biology

1 astudent was given a photomicrograph of a cell and told the magnification of the image.
the student was asked to calculate the actual size of the cell.
which row in the table explains how to do this?

measure the convert to um by rearrange the
image in multiplying by formula to

4 m
a cm 1.0 x 10 7

b cm 1.0 x 108 ixm
4 |
cc mm 1.0 x 10 a
m

d mm 1.0 x 10* ixm

2. the electron micrograph shows part of a eukaryotic cell.
which cell structure is a site of protein synthesis?
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3 some stains can be used to identify cell structures in living cells.
a dilute solution of one stain causes the whole cell to appear blue.
the blue colour rapidly disappears in most cell structures. those cell structures that release
energy stay blue.
which type of cell structure is likely to stay blue?
a_ endoplasmic reticulum
b_ golgi body
c_ lysosome
d_ mitochondrion

4 amolecule of carbon dioxide is in the centre of a mitochondrion.
assuming there are no other cell structures in its path, how many phospholipid layers will the
carbon dioxide molecule have to pass through in order to leave the cell?
a 2 b 3 cc 6 d 8

5 which row identifies the type of ribosome found in each of the different structures?
[acon srs [mene | mie
a 70s 70s 80s 70s
b 70s 80s 70s 70s
cc 80s 70s 80s 80s
d 80s 80s 70s 80s

6 the colour of a positive benedict's test is due to the formation of copper oxide. the mass of
copper oxide is proportional to the mass of reducing sugar present.
samples of fruit juice were tested for the presence of reducing sugars and non-reducing sugars
using the benedict's test.
the table shows the mass of copper oxide after boiling with benedict's solution and after acid
hydrolysis and boiling with benedict’s solution.
which sample contained the most non-reducing sugar?
mass of copper oxide/mg
after boiling with after acid hydrolysis and
benedict’s solution boiling with benedict’s solution

a 20 20

b 30 45

cc 50 55

d 65 15

7 which polysaccharides contain 1, 4 and 1, 6 glycosidic bonds?
1 amylopectin
2 amylose
3 cellulose
4 glycogen
a iand3 b 1and4 c 2and3 d 4only

8 the diagram shows a small part of a polypeptide.
ts hs
h o ch
| h | |
ch n cc ch
n cc ch n cc
h ff ~— oh |
o oe ie)
its
ch,
what would the products be if the part shown was completely hydrolysed?
h o h fe) h o
| jf | j | j
a a a a
| \ ‘ | \
h oh oh ch oh
gos
gh gr ch, ch,
ite
ch,
h h fe) h h o h h o
\ | jz \ | g \ | g
b i —_—- oo
/ | \ / \ / | \
h h h h h h ch h
gh ch, ch, “oh,
ie
ch,
h oo h o h o
\ 4 \ vy ‘ y
c _— | ow oe
, | \ 7 \ / | \
h h oh h oh h ch oh
gn —chs ch, “6h,
i
ch,
h h fe) h h fe) h h fe)
\ | g \ | g \ | g
d ih ad =_/
f | \ / ‘ yf |
h h oh h oh h ch oh
gh—ch, cf, ch,
id
ch,

9 the enzyme trypsin hydrolyses proteins to amino acids. trypsin does not function when the ph is
very low as its 3d shape would be changed.
what explains this change in 3d shape?
a hydrogen ions attach themselves to negatively charged r groups.
b_ hydrogen ions disrupt disulfide bonds.
c_ hydrogen ions increase hydrogen bonding between amino acids.
d_ hydrogen ions reduce the affinity of hydrophilic r groups for water.

10 the flow chart shows some of the steps in the formation of collagen.
three polypeptide chains
[ together by x bonds
triple helix
a together by intermolecular bonds
¥
z
which row correctly identifies x, y and z?
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a disulfide fibres fibrils
b hydrogen fibrils fibres
cc hydrogen microfibrils fibres
d | peptide and hydrogen fibres microfibrils

11 which molecules contain at least two double bonds?
1 saturated fatty acid
2 collagen
3 haemoglobin
a 1,2and3 b 1tand2only c jdand3only d = 2and3only

12 two experiments, x and y, were carried out using an enzyme from humans.
experiment x was carried out at a constant temperature of 37°c. during experiment y, the
temperature was increased from 37°c to 80°c. all other factors were kept the same.
which graph shows the results?

a b
xx x
product product
concentration y concentration
y
042 3 4 5 012 3 4 5
time/ minutes time/minutes
cc d
x
¥
product x product
concentration concentration
¥
012 3 4 5 012 3 4 5
time/minutes time/minutes

13 what affects the rate of an enzyme-catalysed reaction when in the presence of a
non-competitive inhibitor?
1 enzyme concentration
2 inhibitor concentration
3. substrate concentration
a 1,2and3 b 1and2only c t1and3only d = 2and3only

14 what describes the fluid-mosaic model of membrane structure?
a_ cholesterol makes the membrane more fluid.
b_ fluids can cross the membrane by diffusion or osmosis.
c_ proteins act as receptors for cell signalling.
d_ proteins and phospholipids move and change places.

15 blocks of agar are stained with a ph indicator and used to investigate the diffusion of an acid
solution.
which block would completely change colour the fastest?
a 1mm x imm x 1mm
b 1mm x 0.25mm x 0.25mm
c 1mm ~x 0.5mm x 0.6mm
d 2mm «x 0.5mm x 0.6mm

16 the diagram shows the water potential of three adjacent plant cells, p, q and r.
p
-198kpa = q
) cane)
which shows the net movement of water between cells p, q and r?
a p>+qandp>randr>q
b p>qandp>r
cc q>pandq>randrp
d q>pandrp

17 which row correctly describes parts of chromosome structure present during mitosis?
p[eentomere | etomata [tomers
region of a single dna region of dna with
chromosome polynucleotide with many cytosine and
with no dna histone proteins guanine bases
region of non-coding dna double-stranded region of dna with
holding two dna molecule with many short repeated
chromatids together histone proteins sequences of bases
c region of dna with no dna molecule coiled region of dna with no
histone proteins that allows | round histone proteins | proteins that protects
separation of chromatids to form a chain of the end of a chromatid
during anaphase nucleosomes
region that attaches one of two identical region of non-coding
to spindle microtubules dna molecules that dna holding the
and divides was replicated ends of the
during prophase during interphase chromatids together

18 the diagram shows the relative time taken for each stage in the cell cycle.
which row identifies the correct sequence of the stages in the cell cycle?
[eres | _tehase | mitosis

a x ¥ z
b x z ¥
cc ¥ z xx
d z x n4

19 scientists have made a nucleic acid, hna, that has a sugar with the same number of carbon
atoms as glucose instead of deoxyribose. although genetic information can be stored by hna,
naturally occurring dna polymerase cannot replicate hna.

which statements could explain why naturally occurring dna polymerase cannot replicate hna?
1 dna polymerase cannot form bonds between the sugars of two hna nucleotides.
2 dna polymerase cannot form hydrogen bonds between two hna nucleotides.
3 hna nucleotides do not fit into the active site of dna polymerase.
4 the shape of an hna nucleotide is slightly larger than that of a dna nucleotide.

a 1,2,3and4 b t1and4only c 2and3o0nly d 3and4only

20 which statements about the nucleotide containing uracil are correct?
1 uracil is a pyrimidine.
2 the carbohydrate is always ribose.
3. base pairing occurs with 3 hydrogen bonds.
a 1,2and3 b 1and2only c 1and3only d = 2and3only

21 dna replication involves several stages.
1 each strand of dna double helix acts as a template for the opposite strand.
2 the enzyme dna polymerase links bases together.
3 hydrogen bonds between bases a and t and between c and g are broken.
which statements about dna replication are correct?
a 1,2and3 b 1and2only c 1and3only d = 3only

22 the sequence of bases in mrna for the first eight amino acids in the b-polypeptide of adult
haemoglobin is:
gug-—cac-—cug-—acu-—ccu-—gag-—gag-aag.
in haemoglobin c, which is a cause of haemolytic anaemia, the sequence is:
gug-—cac-—cug-—acu—ccu-aag-—gag-aag.
the coding for seven of the amino acids is listed.
amino acid | dna triplet
glu ctc
his gtg
leu gag
lys ile
pro gga
thr tga
phe aag
which change occurs to the amino acid sequence of adult haemoglobin to make haemoglobin c?
a histidine is changed to leucine.
b_ proline is changed to threonine.
c_ glutamic acid is changed to lysine.
d leucine is changed to phenylalanine.

23 some antibiotics kill prokaryotes by binding to rna polymerase.
what effect will this have on protein synthesis?
a_ codons on mrna will be unable to hydrogen bond to complementary anticodons on trna.
b_ condensation reactions joining rna nucleotides will not take place to form mrna.
c dnawill not unwind and unzip to allow for base pairing with rna nucleotides.
d_ free rna nucleotides will not base pair to exposed bases on the dna template strand.

24 the diagrams show transverse sections through parts of plants.
which of the labelled regions contains cells which are dead?
cc
. d
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b

25 the diagram shows the distribution of tissues in part of a transverse section through a plant
organ.
a
which row correctly identifies tissues 1, 2 and 3?
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a cortex endodermis phloem
b cortex epidermis xylem
cc endodermis epidermis pith
d pith endodermis phloem

26 the circumference of a tree stem was measured continually for 48 hours.
the results are shown on the chart recording.
circumference
of tree stem f
1200 2400 1200 2400 1200
time of day
what explains the changes in circumference recorded during the 48 hours?
a_ adhesion forces decrease during the night.
b_ cohesive tension forces increase during the day.
c_ mass flow of sucrose increases during the night.
d_ root pressure decreases during the day.

27 which description of movement in phloem is correct?

a_ adding sucrose to a sieve tube element increases its water potential so that water enters and
increases the hydrostatic pressure.

b- ata sink, such as a storage organ, sucrose is removed from a sieve tube element and
polymerised into starch.

c at a source, such as a photosynthesising leaf, sucrose enters a sieve tube element by
facilitated diffusion.

d at a source, sucrose is loaded into a companion cell using a protein that carries both
hydrogen ions and sucrose molecules.

28 which statements about blood vessels are correct?
1 collagen fibres in the walls of arteries and veins prevent overstretching.
2 elastic fibres in large arteries allow stretching during ventricular systole.
3 smooth muscle in arteries controls the distribution of blood to different parts of the
body.
4 veins have valves because their walls are thin.
a 1,2,3and4
b= 1, 2 and 3 only
c 2and4only
d 3and4 only

29 the photomicrograph shows three white blood cells labelled x, y and z.
>
x
7 fs) re
. ¥
which row correctly identifies these cells?
[ix iy az
a lymphocyte neutrophil monocyte
b lymphocyte monocyte neutrophil
cc monocyte lymphocyte neutrophil
d neutrophil lymphocyte monocyte

30 the enzyme carbonic anhydrase catalyses the reaction:
co, + h20 - hco; + h*
which statements describe the role of the enzyme carbonic anhydrase?
1 to speed up the decrease in ph of blood in the presence of carbon dioxide
2 __ to facilitate the bohr effect in haemoglobin
3. to speed up the reaction between carbon dioxide and water
a 1,2and3 b1only c 2only d = 3only

31 the graph shows the oxygen dissociation curves of adult haemoglobin at two partial pressures of
carbon dioxide w and x.
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(0) 0 a a a 7 (a oy
0 1 2 3 4 5 6 vé 8 9 10 11 12
partial pressure of oxygen/kpa
which pair of statements are correct?
1 curve w shows the oxygen dissociation curve at a higher concentration of carbon
dioxide than curve x.
2 curve x shows the oxygen dissociation curve at a higher concentration of carbon
dioxide than curve w.
3 at a partial pressure of oxygen of 7.0kpa the haemoglobin from curve w has a
higher affinity for oxygen than haemoglobin from curve x.
4 ata partial pressure of oxygen of 7.0kpa the haemoglobin from curve x has a
higher affinity for oxygen than haemoglobin from curve w.
a 1and3 b iand4 c 2and3 d 2and4

32 a person has two blood tests one month apart. the number of each type of cell in a fixed sample
size is counted.
type of cell first test after one month
red blood cells normal higher
lymphocytes normal higher
what could this suggest about the person based on the results after one month?
body temperature | moved to higher atp synthesis
higher altitude in cells is higher
a no no yes
b no yes no
[e yes no no
d yes yes yes

33 a student was asked to describe the differences between four microscope slides of sections
taken from different parts of the gas exchange system.
slide 1 not present: cartilage, glands
present: few goblet cells, ciliated epithelial cells, smooth muscle
slide 2 present: incomplete cartilage rings, glands, goblet cells, ciliated epithelial cells, smooth
muscle
slide 3 not present: cartilage, glands, goblet cells, smooth muscle
present: squamous epithelial cells
slide 4 present: plates of cartilage, glands, goblet cells, ciliated epithelial cells, smooth muscle
which is the correct identification of the parts of the gas exchange system?
[side [side [ste [side
a alveolus bronchiole bronchus trachea
b bronchiole bronchus alveolus trachea
cc bronchiole trachea alveolus bronchus
d bronchus trachea bronchiole alveolus

34 cigarette smoke contains carbon monoxide, nicotine and tar.
which row correctly describes how these substances affect the body?
[[ctonmonoate [neater
a stimulates stimulates the nervous leads to obstructive
nerve endings system to reduce the lung disease
diameter of the arteries
b forms increases the risk blocks goblet cells
carbaminohaemoglobin of blood clots
cc causes increased combines with increases the risk
blood pressure haemoglobin of blood clots
d combines with stimulates carcinogenic
haemoglobin nerve endings

35 chronic obstructive pulmonary disease (copd) includes chronic bronchitis and emphysema.
in what order do these events occur as emphysema develops?
1 macrophages move into alveolar air spaces.
2 tar paralyses cilia.
3 macrophages secrete elastase.
4 bacteria accumulate in alveoli.
a 2545153
b 254531
c 4515352
d 452531

36 if someone smokes cigarettes, what will be the immediate result of this action on the red blood
cells?
a carbon monoxide will combine with the globin in haemoglobin.
b carbon monoxide replaces carbon dioxide in carbaminohaemoglobin.
c_ less oxyhaemoglobin will form.
d more haemoglobinic acid will be formed.

37 what is correct for tuberculosis (tb)?
airborne
“ey ay
rash

38 some common antibiotics are listed. the action of each antibiotic is described.

1 rifampicin — inhibits rna polymerase
2 — streptomycin — inhibits 70s ribosomes
3 neomycin — inhibits dna synthesis
4 ampicillin — inhibits peptidoglycan synthesis

which of these antibiotics will affect the activities of bacterial cells only?

a 1,2,3and4

b= 1,2 and 3 only

c 2and4only

d 4only

39 which method of gaining immunity can be described as natural active immunity?
a feeding on colostrum
b _ inhaling the chicken pox virus
c injection with antibodies
d_ through the placenta

40 which statements correctly explain why smallpox has been eradicated, but not malaria or
cholera?
1 cholera vaccines provide only short-term immunity.
2 plasmodium antigens change during the life cycle.
3 smallpox antigens remain stable.
4 vaccines only work against viruses.
a 1,2and3 b 1,2and4 c 1,3and4 d 2,3and4

Solve 9700_s20_qp_13