biology

1 astudent observes a cell using a light microscope. the student then draws the cell.
which items will the student need to calculate the magnification of the drawing?
1 eyepiece graticule
2 ruler
3. hand lens
4 stage micrometer scale
a 1,2,3and4
b 1,2 and 4 only
c 1 and 3 only
d 2and 4 only

2 which equations correctly snow the relationship between magnification, image size and actual
size in microscopy?
1. magnification = pros 12s,
actual size
2 magnification = aaa sea size
image size
3 actual size = _image size |
magnification
4 actual size = hahiisset,
image size
a iand3 b 1and4 c 2and3 d 2and4

3. in which cell structures does dna transcription occur?
chloroplast
mitochondrion &p)-

4 which rows could correctly identify the nucleic acids present in two different virus particles in a
sample of air?
[en an]
1 v v key
2 v x ¥ = nucleic acid present
3 x v x = nucleic acid not present
4 x x
a iand2 b 1and3 c 2and3 d 3and4

5 tests on four samples from a mixture of biological molecules gave the results shown in the table.
boiled with boiled with excess
teat excess benedict’s solution after biuret iodine
benedict's acid hydrolysis and reagent | solution
solution neutralisation
which biological molecules were in the mixture?
a reducing sugar and protein
b_ reducing sugar, non-reducing sugar and starch
c non-reducing sugar and protein
d non-reducing sugar and starch only

6 one molecule of x is formed by a single condensation reaction releasing one molecule of water.
what is molecule x?
a adisaccharide
ba phospholipid
c a polysaccharide
d_atriglyceride

7 the table shows some information about carbohydrate polymers.
which row describes glycogen?
a4 g-1.6 shape of function of
glycosidic glycosidic fgleglie foigshig
bonds bonds
a v v branched storage key
b v x helical storage / = present
cc x jv branched structural x = not present
d x x helical structural

8 the diagrams show four phospholipid molecules.
which molecule could contribute most to the fluidity of a cell surface membrane?
a b
a i el l.,.tf™tf"ete ll.

9 which properties of phospholipids explain why single layers of phospholipids added to water
immediately form bilayers?
1 the hydrophobic fatty acid chains repel water molecules so the tails pack together.
2 the non-polar fatty acid chains are attracted to each other by hydrophobic
interactions.
3 hydrogen bonds form between the phosphate groups and water.
a 1,2and3 b 1tand2only c t1and3only d = 2and3only

10 the diagrams show three examples of different bonds.
bond 2
bond 1 o bond 3
\ | os i
nh----o==c —c—n— —ch,—s—s—ch,—
/ \ |
h
which bonds hold the tertiary structure of proteins together?
a 1,2and3 b 1dand2only c t1and3only d = 2and3only

11. which feature of collagen enables it to fulfil a structural role in skin and in tendons?
a_ adjacent collagen molecules are linked by ester bonds.
b_ collagen fibres form layers with the fibres in different directions.
c collagen molecules are formed as a triple helix of polypeptide chains.
d_ polypeptide chains of collagen are tightly folded into compact shapes.

12 the graph shows how the concentrations of four components, 1, 2, 3 and 4, of an
enzyme-catalysed reaction change with time.
1
concentration
2
3
ay
time
which component is the enzyme-substrate complex?
a 1 b 2 cc 3 d 4

13 the table shows the michaelis—menten constant, km, for three enzymes.

c 1.5 x 107
p 3.0 x 104
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 vinax of 6.0 x 10°°> mmol dm”.

14 what explains how a signal molecule produced by one cell can be detected by a target cell?
a assignal molecule can bind to any type of cell surface receptor.
b_ assignal molecule has a complementary shape to a cell surface receptor.
c_ signal molecules enter the cell by diffusion.
d_ signal molecules enter the cell by endocytosis.

15 some enzymes are produced in the cells of the pancreas. the enzymes are secreted when
required.
which process is used to transport these enzymes out of the cells of the pancreas?
a active transport
b facilitated diffusion
c_ endocytosis
d_ exocytosis

16 plant cells were submerged in a solution with a water potential less negative than that found
inside the cells.
what describes the condition of the plant cells after 20 minutes?
a burst
b _ incipient plasmolysis
c_plasmolysed
d turgid

17 what will be present in each chromosome at the end of the g2 phase of the cell cycle?
a_ two centrioles
b_ two centromeres
c_ two molecules of dna
d_ two telomeres

18 which events listed are part of the cell cycle?
1 interphase
2 metaphase
3 cytokinesis
a 1,2and3 b tand2only c t1and3only d 2and3 only

19 which features of an organism are affected by a drug that kills cells that are dividing mitotically?

1 cell repair
2 cell replacement
3 number of stem cells
4 tissue repair
5 tumour formation

a 1,2,3,4and5

b= 1,2 and 3 only

c 1,4 and 5 only

d 2,3,4 and 5 only

20 the graph shows how the distance between sister chromatids (curve p) and the distance
between chromatids and centrioles (curve q) changes during part of mitosis.
40 ,curve p
if
ee
-
distance if
/um 20 /
ra
gf
rs curve q
a blt vv www xx
time
which statements could be correct?
1 t to v represents interphase.
2  ttow represents metaphase.
3  wtox represents anaphase.
a 1and3 b 2and3 cc 1only d 2only

21 which statement helps to explain why the two sugar-phosphate chains in a dna molecule are a
constant distance apart?
a adenine and thymine are held together by the same number of hydrogen bonds as cytosine
and guanine.
b_ each nucleotide molecule is the same size.
c_ each purine base is linked to a pyrimidine base.
d___the sugar-phosphate strands of the helix are held together by sulfur bridges.

22 during dna replication, what must happen before a newly added nucleotide is bonded to the
next nucleotide in the strand?
1 complementary base pairing
2 hydrogen bond formation
3 phosphodiester bond formation
a 1,2and3 b 1tand2only c 1and3only d 2and3only

23 an antibiotic enters bacterial cells through a membrane channel protein, p.
some bacterial cells have shown resistance to this antibiotic by acquiring a mutation which
alters p. this mutation prevents the entry of the antibiotic into the cell.
which conclusions can be drawn about how resistance to this antibiotic developed in these
bacteria?
1. the mutation changed the order of the amino acids in the gene coding for p.
2 the mutation resulted in the production of p with an altered tertiary structure.
3 the antibiotic is a hydrophobic molecule and so cannot cross the phospholipid
bilayer to enter the cell.
a 1,2and3 b 1and3only c 2and3only d = 2only

24 wvnat is the correct trna anticodon coding for the amino acid proline?
aminoacid dna triplet code
on transcribed strand
alanine cgt
histidine gtg
proline ggt
a cca b ccu c ggt d ggu

25 the table shows the observations made by a student about three different cell types, p, q and r,
seen in a transverse section of a plant stem, using a light microscope.
ratio of cell wall
width to whole structures observed in cell contents
cell width
1:10 none
1:20 regular pattern of circles in some cells
1:20 granular appearance of all cells
what type of cells are p, q and r?
a companion cell phloem sieve tube element xylem vessel element
b companion cell xylem vessel element phloem sieve tube element
cc xylem vessel element companion cell phloem sieve tube element
d xylem vessel element phloem sieve tube element companion cell

26 water molecules are attracted to each other. this property is important in the upward movement
of water in xylem.
which term is used to describe the attraction of water molecules to each other?
a_ adhesion
b_ cohesion
c hydrophilic
d polar

27 the diagram shows a model to demonstrate mass flow.
i water
concentrated wy, dilute sucrose solution
sucrose solution [8 2 _|
partially permeable partially permeable
membrane membrane

in a plant, what are the structures w, x, y and z and what is the direction of flow of solution
along w?

a ww x ¥ zz from z to y

b ww x zz. ¥ from y to z

cc x ww via z from y to z

d x ww zz ¥ from z to y

28 the parts of the heart that control heart action are listed.
e — sinoatrial node (san)
e atrioventricular node (avn)
e purkyne tissue
which row is correct for atrial contraction and ventricular contraction?
| | atrial contraction ventricular contraction
a avn produces san produces
waves of excitation waves of excitation
b purkyne tissue carries avn produces
waves of excitation waves of excitation
cc san and avn produce purkyne tissue carries
waves of excitation waves of excitation
d san produces purkyne tissue carries
waves of excitation waves of excitation

29 the diagram shows part of the circulatory system in a mammal.
) 1 i2i 8 4 |
vacs nn ann
ne
ca =a) ar) |
san} direction of
eo + blood flow
direction of sog, } :
blood flow shos: a
aorta 0 7
> ol) poh
a
where is the blood pressure and the speed of flow the lowest?
lowest blood lowest speed
pressure of flow
a 1 4
b 2 3
cc 3 2
d 4 1

30 the photomicrograph shows human blood cells.
"wp —_ sw
» & “eee
> © ea)
cds) x
©0000 a’. <
what type of blood cell is x?
a_ b-lymphocyte
b monocyte
c_ phagocyte
d_ t-lymphocyte

31 the diagram shows some of the reactions of carbon dioxide when it enters the blood from cells in
a metabolically active tissue.
which reaction is catalysed by the enzyme carbonic anhydrase?
co,
plasma
a b
co, * ho — hco, — h* + hco
cc d
go; + h,o > h,co, > h* + hco,
red blood cell

32 the graph shows the oxygen dissociation curves for haemoglobin in animals that live at high
altitude and animals that live at low altitude.
100
high
altitude
percentage
saturation
of haemoglobin low
with oxygen altitude
0 :
partial pressure of oxygen/kpa
what explains the oxygen dissociation curve at high altitude?
a haemoglobin has a higher affinity for oxygen.
b haemoglobin releases oxygen more readily.
c_ the change in partial pressure of carbon dioxide causes a bohr effect.
d_ the decrease in percentage of carbon dioxide causes the curve to shift to the left.

33 the diagram shows three features found in the mammalian gas exchange system.
ciliated goblet
epithelium cells
cartilage
which structures of the gas exchange system could be represented by x in the diagram?
a small bronchiole only
bs small bronchiole and bronchus
c trachea only
d_ trachea and bronchus

34 what are short-term effects of nicotine on the cardiovascular system?
1 constriction of small arteries
2 increase in heart rate
3. increase in blood pressure
a 1,2and3 b 1dand2only c t1and3only d = 2and3only

35 some features of a disease are listed.

e it can be transmitted by animals to other animals, including humans.
e one mode of transmission is by transfusion with contaminated blood.
e the causative organism can show multiple drug resistance.
e the majority of humans who die from the disease are children.

which disease has all these features?

a cholera

b- hiv/aids

cc malaria

d tuberculosis

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 which description of multiple drug resistance in bacteria is correct?
a bacteria have dna with resistant genes for several different types of antibiotic.
b_ different species of bacteria have dna with resistant genes for one type of antibiotic.
c_ large numbers of one species of bacteria are immune to several different types of antibiotic.
d many different species of bacteria are immune to one type of antibiotic.

38 which description of a t-lymphocyte is correct?
a they are only found in blood and secrete cytokines in response to infection.
b_ they can leave the blood and accumulate at sites of inflammation.
c_ they can leave the blood and secrete cytotoxins when exposed to bacteria.
d_ they circulate in the blood and always present antigens in response to infection.

39 where are antibodies found during an immune response?
rman
of memory cells plasma
a jv v key
b v x ¥ = antibodies found
cc x v x = antibodies not found
d x x

40 monoclonal antibodies are used in the diagnosis and treatment of disease. they are produced
using a technique known as cell fusion.
which two structures are fused together in this technique?
a antigens and hybridoma cells
b_ t-lymphocytes and cancer cells
c_ cancer cells and plasma cells
d hybridoma cells and antibodies

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