biology

1. what is the diameter of a typical prokaryote, such as streptococcus?
a 75x 10'nm
b 7.5x10?nm
c 7.5x10°um
d 7.5x10'um

2  aspecimen of plant tissue is first observed under a microscope using red light with a wavelength
of 650 nm.
the same specimen is then observed under the same conditions, but using green light with a
wavelength of 510nm.
what happens to the magnification and resolution when using green light compared to red light?
magnification resolution
a decreases decreases
b increases increases
cc remains the same decreases
d remains the same increases

3 which structures are present in a vibrio cholerae cell?
circular dna
a
ribosomes

4 the removal of a plant cell wall by enzyme digestion leaves an intact membrane-bound structure
called a protoplast.
which statement explains why protoplasts are easily damaged?
a_ mitochondria stop producing atp to maintain membrane integrity.
b_ net movement of water is no longer limited by turgor.
c_ secretory vesicles are unable to fuse with the cell surface membrane.
d_ the shape of the cell structures is changed by the loss of cell shape.

5. which statements are correct for a green plant?
1 atp is produced by mitochondria.
2 atp is produced by chloroplasts.
3 atp forms part of the dna.
a 1,2and3 b 1and2only c 1and3only d = 2and3only

6 which processes occur in eukaryotes and prokaryotes?
1 hydrolysis
2 mitosis
3. transcription
4 translation
a 1,2and3 b 1,2and4 c 1,3and4 d 2,3and4

7  asample of a solution was tested for reducing sugar and the result was negative.
another sample of the same solution was then tested for non-reducing sugar and the result was
positive.
which step in the test for non-reducing sugar breaks the glycosidic bonds?
a addition of benedict’s reagent
b addition of sodium hydroxide
c boiling with hydrochloric acid
d heating to 80°c

8 which row correctly identifies three polysaccharides
[se [as
straight chain branching chain straight chain
a amylose amylopectin cellulose
b amylose glycogen amylopectin
cc glycogen amylose amylopectin
d glycogen amylose cellulose

9 which row describes a triglyceride?
io
a v jv key
b jv x ¥ = correct
cc x v x = not correct
d x x

10 which diagram shows where a peptide bond would be formed?
a b
h r o h r fe) h r o (e) r h
\ | g \ | gf \ | ff \ | /
n—c—c n—c—c n—c—c c—c—n
/ | | \ / | / | \
hoh h oh hh o hh h
cc d
h r r o h r oo 4 4
\ | | jf \ | gf a
n—c—c n—c—c n—c—c n
/ | \ | \ / | |
h =h oh h oh hoh i
ie
o% “oh

11 which statements about collagen molecules are correct?
1 both types of secondary structure occur within the molecules.
2 large numbers of hydrogen bonds stabilise the molecules.
3 repeated amino acid sequences determine the tertiary structure.
a 1,2and3 b 1and2only c 1and3only d = 2and3only

12 the protein glutenin gives bread dough its elasticity. the diagram represents a polypeptide of

glutenin.
tightly tightly
coiled coiled
region region

loose spiral

what describes the structure of glutenin?

a quaternary structure because there are both globular and fibrous regions

b_ quaternary structure because there are both spiral and tightly coiled regions

c_ secondary structure because the loose spiral is an a-helix

d tertiary structure because the different regions form a 3d shape

13 which diagram correctly snows hydrogen bonding between water molecules?
the symbol 6 indicates the partial charge on an atom in the water molecule.
a b c d
o he oe ral
oy nye to nor oa nye vo noe
be le be i
ay ny a ao nod ay ny & oo no*

14 aspirin inhibits an enzyme by reacting with an amino acid that forms an essential part of the
3d structure of the enzyme. part of the aspirin molecule binds firmly with the amino acid.
what describes this inhibition?
1 competitive inhibition
2 non-competitive inhibition
3 reversible inhibition
a i1and3 b 1 only c 2and3 d = 2only

15 the table snows the michaelis-menten constant, km, for three enzymes.

c 1.5107
p 3.0 x 10“
f 5.0 x 10°

which interpretation of the information is correct?

a enzyme c has a vmax which is half that of enzyme p.

b- enzyme c will reach vmax in the shortest time interval.

c_ enzyme f has the greatest affinity for its substrate.

d_ enzyme p has a vmax of 6.0 x 10° mmoldm?.

16 the diagram is a drawing from an electron micrograph of a typical animal cell.
2o
s ye.
sh a din
zie om bf ie,
oo ib : 0
©
,
~ ad
y , ae bere
gs ad {8
x
how many layers of phospholipids will a molecule of oxygen cross to travel directly from x,
outside the cell, to y, the matrix of the mitochondrion?
a 3 b 4 cc 5 d 6

17 how could water molecules cross the cell surface membrane of animal cells?
1 carrier proteins
2 channel proteins
3. cholesterol molecules
a 1and2 b 1and3 c 2and3 d = 2only

18 the diagram shows a xylem vessel in a root and four adjacent parenchyma cells.
as water moves up the xylem vessel, it is replaced by water from cell d. water in cell d is
replaced by water in cell c, resulting in a flow of water from cell a to the xylem.
which cell has the least negative water potential?
xylem
cooo®

19 agar cubes can be used to demonstrate the effect of changing surface area to volume ratio on
diffusion.
three different agar cubes made using a dilute acid were placed into an indicator solution that
diffused into the cubes. when the indicator came into contact with the acid it changed colour.
the cubes were 1cm°, 2cm? and 3cm* and were left in the indicator solution for 10 minutes. all
other variables were kept the same. the results were recorded as diagrams.
the results for the 2cm® cube are shown.
. cube changed colour
not to original colour to a depth of 0.5cm
scale
which diagrams represent the results for the 1cm* and the 3cm* cubes?
not to
scale
cube changed colour cube changed colour
a completely to a depth of 0.5cm
tom?
3cm*
cube changed colour cube changed colour
b completely to a depth of 1cm
1com>
3cm*
cube changed colour cube changed colour
c to a depth of 0.25cm to a depth of 0.5cm
tom?
3cm?
cube changed colour cube changed colour
d to a depth of 0.25cm to a depth of 14cm
1com3
3cm>

20 the photomicrograph shows cells in different stages of mitosis.
p
- ~~ a
 # f eee bo
pt @ 2, 2% e@
‘ £ *2
pee.
pe se te
fd 7 : a ss 2
> *eee fe!
e. ’ a a
ss r
which statements are correct?
1 cell t shows metaphase.
2 dna replication occurs in cell r.
3 the amount of dna in cell p is the same as in cell t.
4 the correct order for the stages is s>r>t>p>q.
a 1,2and3 b 1,2and4 c 1,3 and4 d 2,3 and4

21 which changes in a group of mammalian cells, dividing by mitosis, would be necessary for the
formation of a tumour?
1 mitosis is no longer inhibited by cell to cell contact.
2 cells acquire the ability to migrate and set up new colonies.
3 cells become able to divide indefinitely.
a 1and2 b 1and3 c  1only d 2and3

22 which row shows some of the events during a mitotic cycle in the correct time sequence?
| time
a
a centromere of nucleoli become nuclear envelope spindle
each chromosome visible breaks into small microtubules
splits vesicles produced
b nuclear envelope spindle centromere of nucleoli become
breaks into small microtubules each chromosome visible
vesicles produced splits
cc nucleoli become nuclear envelope spindle centromere of
visible breaks into small microtubules each chromosome
vesicles produced splits
d spindle centromere of nucleoli become nuclear envelope
microtubules each chromosome visible breaks into small
produced splits vesicles
a

23 what is the maximum number of hydrogen bonds in a length of dna containing 700 base pairs?
a 350 b 700 cc 1400 d 2100

24 what is the common component of the three molecules rna, dna, and atp?
a_ adenosine
b hydrogen bonds
c_ phosphate
d_ ribose

25 photomicrographs of a dicotyledonous plant root, stem and leaf are shown.
4
c= ___- ray ey ie vs aee yao

26 which features apply to phloem sieve tube elements and to xylem vessel elements?
1 nocytoplasm
2 no end walls
3 no nucleus
a 1,2and3 b 1and3only c 2only d = 3only

27 which statement correctly describes an event in the process of mass flow in phloem sieve tube
elements?
a any part of a plant where sucrose is loaded into a sieve tube element is called a sink.
b loading sucrose into a sieve tube element increases the water potential inside it.
c_ mass flow in the phloem is a passive process occurring at the same rate as diffusion.
d sucrose moves down a hydrostatic pressure gradient in the phloem from source to sink.

28 the diagram shows a potato tuber at different stages.
1 dormant tuber (not growing)
2 sprouting roots and shoots
3. growing roots and shoots
4 making new potato tubers
1
2 —_—_ | 2
= fa ro
go qg9/
a sin p jon pl
eats . d ss — ow
2 so} 9 ee |
dal 745 |
or _
on —— i
q
8
4
which row identifies a stage where a potato tuber acts as a source and a stage where it acts as a
sink?
[sews [sink
a 1 3
b 2 4
cc 3 2
d 4 1

29 what describes the role of the atrio-ventricular node of the heart?
a_ lt causes the muscles of the ventricles to contract from the apex upwards.
b_ it delays the transmission of a wave of electrical activity from the sinoatrial node.
c_itinitiates a new wave of electrical activity in the ventricles.
d it provides a non-conducting barrier between the atria and the ventricles.

30 the diagram shows pressure changes during the cardiac cycle.
which arrow indicates ventricular systole?
20 if » wn
| | \ ) 4
i] | i \
| by i ' *.
| | |
| | ! ’ d
pressure | | 1
/kpa 10 '
i | !
al 1 ! '
; | cc i |
| \ / ! 4
pa ea a cae no
+1 ~ ee - ieotoaste
0 0.2 0.4 0.6 0.8 1.0 12 1.4
time/s

31 which process can be carried out by a mature red blood cell?
a active transport
b cell division
c phagocytosis
d protein synthesis

32 haemoglobin can bind to carbon dioxide, carbon monoxide and oxygen.
which statement about the binding sites of haemoglobin is correct?
a carbon dioxide and carbon monoxide bind to one site, oxygen binds to a different site.
b carbon dioxide and oxygen bind to one site, carbon monoxide binds to a different site.
c carbon monoxide and oxygen bind to one site, carbon dioxide binds to a different site.
d carbon monoxide, oxygen and carbon dioxide all bind to different sites.

33 which tissues are present in a bronchus?
. ciliated smooth
cartilage ae
epithelium muscle

a jv v ve key
b v v x v¥ = present
cc v x v x = absent
d x v v

34 cigarette smoke contains tar.
which statements describe the effect of tar on the respiratory system?
1 tar causes goblet cells to increase the secretion of mucus.
2 tar increases the risk of blood clots forming inside blood vessels.
3 tar may cause changes to the dna in epithelial cells.
a 1,2and3 b 1tand2only c 1and3only d = 2and3 only

35 symptoms of chronic obstructive pulmonary disease (copd) include a cough, breathlessness
and chest infections.
some of the changes in the lungs that result from smoking are listed.
1 alveoli lose elastin and collapse.
2 bacteria accumulate in the mucus.
3. cilia are inactivated.
4 goblet cells secrete more mucus.
which changes cause the cough in copd?
a 1,2,3and4 b t1and4only c 2and3o0nly d 3and4only

36 which statements about infectious diseases are correct?
1 cholera has a vaccine available and is caused by a bacterial pathogen of the vibrio
group.
2 measles has a vaccine available and is caused by a pathogen called morbillivirus.
3 smallpox was eradicated by vaccination and was caused by a bacterial pathogen
called variola.
a iand2 b 1and3 c 2and3 d = 2only

37 the antibiotic tetracycline binds to the small subunit of bacterial ribosomes, stopping protein
synthesis.
bacteria have become resistant to tetracycline due to the effect of mutations.
which effect could produce resistance to tetracycline?
a preventing tetracycline from binding to the bacterial cell wall
b preventing tetracycline from entering the bacterial cell
c preventing tetracycline from inhibiting transcription
d preventing the production of tetracycline by ribosomes

38 where are antigens found?
on the surface ‘
of macrophages in blood plasma
a v jv key
b v x v¥ = antigens found
cc x v x = antigens not found
d x x

39 the graph shows how the body reacts following exposure to an antigen for the first and second

time.

concentration first second

of antibody | ©xposure exposure

time

what is the direct cause of the increase in antibody production after the second exposure to
antigens?
a b-memory cells
b macrophages
c plasma cells
d t-memory cells

40 why has it proved difficult to develop an effective vaccine against malaria?
a mosquitoes have many stages in their life cycles.
b the human immune system does not recognise the antigens of the parasite.
c_ the parasites can only be attacked when outside the liver cells and red blood cells.
d_ vaccines are rapidly broken down by proteases in the stomach.

Solve 9700_w18_qp_12