the
cells into the water.
an experiment was carried out to investigate the effect of temperature on the loss of red pigment
from the root cells. it was found that the higher the temperature of the water, the higher the rate
of loss of red pigment from the root cells.
which of these statements could explain this trend?

1 enzymes in the cells denature as the temperature increases, so the pigment can no
longer be used for reactions inside the cells and diffuses out.

2 as the temperature increases, the tertiary structure of protein molecules in the cell
surface membrane changes, increasing the permeability of the membrane.

3 phospholipid molecules gain kinetic energy as temperature rises, increasing the
fluidity of the phospholipid bilayer and allowing pigment molecules to diffuse out
more easily.

a 1and2 b 2and3 c 2only d 3only

18 the cell surface membrane structure is described as a ‘fluid mosaic’.
which statement describes the ‘mosaic’ part of the cell surface membrane?
a the different patterns that are obtained by the moving phospholipid molecules
b_ the random distribution of cholesterol molecules within the phospholipid bilayer
c_ the regular pattern produced by the phospholipid heads and membrane proteins
d_ the scattering of the different proteins within the phospholipid bilayer

19 the diagram shows two pathways, x and y, through which molecules can diffuse across a cell
surface membrane.
x y
which row correctly shows possible pathways for lipids, water and glucose?
[tes [water [tose |
a x only x and y y only
b x only y only y only
cc x and y x only x and y
d x and y x and y x only

20 some stem cells divide and give rise to phagocytes.
where in the human body do these stem cells divide?
1 blood
2 bone marrow
3 lymph nodes
a 1,2and3 b 1and3only c 2only d = 3only

21 what is the correct sequence of stages in the mitotic cell cycle?
a g1—>g2- mitosis > s > cytokinesis
b g1>g2-—s > mitosis > cytokinesis
c g1>s-— g2 - mitosis > cytokinesis
d s—>g1-~nmitosis > g2 > cytokinesis

22 the enzyme telomerase repairs telomeres. it stops the telomeres from getting shorter each time
a chromosome is replicated.
telomerase is not normally active in human body cells, but in some diseases telomerase can be
activated.
in which disease is the enzyme telomerase activated?
a cancer
b_ hiv/aids
c_ malaria
d_ myasthenia gravis

23 the statements describe events during the mitotic cell cycle.
1 chromosomes migrate to opposite poles of the spindle.
2 chromosomes arrange themselves at the equator of the spindle.
3 chromosomes condense and the nuclear membrane disappears.
4  centromeres divide.
what is the correct order of three of these events in the mitotic cell cycle?
a 25354 b 35254 c 35452 d 452-1

24 which statement about nitrogenous bases is correct?
a_ adenine is a pyrimidine with a double ring structure.
b_ cytosine is a purine with a double ring structure.
c_ guanine is a purine with a single ring structure.
d_ uracil is a pyrimidine with a single ring structure.

25 rifampicin is an antibiotic used to treat tuberculosis.
it works by inhibiting rna polymerase in bacteria.
which of these processes will be directly inhibited by this antibiotic?
1 atp synthesis
2 transcription
3 translation
a 1and2 b iand3 c 2only d 3only

26 meselson and stahl investigated dna in bacteria. they grew bacteria in a medium with only
heavy nitrogen, ‘°n, until all of the bacterial dna contained only heavy nitrogen.
these bacteria were then moved from the heavy nitrogen medium and cultured in a medium with
only light nitrogen, ‘4n.
some bacteria were collected from each of the next three generations and their dna was
analysed.
hybrid dna contains both heavy and light nitrogen.
which row shows the correct dna of the first and third generations?
| dna of first generation dna of third generation
a all hybrid half hybrid, half light
b all hybrid one quarter hybrid,
three quarters light
cc half hybrid, half heavy half hybrid, one quarter
heavy, one quarter light
d half hybrid, half light one quarter hybrid,
three quarters light

27 the diagram shows the stages in the production of part of a polypeptide.
dna nucleotide sequence
template strand tacgacaatcgc
mrna sequence augcuguuagcg
amino acid sequence met leu leu ala
which feature of the triplet code is illustrated by the information given?
a anamino acid can be coded for by more than one triplet.
b_ the triplet code is non-overlapping and is only read in one direction.
c_ the triplet code is universal for the dna of all organisms.
d_ there are some triplets that code for ‘start’ and ‘stop’.

28 which combination of features is characteristic of a phloem sieve tube element as it unloads into
a sink?
[ee
a higher than sink absent
b higher than sink present
cc lower than sink absent
d lower than sink present

29 which statements correctly describe transport pathways in dicotyledonous plants?
1 inthe symplast pathway, water may move through intercellular spaces.
2 the symplast pathway may be blocked by the tonoplast.
3 in the apoplast pathway, water does not move through plasmodesmata.
4 the apoplast pathway may be blocked by the casparian strip.
a iand2 b 1and4 c 2and3 d 3and4

30 the diagrams show transverse sections of parts of a plant.
leaf stem
1
err 6 :
sj do ay) 3
js
: 6 es
which labelled structures transport mineral ions?
pop te 8 a
a v x v x key
b v x x jv /=yes
cc x v v x x=no
d x v x v

31 which feature of transport in plants is correct for both xylem and phloem?
a itis passive.
b_ it occurs by mass flow.
c_ it occurs from source to sink.
d_ it occurs only in one direction.

32 what is the main function of a companion cell in phloem tissue?
a providing cytoplasmic contact with the sieve tube element for loading
b providing structural support for the sieve tube element
c providing the nucleus for cell division in the phloem
d providing the source of assimilates for storage

33 the contraction of the heart is coordinated through electrical impulses passing through the
cardiac muscle.
what is the correct order of part of the sequence of these impulses?
a right and left atria — atrioventricular node — purkyne tissue > ventricular walls
bright and left atria > purkyne tissue — ventricular walls — atrioventricular node
c_ right and left atria + sinoatrial node > atrioventricular node > ventricular walls
d _ sinoatrial node — right and left atria > purkyne tissue — atrioventricular node

34 as blood flows from an artery to a vein, the thickness of the walls of the vessels changes.
which bar chart shows these changes correctly?
a b
thickness thickness
of wall of wall
art a oc ov vn art aocoeov vn
cc d
thickness thickness
of wall of wall
art a oc ov vn art aocoeov vn
key
art = artery
a = arteriole (small artery)
c = capillary
v= _venule (small vein)
vn = vein

35 the graph shows the oxygen dissociation curves of haemoglobin from two species of mammal,
s and t.
ss
percentage
saturation of
haemoglobin
with oxygen i
%
partial pressure
of oxygen/kpa
which statements could explain the difference in the oxygen dissociation curves of species s and
species t?
1 species t has a lower haemoglobin concentration in its red blood cells than
species s.
2 the haemoglobin in species t has a lower affinity for oxygen than the haemoglobin
in species s.
3 species t lives at higher altitudes than species s.
a 1,2and3 b tand2only c 2only d 3only

36 which tissues may be found in bronchioles?
a cartilage, ciliated epithelium, glandular tissue
b ciliated epithelium, elastic fibres, smooth muscle
c elastic fibres, cartilage, smooth muscle
d_ smooth muscle, glandular tissue, cartilage

37 which of these statements could describe the effect of carbon monoxide in cigarette smoke?
1 it binds irreversibly to haemoglobin.
2 it causes mucus to accumulate in the bronchioles.
3 it results in more carbon dioxide being transported in the blood.
4 it temporarily increases the heart rate.
a 1and2 b= 1 only c 2and3 d 3and4

38 the global mortality figures for some diseases in 2002 are shown in the table.
cause of millions of percentage of
death deaths all deaths
hiv/aids 2.8 44
tb 1.6 2.7
malaria ie} 2:2
measles 0.6 lal
how many millions of people died from viral diseases listed in the table in 2002?
a 22 b 34 cc 3.8 d 44

39 which of the statements could describe both b-lymphocytes and t-lymphocytes?
1 they contain specific protein receptors in their cell surface membranes.
2 they differentiate into plasma cells.
3 they divide by mitosis.
a 1and3 b= 1 only c 2and3 d 2only

40 two people, g and h, were each given an injection to protect them against a particular pathogen.
one person was injected with antibodies. the other person was injected with a vaccine.
the graph shows the concentrations of the antibody against this pathogen in the blood of the two
people, g and h, over a period of 20 days following the injection.
25 ins
20 g fe “#
antibody 15 fi "shy
concentration a
/arbitrary units 109 /
5
0
0 5 10 15 20
{ time/days
time of injection
which row correctly describes the type of immunity shown by g and h?
a artificial active immunity artificial passive immunity
b | artificial passive immunity artificial active immunity
cc natural active immunity natural passive immunity
d natural passive immunity artificial active immunity

Solve 9700_m17_qp_12