biology

1 the diagram shows a stage micrometer, with divisions 0.10mm apart, viewed through an
eyepiece containing a graticule.
sea gabes asada
the area of the field of view of the microscope can be calculated using this formula.
area = nr?
a student calculated the area of the field of view of the microscope using the information provided
and a value for 2 of 3.142.
which answer has been rounded correctly to an appropriate number of significant figures?
a 0.04909 mm?
b 5x 107mm?
c 4.909 x 10* um?
d 4.91 x 10* um?

2 where are cisternae found in a cell?
1 endoplasmic reticulum
2 golgi body
3 mitochondria
a iand2 b 1and3 c 1only d 2and3

3 which row matches the functions to the cell structures?
[| vaaioie | nuceotus | ribosomes | osomes _ |
a stores water, manufactures protein involved in cell
sugar and messenger rna synthesis recognition
pigment
b | exports proteins manufactures lipid synthesis involved in cell
ribosomal rna recognition
cc stores water, manufactures protein contains
sugar and ribosomal rna synthesis enzymes
pigment
d | exports proteins manufactures lipid synthesis contains
messenger rna enzymes

4 which structures are found in prokaryotes and eukaryotes?
a_ cell membrane and nucleus
b_ cell membrane and ribosomes
c nucleus and mitochondria
d_ mitochondria and ribosomes

5 which molecules are present in all viruses?
1 thymine
2 adenine
3. cytosine
a 1,2and3 b 1tand2only c ‘1and3only d 2and3only

6 ihe table shows the observations recorded trom tests for biological molecules on four samples,
a, b, c and d.
which conclusion is correct?
benedict's biuret iodine .
: : conclusion
solution reagent solution

a blue blue blue-black contains starch only

b blue purple orange contains reducing sugar only

cc green blue orange contains reducing sugar and protein

d red blue blue-black contains starch and protein

6 which molecule is a disaccnaride and a reducing sugar?
a fructose
b_ glucose
c_ maltose
d sucrose

9 the diagram shows bonding in part of a polysaccharide.
ch,oh
oh
“ \. oh
bu)
ch,oh ch,oh ch, ch,oh
oy oy oy oy
“\.oh ° oh o oh oo oh %
oh oh oh oh
which type of glycosidic bond is shown at position x?
a a-1,4 b_ a-1,6 c b-1,4 d £-1,6

10 which statements about triglycerides and phospholipids are correct?
1 fatty acids in a triglyceride may be saturated or unsaturated but in a phospholipid
they are always saturated.
2 triglycerides and phospholipids both have a hydrophobic region.
3. triglycerides are non-polar molecules and phospholipids are polar molecules.
a iand2 b 1 only c 2and3 d = 3only

11. silk moth caterpillars have been genetically modified to produce a mixture of their own silk and
the much stronger spider silk of the golden orb web spider.
the spider silk polypeptide chain has many repeated sequences of two amino acids, glycine and
alanine, arranged in a crystalline structure.
what correctly describes the structure of spider silk?
a primary protein structure with regions of a-helices
b_ secondary protein structure with regions of b-pleated sheets
c tertiary protein structure with regions of a-helices
d_ quaternary protein structure with regions of b-pleated sheets

12 which property of the tertiary structure of a globular protein enables it to catalyse a metabolic
reaction?
a it has hydrophobic amino acid r groups on the outside.
b it will be denatured by high temperatures.
c_ the r groups of some amino acids form bonds with a substrate.
d_ the three-dimensional shape depends on hydrogen bonding.

13 astudent investigated the effect of substrate concentration on the activity of an enzyme.
the graph shows the results of this investigation.
x
activity of
enzyme
substrate concentration
an increase in which factors could lead to a change in the activity of the enzyme at point x on the
graph?
1 ph
2 _ substrate concentration
3 temperature
a 1,2and3 b 1and2only c t1and3only d = 2and3only

14 the michaelis-menten constant, km, is the substrate concentration at which an enzyme works at

half its maximum rate.

what is correct when the k,, value is low?

a_ the enzyme has a low affinity for the substrate and the quicker the reaction will proceed to
its maximum rate.

b_ the enzyme has a low affinity for the substrate and the slower the reaction will proceed to its
maximum rate.

c_ the enzyme has a high affinity for the substrate and the quicker the reaction will proceed to
its maximum rate.

d_ the enzyme has a high affinity for the substrate and the slower the reaction will proceed to
its maximum rate.

15 which functions are performed by glycoproteins on the surface of a cell surface membrane?
1 to act as enzymes catalysing reactions in the membrane
2 to have a specific site wnere chemicals can bind
3. to secrete specific chemicals used for cell signalling
a 1,2and3 b 2and3only c 2only d = 3only

16 the diagram represents a process by which molecules move out of a cell through a cell surface
membrane.
[e) @)
a 00°
5 2° 020
[oene) (2)
6 vs 0° oo
[e) oo
which process does this represent?
a_ exocytosis
b_ diffusion
c facilitated diffusion
d_ osmosis

17 the photomicrograph shows the appearance of onion epidermal cells after they have been
soaked in solution x for one hour.
ye 0) str od
fall 5h)” ew eae a eed eo
fs fe ay } ¥
dey) 4 17 ale
oie teele y pa wa
te ey [ry
oe as | 1 fica | ey
pe g heme’ |
toes po
ke i 3 [ if
ieee fe i
{ kg
ss an an |
ij \ any) \ 13
y ei ane bn | i
what fills the space labelled y?
a. air
b_ cytoplasm
c solution x
d_ water

18 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

19 which processes that occur in the cell cycle are represented in the diagram?
4
3
mass of nuclear
dna in a cell 2
/arbitrary units
1
0 ;
time
a dna replication and nuclear division only
b dna replication, nuclear division and cytokinesis
c_ mitosis and cytokinesis
d_ mitosis only

20 a gene codes for the production of a protein, p53, that binds to damaged dna during interphase
and prevents its replication. a carcinogen in cigarette smoke mutates the gene coding for the p53
protein, preventing production of the protein.

which statement explains why this mutation may cause cancer?

a_ cells with no p53 are able to undergo mitosis.

b_ cells with no p53 replicate their damaged dna.

c_ the carcinogen in cigarette smoke increases the rate of cell division.
d the mutated p53 causes uncontrolled cell division.

21° stained onion cells undergoing mitosis were observed using a microscope.
which row is correct for mitosis in plant cells?
a centrioles chromosomes pair two telomeres are two nuclear
visible up at the equator visible on each membranes form
chromatid
b centromeres chromosomes align chromosomes centrioles
present at the equator replicate to disappear
form chromatids
cc each chromosome centromeres attach | chromatids separate chromosomes
is visible as two to spindle fibres and migrate decondense
chromatids to opposite poles
d | spindle fibres formed | centromeres attach chromatids are spindle fibres
by centrioles to spindle fibres pulled apart form new nuclear
by centrioles membranes

22 how many statements about semi-conservative replication of dna in a eukaryotic cell are
correct?
1 the process takes place in the cytoplasm.
2  anadenine nucleotide will line up against uracil on the template strand.
3 each daughter molecule will contain half of the original dna molecule.
4 if the dna molecule contained 40% guanine nucleotides, each daughter molecule
will contain 20% guanine nucleotides.
a 1 b 2 cc 3 d 4

23 a section of the polypeptide coding for the haemoglobin b-chain contains the following amino
acids.
— pro — glu — glu —
patients with sickle cell anaemia have mutated f-polypeptide chains. the section of the mutated
polypeptide contains the following amino acids.
— pro — val — glu —
the table shows the possible anticodons for val.
val caa
val cag
val cac
val cau
what is the corresponding dna triplet code for the substituted amino acid in the mutated
polypeptide?
a gtt b gac cc ctcc d cat

24 which diagram correctly represents temporary hydrogen bonding during transcription?
a b cc d
a soe a g ie t tti u

25 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 1and 4 only d 2and3 only

26 the electron micrograph shows a longitudinal section through part of a plant stem.
y is rd a oven
we - on oe atk ie
x4 rn 2 book es
4 i cr ag
mcs. ° wee 4
yy lg ek 5 se pe a we sa
a
<f on es — oe
¢ on oi tes rant
by st. weg
: <a ~ i * ps ‘
ee i
a a wy : ye bars ae @
: ea ee o-
; i gs . ae
po o> cee
ie ote ):, ee
oe f ae on ae i.
what is x?
a_ xylem vessel element
b stem cell
c_ phloem sieve tube element
d companion cell

27 sodium chloride is added to a culture solution containing freshwater single-celled plant cells.
what happens to the water potential of the culture solution when the sodium chloride is added
and what may happen to the plant cells after 5 minutes?

water potential of the :
culture solution when a plant cells
sodium chloride added uge 5 muti
a becomes less negative become plasmolysed
b becomes less negative become turgid
cc becomes more negative become plasmolysed
d becomes more negative become turgid

28 which statements correctly describe transport pathways in dicotyledonous plants?
1 in the apoplast pathway, water may move through plasmodesmata.
2 inthe symplast pathway, water may move through intercellular spaces.
3 the apoplast pathway may be blocked by the casparian strip.
a iand2 b 1and3 c 2and3 d = 3only

29 which statement about the movement of water from roots to leaves is not correct?
a a continuous column of water is partly maintained by the attraction of water molecules to
cellulose.
b_ hydrogen bonding between water molecules enables mass flow of water.
c_ hydrostatic pressure in xylem vessel elements is higher in roots than in leaves.
d_ water potential changes throughout the length of the xylem vessel elements.

30 which terms describe the method by which water is transported within xylem vessel elements?
1 cotransport
2. cohesion-tension
3 osmosis
a 1and2 b 1and3 c 2only d 3only

31 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 table shows some information about three blood vessels, p, q and r, from a mammal.
wall percentage composition of wall
diameter thick
/mm ‘ —_ muscle collagen elastic
fom tissue
25 2 22 33 40
20 4 25 40 25
4 1 35 25 30
which row identifies blood vessels p, q and r?
a artery vein artery
b artery vein capillary
cc vein artery capillary
d vein artery vein

34 ventricular septal defect (vsd) is a heart defect that people can have from birth. people with
vsd have a hole in the wall (septum) that separates the left and right ventricles.
what could happen in a person with vsd?
1 blood will leak through the hole, mostly from right to left.
2 the volume of blood circulating through the lungs will be higher than in a person
without vsd.
3 less oxygen will be delivered to the body tissues.
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

35 which statement about the structure of the heart is correct?
a_ the semilunar valves close when the pressure in the ventricles falls lower than the pressure
in the arteries.
b  amuscle called the septum separates the atria from the ventricles.
c_ there is a small patch of tissue in the right atrium that acts to delay the electrical impulse.
d_ closure of valves in the veins prevents backflow of blood into the ventricles.

36 what can be found in the wall of an alveolus in the lungs of a human?
a= a
ibres
a v v x key
b x x v v = present
cc v x x x = not present
d x v v

37 what are the functions of cilia in the gas exchange system?
1 to move mucus
2 to trap pathogens and dust
3. to increase the surface area
p| + | 2 ft 3 |
a v x x key
b v v x ¥ =a function
cc x v v x = nota function
d x x v

38 cholera and tuberculosis are infectious diseases that can spread when people have to live in
overcrowded conditions.
which strategies would help control the spread of cholera and tuberculosis?
1 covering food to prevent flies landing on it
2 providing chlorinated drinking water
3. treating severe cases with antibiotics
a 1,2and3 b 1only c 2and3only d_= 3only

39 immunity to certain pathogens develops when a person is given a vaccination.
which effects of vaccination are correct?
1. production of antibodies to protect against future infections
2 results in artificial active immunity
3. stimulation of appropriate lymphocytes
a 1,2and3 b 1tand2only c 1and3only d = 2and3only

40 astudent wrote three statements about antibodies.
1 their structure depends on peptide, hydrogen and disulfide bonds.
2 they are protein molecules with both tertiary and quaternary structure.
3 four polypeptides provide four antigen binding sites.
which statements are correct?
a 1,2and3 b 1tand2only c ‘1and3only d = 2and3only

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