biology

1. the actual length of a cell structure is 8 um.

which steps are used to calculate the magnification of an electron micrograph of this cell

structure?
step 1 measure the length of the cell structure image on the micrograph in centimetres
step 2. measure the length of the cell structure image on the micrograph in millimetres
step 3 divide the image length by 1000
step 4 multiply the image length by 1000
step 5 divide by 8
step 6 multiply by 8

a steps 1,3 and6

b_ steps 1,4 and6

c_ steps 2,3 and 5

d steps 2,4 and5

2 what is the typical resolution of a microscope using daylight as a light source with a x10 eyepiece
lens and a x40 objective lens?
a 0.20nm b 200nm c 100um d 400um

3 two different types of cell, p and q, were broken up using ultrasound and their contents
analysed. both types of cell contained small circular dna. the circular dna from p all carried the
same base sequence, but those from q were of two types, with different base sequences.

what may be concluded about the identity of cell types p and q?
a heart muscle fibres root cortical cells
b lymphocytes mature red blood cells contaminated by bacteria
cc mature red blood cells phloem sieve tube element
d root cortical cells leaf mesophyll cells

4 which features shown in the diagram can be present in viruses?
4 1
rna dna
3 2
70s protein coat
ribosomes
a 1,2and3 b 1,2and4 c 1,3and4 d 2,3and4

5 after boiling a sample of milk with benedict’s solution, a yellow colour is observed.
which conclusion about the sample of milk is correct?
a reducing sugars are not present.
b_ reducing sugars are present.
c_ there is a high concentration of fructose.
d_ there is a low concentration of sucrose.

6 which of the statements about polysaccnarides can be used to describe amylose and cellulose?

1 contains 1,4 glycosidic bonds
2 contains 1,6 glycosidic bonds
3 polymer of glucose

a iand2

b 1and3

c 1only

d 2and3

7 which diagram shows the formation of a peptide bond?
a b
h h fo) h h fe) h h o (9) h h
\ | gf \ | g \ | gf \ ll /
n—c—c n—c—c n—c—c c—c—n
/ | | \ / | / | \
h,o h,o
cc d
h h h o h h fe) h h
% j | j \ | \ | /
n—c—c —c—c n—c—c c—c—n
/ | \ | \ / | \ | %
h h oh h oh h h oh h h
h,o
h,o 2

8 in enzyme-catalysed reactions, the position of the amino acids found at the active site is
important.
during the synthesis of enzymes, amino acids are brought together in the correct position to form
the active site.
which levels of protein structure must be involved in forming the active site?
level of protein structure

a v jv vf v key

b v v v x v= involved

cc x v v jv x = not involved

d x v x v

9 which features affect the tensile strength of collagen?

1 the helical structure of collagen chains
2 the small r group of the amino acids in collagen
3 the insoluble nature of collagen
4 the bonds between collagen molecules

a 1,2,3and4

b 1,2 and 4 only

cc 1and3 only

d 2,3 and 4 only

10 a fixed volume of the enzyme catalase was added to a fixed volume of hydrogen peroxide
solution. the diagram shows how the concentration of product changed over the course of the
reaction.

concentration

of product

0
0 time

what explains the shape of this graph?
a_ the active sites become saturated.
b_ the enzyme was denatured.
c_ the hydrogen peroxide inhibited the reaction.
d_ the substrate molecules were used up.

11. a fixed volume and concentration of substrate and enzyme were mixed. all other variables were
kept constant. the enzyme-catalysed reaction was left until it was complete.
which graph shows how the rate of reaction changes with time?

a b
rate of rate of
reaction reaction
0 0
0 time 0 time
cc d
rate of rate of
reaction reaction
0 0
0 time 0 time

12 the fatty acids elaidic acid and oleic acid have exactly the same structural formulae, with one
double bond in the chain. however, the shapes of the chains are different, as shown in the
diagram.

elaidic acid oleic acid
’ 2
which row shows the effect of the presence of these fatty acids on the structure and behaviour of
a cell surface membrane?
ee
a does not fit closely with other fits closely with other fatty
fatty acids so that the membrane acids so that the membrane is
is less fluid at high temperatures less fluid at low temperatures
b does not fit closely with other fits closely with other fatty
fatty acids so that the membrane acids so that the membrane is
is more fluid at low temperatures less fluid at low temperatures
cc fits closely with other fatty does not fit closely with other
acids so that the membrane is fatty acids so that the membrane
less fluid at high temperatures is more fluid at low temperatures
d fits closely with other fatty does not fit closely with other
acids so that the membrane is fatty acids so that the membrane
more fluid at low temperatures is more fluid at high temperatures

13 the diagram shows a cell surface membrane.
xx peete fo os
8 , oy oh, oy
sy ey “8, “a
w_ by srey ty eeetiag! = \nanaackarpy ve
so e'e'e, eee eee eis sieisieiere lore
ut rra) te
lg
lz
which is a correct role for a labelled molecule?
a_ wis involved in controlling membrane stability.
b_xis involved in active transport.
cy is involved in cell signalling.
d__zis involved in diffusion of ions.

14 the diagram shows a simple cell signalling pathway in which a signal molecule leads to a
response, such as a secretion.
slanal + | response
molecule |” e p

which row identifies p and q?

a activated enzyme in cytoplasm target in cell surface membrane

b lipid in cell surface membrane extracellular enzyme

cc protein in cell surface membrane activated enzyme in cytoplasm

d target in cytoplasm protein in cell surface membrane

15 three parts of a chromosome and their functions are listed.
p1 centromere f1 holds the coils of dna together
p2_ histone proteins f2 holds two chromatids together
p3 telomere f3 prevents loss of genes
which part is matched with its correct function?
a p1andf1 b p2andf1 c p2and f3 d p3andf2

16 the enzyme telomerase prevents loss of telomeres after many mitotic cell cycles.
which cells need to transcribe telomerase enzyme?
1 cancer cells
2 stem cells
3 activated memory b-lymphocytes
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

17 the diagram shows some of the stages which take place during the cell cycle.
1
number of dna
molecules in
cell doubles
4 stages 2
nuclear envelope during cell
di cell grows
isappears cycle
3
chromosomes
become visible
which two stages take place during interphase?
a iand2 b 1and3 c 2and4 d 3and4

18 which statement correctly describes the base pairing in a molecule of dna?
a_ the purine adenine forms bonds with the pyrimidine thymine.
b_ the purine adenine forms bonds with the pyrimidine uracil.
c_ the purine cytosine forms bonds with the pyrimidine guanine.
d_ the purine guanine forms bonds with the pyrimidine thymine.

19 which statements about complementary base pairing are correct?

1 it allows translation to occur.
2  purines and pyrimidines are the same size.
3 the base pairs are of equal length.
4 uracil forms two hydrogen bonds with adenine.

a 1,2,3and4

b 1,3 and 4 only

c 1and4only

d 2and3 only

20 the diagram shows the possible organisation of dna molecules after one replication.
which organisation is correct?
one strand
of ~~ |
a b cc d

21 the diagram shows part of the dna sequence of a gene and a mutated sequence of the same

gene.
normal dna sequence ..ccg gat tat tgc gag aaa tgg cat tct agg...
mutated dna sequence ..ccg gat gta ttg cga gaa atg cat tct agg...
what are possible effects of the mutated sequence?

1 the presence of mrna stop codons, uag, uaa or uga

2 achange in the sequence of amino acids

3 anon-functional protein

4 ribosomes cannot translate the mrna
a 1,2and3 b 1,3and4 c 1and4only d 2and 3 only

22 vwvnat is correct tor phioem sieve tube elements?
a companion cells provide structural support to the phloem sieve tube elements.
b_lignified walls of phloem sieve tube elements prevent transport of mineral salts by mass
flow.
c_ phloem sieve tube elements become narrower as movement of sucrose occurs.
d cl ala allow movement of water and solutes across cell walls of phloem sieve tube
elements.

23 the diagrams show transverse sections of parts of a plant.
transport tissues are labelled 1 to 6.
leaf stem root
p 3
an 4 5
/\ qyg
= o ava
@e0og abo0s8 oo d
6
ree g2
2
which combination shows the tissues that have a main function of transporting water?
| fr fe2tsi4ls fel
a| vv v x x v v_ | key
b v x x v x v¥_ | “= transporting water is a main function
cc] xx v v x v x | x =transporting water is not a main function
d| x v x v v x

24 the statements are descriptions of how water moves across the root to the xylem vessel
elements.
1 water enters cell walls.
2 water enters cytoplasm by osmosis.
3 water moves from cell to cell through plasmodesmata.
4 water moves through cell walls.
which statements describe the apoplast pathway?
a 1,2,3and4
b 1,2 and 3 only
c 1and4only
d 4only

25 four plants, a, b, c and d, were grown in the same conditions and their transpiration rates
measured.

which plant is most likely to be a xerophyte?

transpiration a

rate /mgcm-* b

cc

d

00:00 12:00 24:00

time of day/hours

26 sucrose moves from a mesophyll cell in a leaf into a phloem sieve tube element.
which changes to the water potential and the volume of liquid in the phloem sieve tube element
are correct?
| ag patent volume of liquid
ecomes
a less negative decreases
b less negative increases
cc more negative decreases
d more negative increases

27 the diagram shows a cross-section through a mammalian heart.
ww
xx

which chambers of the heart are represented by w and x?
pfoow

a left ventricle right ventricle

b right atrium left atrium

cc right atrium right ventricle

d right ventricle left ventricle

28 ata certain point in a cardiac cycle, the pressure in the right ventricle is lower than that in the
right atrium and lower than that in the pulmonary artery.
which row is correct?
atrioventricular ;
semilunar valve
valve

a closed closed

b closed open

c open closed

d open open

29 the diagram shows the pathway for the transport of carbon dioxide that occurs in red blood cells.
co,
[|
h,o0
haemoglobin
which row is correct?
a
a | carbaminohaemoglobin haemoglobinic hydrogen ions hydrogencarbonate
acid ions
carbonic anhydrase carbonic acid hydrogen ions hydrogencarbonate
ions
cc carboxyhaemoglobin carbonic carbonic acid carbon dioxide
anhydrase
| haemoglobinic acid hydrogencarbonate hydrogen ions
ions

30 the diagram shows a transverse section through an artery.
uf vl \\\ x
which statement describes the tissues present in layer x?
a collagen and smooth muscle only
b elastic fibres and collagen only
c_ elastic fibres and smooth muscle only
d elastic fibres, collagen and smooth muscle

31 the large arteries close to the heart have a thick elastic layer in their walls.
which statements about this layer are correct?
1 helps to maintain the blood pressure in arteries
2 reduces friction within the arteries
3. prevents too much pressure bursting the artery wall
a 1,2and3 b 1and3only c 1 only d 2and 3 only

32 which tissues are present in the walls of a trachea and an alveolus?
epithelium with smooth
goblet cells muscle
a trachea v v
alveolus x x key
b trachea jv v v¥ = present
alveolus x v x = absent
cc trachea v x
alveolus v v
d trachea x v
alveolus x x

33 the surface tension of the layer of liquid lining the alveoli tends to pull the walls inwards so alveoli
could collapse.
which statements could explain how this is prevented?
1 alveolar fluid is moved around by cilia.
2 elastic fibres keep the alveoli open.
3 epithelial cells secrete a chemical that reduces the cohesion in water.
a iand2 b 1and3 c 2and3 d= 3only

34 the diagram shows some of the effects of nicotine and carbon monoxide in cigarette smoke.
2
1 3
carbon
monoxide
which row is correct?
a ee
a increase in heart rate short-term effect on combines more readily with
cardiovascular system haemoglobin than oxygen
b increases diameter can cause combines irreversibly
of small arteries chronic bronchitis with haemoglobin
cc reduces the oxygen short-term effect on reduces the blood
carrying capacity of blood gas exchange system supply to hands and feet
d stimulates goblet cells highly addictive increases risk
to secrete more mucus of blood clotting

35 which row correctly identifies the causative organism of each disease?
[| totere | measies | smatpox [tubers
a variola morbillivirus vibrio mycobacterium
b variola mycobacterium vibrio morbillivirus
cc vibrio morbillivirus variola mycobacterium
d vibrio mycobacterium variola morbillivirus

36 the following advice was given to a person travelling to a country where there had been an

outbreak of an infectious disease.

e cook food well and eat it hot

e peel fruit and vegetables

e = drink only cool, boiled water

e wash hands often with soap and cool, boiled water
which infectious disease would this advice help to protect against?
a cholera
b~ malaria
c_ measles
d tuberculosis

37 what is a social factor that affects the spread of malaria?
a_anincrease in drug resistant forms of malaria
b_ climate change
c difficulty in producing a vaccine
d_ migration of people because of wars

38 which are specific immune responses?
1 phagocytosis
2 production of antibodies
3. production of memory cells
a 1 and 3 only b 1 only c 2and3 only d = 2only

39 newborn babies have natural passive immunity.
what is correct for this type of immunity?
immunity is antibodies are
temporary broken down
a v jv key
b v x ¥ = correct
cc x v x = not correct
d x x

40 the diagrams show three different types of antibody structure.
\/ v4 ai
y a s yy
igg iga igm
which row is correct?
a
a one binding site for two light chains two heavy chains
an antigen molecule
b two heavy chains four binding sites five hinge regions
for antigen molecules
cc two hinge regions four heavy chains five light chains
d two light chains four hinge regions ten binding sites
for antigen molecules

Solve 9700_s19_qp_12