biology

1 some features of cells are listed.
1 cell wall
2 cell surface membrane
3. ribosomes
which features can be found in plant cells and in prokaryotic cells?
a 1,2and3 b 1and2only c 1and3only d = 2and3only

2 which of these statements about light microscopy are correct?
1 the greater the resolution of a light microscope, the greater the detail that can be
seen.
2 the greater the magnification of a light microscope, the greater the detail that can
be seen.
3. increasing the magnification of a light microscope up to its limit of resolution allows
more detail to be seen.
4 the shorter the wavelength of light used in a light microscope, the greater the detail
that can be seen.
a 1,2,3and4
b 1,3 and 4 only
c 1 and 2 only
d 4only

3. which type of cell contains the highest proportion of cell structures bound by a single membrane?
a ciliated epithelial cell
b goblet cell
cred blood cell
d_ smooth muscle cell

4 the table shows a variety of structures which may be found in cells.
which row shows structures that could be found in the root cells of a plant?
a plasmodesmata glycagen golgi body
granules

a v v x x key
b v x v v / = present
cc x v v v x = absent
d x x jv v

5. which of these cell structures are present in plasmodium?
golgi ;
body ‘on
mitochondria

6 a student was asked to estimate the concentration of glucose in a solution using the beneaicts
test. the student was provided with a 1.0mol dm™ glucose solution and was told to make a
0.6 moldm solution by proportional dilution.

which row shows the correct volumes of both 1.0mol dm glucose solution and distilled water
needed to make the 0.6moldm™ solution?
volume of yolurieee
-3
lael distilled
glucose 3
: 3 water/cm
solution/cm
a 12 8
b 10 10
cc 8 12
d 6 14

7 the diagram shows part of a carbohydrate molecule formed by glucose.
o oooo
0 > o) lo or~+o) o . oo q
o x goo = .
o od g d
o q g o
eo q gov co ad
oo -o
coe sere, c
o oo q q
6 a o) 5
5 bs a coo oq (oooh o
o oo e oa on
o
5 g gor p2q xy
go: © co q o
ooo 3 e) rs
what is the name of the molecule?
a amylose
b_ cellulose
c_ glycogen
d - starch

8 the diagram shows the relationship between some biological molecules.
which row is correct?
a
a a-glucose carbohydrate sucrose monomer fructose
b cellulose polymer starch carbohydrate amylase
cc fructose reducing sugar b-glucose monomer amino acid
d haemoglobin protein amylose polymer cellulose

9 which diagram shows the reaction that occurs to join two of the monomers that form cellulose?
i g ‘i ¢
h c—o h h c—o h h c—o h h c—o h
va n] lx xs ca ni ea s|
ar za & a br aor a
ho c——c oh , ho] c——c’ oh ho c——c c—c oh
h,o
h,o
i ¢ ‘i ¢
h c—o c—o. oh h c—o c—o. oh
a ss a ss [4 \ fe ni
bpr a kr ato kr ua kr us
ho c——c h ho c——c h ho c——c h ho c——c h
h,o
¢ gg f
h ¢—o c—c_ oh h c—o c—c_ oh
a ao ] le x |
ek by \ y or] ik »
ho c——c’ oh h c—o h ho c——c oh h c—o h
c c
h,o
. ' f
h ¢—o_o|h | ho] c—c_h h c—o c—c_h
iy n\] ye sl [7 ss a ss
an ea ka ka ot k. a
ho c——c h h c—o oh ho c——c h h ¢——o oh
(o c

10 which molecules contain c=o bonds?
1 amino acids
2 fatty acids
3 glycerol
a 1,2and3 b 1and2only c tand3only d = 2and3only

11. which row describes a collagen molecule?
bonds stabilising . . .
| | ihe mplecule iid sucre
a disulfide high temperatures high proportion double
increase flexibility of glycine
b disulfide resistant to repeat sequences single
stretching of three amino acids
cc hydrogen high tensile repeat sequences triple
strength of three amino acids
d hydrogen insoluble high proportion alpha
in water of glycine and proline

12 astudent investigated the hydrolysis of the lipid in high-fat milk, using the enzyme lipase.
e 1cm* of enzyme solution was added to 10 cm* of high-fat milk.
e the temperature was kept constant.
e the ph of the reaction mixture was recorded at time 0 minutes and every minute for
20 minutes.
which statements could be supported by the results of the investigation?
1 less product is made as time proceeds because the substrate is decreasing.
2 the ph of the reaction mixture changes more rapidly in the first few minutes and
then changes less rapidly.
3 the product gradually causes more lipase molecules to denature.
a 1,2and3 b tand2only c tand3only d 2and3only

13 a student carried out an investigation into the effect of temperature on the rate of an
enzyme-catalysed reaction.
at each temperature, the substrate concentration was measured after 10 minutes. all the other
variables were kept constant.
which graph shows the effect of increasing temperature on the substrate concentration after
10 minutes?
a b
substrate substrate
concentration concentration
temperature /°c temperature /°c
cc d
substrate substrate
concentration concentration
temperature /°c temperature /°c

14 the graph shows how the rate of an enzyme-catalysed reaction depends on the concentration of
substrate.
0.4 -oo eo
serre 1a
peeeeeeeeeaeeeeeeeeeee ee
0.3 eere eee eee
rh eere ee eee eee eee
initial rate eee eee
of reaction 0.2--eeeee ar
imniolisst eccccre eee eee
ecap
0.1 ze
sy 2
a, tl i i a aa a i a at |
s740 |
4000s |
0.0 i a a a a a a |
0.0 10 20 3.0 40 5.0
substrate concentration /mmol dm
what is the michaelis-menten constant (k,) for this enzyme under these conditions?
a 0.19 mmoldm®
b 0.38 mmoldm®
c 1.5 mmoldm®
d 5.0 mmoldm®

15 the formula shows how the rate of diffusion across a cell surface membrane can be calculated.
surface area x difference in concentration
thickness of membrane
which row shows how the fastest rate of diffusion can be achieved?

surface area difference in thickness of

available concentration membrane
a high high high
b high high low
cc low high low
d low low high

16 the diagram shows part of the cell surface membrane of an active animal cell.
more negative water potential x
l, m
g sing cs)
$8 p38 (sd
less negative water potential y
which statements correctly describe the net movement of molecules across this membrane?
1 oxygen diffuses through molecules m from x to y.
2 carbon dioxide diffuses through molecules m from x to y.
3 water moves from y to x through molecule l.
a 1,2 and3 b 1dand2only c t1and3only d = 2and3only

1/ some epidermal cells trom a well-watered plant are placed in three solutions which nave different
water potentials.
which row correctly shows the state of the plant cells in each of the solutions?
water potential of solution
lower than cells equal to cells higher than cells

a plasmolysed turgid plasmolysed

b plasmolysed turgid turgid

cc turgid plasmolysed plasmolysed

d turgid plasmolysed turgid

18 one of the chromosomes in a nucleus has a telomere which contains many repeats of the base
sequence ttaggg.
this chromosome was extracted from four different cells and the total number of bases in the
telomere was determined.
which total number of bases was found in the cell that had undergone the most mitotic divisions?
a 5548 b 5580 c 5645 d 5700

19 the chromosome content of each daughter cell must be identical to that of the mother cell for
successful cell replacement when repairing tissues.
which stages of mitosis make sure that each daughter cell receives one chromatid from each
chromatid pair?
a prophase and metaphase
b metaphase and anaphase
c anaphase and telophase
d_ telophase and interphase

20 which of these statements about cytokinesis is always true?
1 cell structures replicate.
2 cell structures are shared between two cells.
3 nuclear envelope reforms.
a 1,2and3 b 1and3only c 2only d = 3only

21 which statement is correct about the number of telomeres present in prophase of a human body
cell?
a 46 as there is one telomere at the end of 46 chromosomes
b 92s there is one telomere at each end of 46 chromosomes
c 92 as there is one telomere at the end of 92 chromatids
d_ 184 as there is one telomere at each end of 92 chromatids

22 which statement explains why dna replication is described as semi-conservative?
a half of each original strand is conserved in each new molecule of dna.
b_ half of the base sequence of each strand is conserved in each new molecule of dna.
c only one strand of dna is used as a template during replication.
d_ the template for each new molecule of dna is one strand of the original molecule.

23 asection of a dna molecule has the coding sequence: aggcaatggc.
which statements are correct?
1. this coding sequence contains 3 pyrimidines.
2 the double-stranded dna of this section contains 26 hydrogen bonds between
complementary bases.
3 the double-stranded dna of this section has 20 sugar-phosphate bonds.
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

24 xna is a laboratory-made nucleic acid made of nucleotides in which one component has been
replaced by chemical x. the chemical x is not found in nature. the part of the molecule
responsible for coding is not changed.

which organic component of a dna or rna nucleotide has been replaced by x?
a __five-carbon sugar

b_ phosphate group

c purine base

d pyrimidine base

25 which statements about trna are correct?
1 hydrogen bonds between bases temporarily hold trna against mrna.
2 the base sequences in the trna molecules are the same as the base sequences in
the mrna that is being translated.
3 the specificity of the trna molecule for glycine and the specificity of the enzyme
that loads glycine are both necessary for correct loading.
a 1,2and3 b 1tand2only c 1and3only d 2and3only

26 what is the role of atp in a companion cell when sucrose is loaded into a sieve tube element?
a moving sucrose into the sieve tube element
b_ removing protons from the sieve tube element
c_ removing protons out of the cytoplasm of the companion cell
d taking up sucrose into the cytoplasm of the companion cell

27 a potometer was used to measure the transpiration rate of a leafy shoot.
what could be the correct units?
a cmmin bocm* min“ cc cm’g'min d- cm* min“

28 which combination of features is characteristic of a phloem sieve tube element as it is loaded
from a source?
water potential at lignification of
the phloem sieve
the cell wall
tube element

a higher than source absent
b higher than source present
cc lower than source absent
d lower than source present

29 the diagrams show transverse sections of parts of a plant.
j 3
= ye
4
2
which structures, labelled 1 to 4, transport water and sucrose?
pop pe
a v x v x key
b v x x jv / = correct
cc x v jv x x = incorrect
d x v x v

30 which statement explains why the ventricles contract after the atria?
a_ the band of fibres between the atria and the ventricles conducts the excitation wave slowly.
b_ the excitation wave has to pass through a small area of conducting fibres in the septum.
c_ the excitation wave has to travel further to reach the base of the ventricles than to spread
across the atria.
d_ the excitation wave travels slowly through the purkyne tissue to reach the base of the
septum.

31. if the left atrioventricular valve in the heart does not close completely it results in blood flowing
back into the atrium during ventricular systole.
what would be the immediate effect of this back flow?
a __ blood flowing from the heart carries less oxygen because less blood enters the lungs
b_ diastolic pressure in the left ventricle falls because less blood enters the pulmonary artery
c lower systolic pressure in the left atrium and less blood enters the pulmonary artery
d_ raised pressure in the left atrium and less blood enters the aorta

32 the graph shows two oxygen dissociation curves, one for a tissue at rest and one for the same
tissue during exercise.
100 tissue at rest
_e--7777" tissue during exercise
percentage #
saturation 50 i
with oxygen i
oi
po,/kpa
what factors have caused the difference in the position of the dissociation curve during exercise
compared with the dissociation curve for the tissue at rest?
1 increase in ph
2 decrease in ph
3. increase in haemoglobin affinity for o2
4 decrease in haemoglobin affinity for o2
a iand3 b 1and4 c 2and3 d 2and4

33 which of these statements about the formation of haemoglobinic acid are correct?
1 it can only occur with the dissociation of oxygen from haemoglobin.
2 it removes excess hydrogen ions preventing blood becoming too acidic.
3 it is linked to the action of carbonic anhydrase.
a 1,2and3 b 1tand2only c 1 only d 2and 3 only

34 which of these structures contain cartilage and cilia?
1. bronchi
2 bronchioles
3 trachea
a 1,2and3 b 1tand2only c 1and3only d_= 3only

35 what correctly describes the effect of carcinogens on lung tissue that causes a tumour to
develop?
a_ cells in damaged alveoli walls divide more rapidly to replace damaged areas.
b_ cilia are paralysed and mucus accumulates in the lungs causing dna to change.
c dnachanges, causing bronchial epithelial cells to divide by mitosis in an uncontrolled way.
d haemoglobin carries less oxygen, causing bronchial cells to divide by mitosis in an
uncontrolled way.

36 which row identifies both the type of pathogen that causes cholera and the way in which cholera
is transmitted from person to person?
| | type of pathogen method of transmission
a bacteria drinking water contaminated
with the pathogen
b bacteria inhaling water droplets
contaminated with the pathogen
cc virus drinking water contaminated
with the pathogen
d virus inhaling water droplets
contaminated with the pathogen

37 why do people with hiv/aids have a higher occurrence of malaria than people without
hiv/aids?
a_ hiv/aids and malaria are both diseases where the pathogen travels in blood.
b~ hiv/aids and malaria are both transmitted in blood.
c_ hiv/aids infects t-lymphocytes which are used by the malaria pathogen.
d_ hiv/aids suppresses the immune response to the malaria pathogen.

38 how many variable regions are there on a typical y-shaped antibody molecule?
a 2 b 3 c 4 d 6

39 where are antigens found?
[psa at?
pathogen macrophage
a v jv key
b v x ¥ = antigens found
cc x v x = antigens not found
d x x

40 when an organ is transplanted from one person to another, rejection of the non-self organ must
be avoided. at the same time, the immune system of the recipient must be maintained to prevent
death from infections.

what prevents rejection of the transplanted organ?
a_ continued activity of b-lymphocytes

b natural active immunity

c natural passive immunity

d suppression of t-lymphocyte activity

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