CHAPTER 2 : CELL STRUCTURE AND CELL ORGANISATION
Year
Quantity
2003
5
2004
4
2005
5
2006
2
2007
3
2008
2
YEAR 2003
1
Figure 1(i) and Figure 1(ii) show the structures of an amoeba and a plant cell.
Figure 1(i)
Figure 1(ii)
Which structures on Figure 1(i) and Figure 1(ii) have the same function?
A W and P
B X and Q
C Y and R
D Z and S
2
Which of the following organelles contains chromosomes?
A
B
C
D
3
Nucleus
Ribosomes
Mitochondrion
Golgi body
Figure 2 shows the structure of a cell organelle
Figure 2
Which cell does not possess the organelle shown in Figure 2?
A Guard cell
B Epidermal cell
C Spongy mesophyll cell
D Palisade mesophyll cell
4
Which substance acts as the medium for chemical reactions in the cell?
A Water
B Glucose
C Fatty acid
D Amino acid
5. Figure 25 shows a cell
Figure 25
Which organelle is found in abundance in the cell shown in Figure 25?
A
B
C
D
YEAR 2004
1 The diagram shows a plant cell.
What is organelle W?
A
Nucleus
B
Ribosome
C
chloroplast
D
Mitochondrion
2
The following information refers to organelle Y.
Found in large numbers in sperm
Functions as a site to generate energy (ATP)
What is organelle Y?
A
Nucleus
B
Ribosome
C
Mitochondrion
D
Golgi body
3.
Which of the following organs is not involved in regulating the internal
environment?
A
C
B
4. What is the process?
A
B
C.
D.
Lysis
Agglutination
Phagocytosis
Neutralisation
D
YEAR 2005
1.
The following information are features of an organelle in a cell.

Spherical or oblong shaped

Smooth outer membrane and folded inner membrane
Which of the following organelles has features as stated above?
A. Vacuole
B. Nucleus
C. Chloroplast
D. Mitochondria
2.
The diagram shows an aquatic organisms.
What is the process of substances moving in and out as shown by the
organism?
A. Osmosis
B. Diffusion
C. Facilitated diffusion
D. Active transport
3.
Which of the following is a connective tissue?
4.
The diagram shows the structure of a chloroplast seen under an electron
microscope.
Which of the following processes occurs in X?
A. Reduction of carbon dioxide by hydrogen
B. Dissociation of water molecule by sunlight
C. Production of glucose
D. Production of starch
5.
The diagram shows a typical animal cell.
Which of the following is true about the functions of organelles X and Y?
Function of organelle X
Function of organelle Y
A
Site of lipid synthesis
Site of protein modification
B
Site of protein modification
Site of protein synthesis
C
Site of protein synthesis
Site of protein synthesis
D
Site of glycoprotein synthesis
Site of protein synthesis
YEAR 2006
1.
The following statements are about an organelle of a cell.
- Exist freely in the cytoplasm or attached to the rough endoplamic reticulum.
- Site of the protein synthesis
What is the organelle?
A Vacuole
B Nucleus
C Ribosome
D Golgi body
2.
Diagram 1 shows the structure of a plant cell.
Which of the following is true about X ?
A
B
C
D
Semipermeable
Elastic
Fully permeable
Rigid
YEAR 2007
1
Which of the following cells forms the basic tissues in plants?
A Guard cell
B Xylem cell
C Epidermal cell
D Parenchyma cell
2. Diagram 1 shows the cell organisation in a multicelullar organism.
Cell
Tissue
R
System
Which part of the body can be represented by R?
A Ligament
B Blood
C Epithelium
D Liver
Organism
3
Diagram 7 shows a type of fresh water unicellular organism.

Which of the labeled parts A, B, C or D performs osmoregulation?
YEAR 2008
I
Diagram 1 shows an animal cell.
What is organelle P?
A
B
C
D
Nucleus
Chloroplast
Mitochondrion
Golgi body
2. Which organ consists of cells which have the highest density of rough
endoplasmic reticulum?
A
B
C
D
Stomach
Heart
Brain
Kidney
CHAPTER 2 : CELL STRUCTURE AND CELL ORGANISATION
2005
Section
B
A
C
A
2006
Section
B
2007
Section
C

(1)
A
 (1)
2008
Section
B
A
B
 (2)
 (6a)
2009
Section
A
B
 (1)
CELL , STRUCTURE AND ORGANISATION
YEAR 2006
SECTION A
1. Diagram 1 shows a plant cell as seen under electron microscope.
Chloroplast
Nucleus
Vacuole
Golgi body
(a)(i) On Diagram 1, label the structures P, Q, R and S.
[4 marks]
(ii) State the function of structure :
P:
Q:
Absorbs light energy to carry out photosynthesis
Control the cell activities / contain DNA
[2 marks]
(b) Explain the role of R to maintain cell turgidity
F : Maintains the osmotic concentration/pressure of the cell sap
P1 : If the cell is flaccid/ cell sap has high osmotic concentration/pressure,
more water enters the cell (by osmosis)
P2 : If the cell has excess water/ cell sap has low osmotic concentration /
pressure, water will move out of the cell.
[Either P1 or P2].
[2 marks]
(c) Every somatic cell which contains structure Q has a potential to form a complete
new organism.
(i) Name the technique used to produce new plants in large quantity
Tisssue culture//cloning.
[1 mark]
(ii) By using one suitable part of the plant, explain the technique in 1(c)(i)
Able to name the part of plant used
Shoot/root/lateral buds (orchids/bananas)  (1)
Able to explain the technique used to produce new organism
Treatment
Tissue (meristem)/shoot/root/lateral buds/ is washed and treated with
sterilizing agent/bleach/hydrogen peroxide (1)
Requirement for growth
Tissue/explant is cultured in nutrient medium (sterile), suitable temperature
and pH (1)
Principle of cloning
Cells divide by mitosis to form a callus (1)
Product
Callus differentiate to form root and shoot/seedling/clone (1)
[Any three]
[4 marks]
YEAR 2007
SECTION A
2 Diagram 1 shows a cross section of organ X in the human body.
(a) (i) Name -organ X.
Skin
[1 mark]
(ii) Table 1 shows the function of several organs in the human body.
Transporting oxygen.
Regulating body temperature
 (1)
Eliminating urea
 (1)
Converting excess glucose to glycogen
 (1)
As a protective layer
Table 1
Tick () the three correct functions of organ X, in the boxes provided in Table 1.
[3 mark]
(b) Erector muscle is a tissue.
State reasons why X is classified as an organ and erector muscle is classified as
a tissue.
X: .Consist of a group of different tissues such a connective tissues, muscle
tissues;
combined together to form a specific function.
Erector muscle : Consist of a group of cells (which perform a specific function) .
[2 marks]
(c) The following information shows some of the organ systems found in the human
body. Tick () the two systems which contain organ X, in the boxes provided below.
Blood circulation system
Respiratory system
 (1)
Integumentary system
 (1)
Excretory system
[2 marks]
(d) Human body temperature is maintained at 37 °C.
Explain the roles of the erector muscle, hair follicle and sweat gland in maintaining
the
body temperature on a hot day.
Erector muscle : Erector muscle relaxes, hair lie flat against the skin/fall down
Hair follicle : (Hair lie flat against the skin) less air / a thin layer of air is trapped
between the hair and the surface of the skin.
More heat is lost to the atmosphere through radiation.
Sweat gland : Secrete sweat// sweat evaporates.
Some amount of heat/ latent heat of vapourization is lost to the
surrounding
[3 marks]
YEAR 2008
SECTION A
2. Diagram 2 shows four levels of cell organisation in humans.
Rajah 2
(a) Complete Table 2 by naming Level 2 and Level 3.
Level
1
2
3
4
Name
Cells
Tissue
Organ
System
Table 2
(b) (i) The cells undergo process X to become specific cells that perform a specific
function.
Name the process X.
Differentiation
[ 1 mark]
(ii) What is the function of the structure in level 2?
Able to contract and relax.
[ 1 mark]
(iii) The structure in level 4 is one of the body systems. Name this system.
blood circulatory system
[ 1mark]
(iv) State one function of the system in 2(b)(iii).
P1: To transport nutrients/antibodies/hormone/digested food
P2 : To helps in body defence against diseases/produce antibodies/kill
pathogen
P3 : To helps in homeostatis//balance of body fluids
[Any one]
[ 1 mark]
(c) (i) Name and explain the condition which can cause a blockage in blood vessel S.
Name : Atherosclerosis/Thrombosis//Arteriosclerosis/Embolism
Explanation :
P1 : Deposition of cholesterol/fats/fibrous tissue/dead muscle cells/clumping
blood platelets
P2 : Beneath the artery wall/inside the lumen of blood vessel
P3 : causes the narrowing of lumen /blood vessel
[Max 2 marks]
[3 marks]
(ii) A person is suffering from the condition in 2(c)(i).
State three effects on the person's health.
1. Heart attack//cardiovascular disease
2. Angina.
3. Cardiac arrest
4. Breathing difficulties
5. stroke
[Any three]
[3 markah]
SECTION B
6. (a) Diagram 6.1 shows the structure of a unicellular organism which lives in a
freshwater pond.
Diagram 6.1
Explain the function of X in osmoregulation.
P1 : Contractile vacuole regulates amount of water/osmotic pressure//
P2 : Excess of water in the cell diffuses into//enters the contractile vacuole by
osmosis
P3 : contractile vacuole enlarges/increase in size (to maximum size)//
P4 : (and then) contractile vacuole contracts/burst//
P5 : releasing water to the external environment//
P6 : X is contractile vacuole
[Max 4]
[4 marks]
YEAR 2009
SECTION A
1. Diagram 1 shows the structure of a plant cell.
(a) (i) Name organelle T. Smooth endoplasmic reticulum ()
[1m]
(ii) State two functions of the Golgi apparatus.
[2m]
1. Modify protein ()
2. Pack the final product / modified protein into secretory vesicles ()
(b) (i) Name the structure in the chloroplast which is involved in the light reaction of
photosynthesis. Grana ()
[1m]
(ii) Describe briefly the function of the chloroplast in the photosynthesis.
[2m]
Capture light energy () and converts it into chemical energy ().
CHAP 3: MOVEMENT OF SUBSTANCES ACROSS THE PLASMA
MEMBRANE
Year
Quantity
2003
3
2004
2
2005
1
2006
4
2007
2
2008
3
YEAR 2003
1.
Figure 3 shows a comparison of ion concentration in pond water and in
the cell sap of Nitella sp.
Figure 3
Which process causes the ion concentration in Nitella sp. to be higher
than that in pond water?
A
B
C
D
Osmosis
Plasmolysis
Active transport
Passive transport
2.
A student soaked a duck egg in a saturated salt solution. After a few
days, he found that the egg tasted salty.
Which of the following statements explain this phenomenon?
I
II
III
IV
A
B
C
D
3.
The egg shell and membrane are permeable to salt
Salt particles diffuse into the egg
Salt particles enter the egg by active transport
Saturated salt solution is hypertonic to the egg
I and IV only
II and III only
I, II and IV only
I, II, III and IV
Figure 26 shows an experiment on the movement of molecules across a
semi-permeable membrane
Figure 26
What are solutions P, Q and R
Q
Distilled water
C
P
1 mol dm-3 sucrose
solution
1 mol dm-3 sucrose
solution
Distilled water
D
Distilled water
0.5 mol dm-3 sucrose
solution
A
B
0.5 mol dm-3 sucrose
solution
1 mol dm-3 sucrose solution
R
0.5 mol dm-3 sucrose
solution
Distilled water
0.5 mol dm-3 sucrose
solution
1 mol dm-3 sucrose
solution
YEAR 2004
1. What are the processes involved in the movement of water and mineral
ions into root hairs?
A
B
C
D
2.
Water
Osmosis
Osmosis
Facilitated diffusion
Active transport
Mineral ions
Active transport
Facilitated diffusion
Osmosis
Osmosis
The diagram shows diffusion through a partially permeable membrane.
What are X and Y?
A
B
C
D
X
Sucrose solution 20%
Distilled water
Sucrose solution 20%
Distilled water
Y
Distilled water
Distilled water
Sucrose solution 20%
Sucrose solution 20%
YEAR 2005
1.
The graph shows the changes in mass of potato strips immersed in different
concentrations of sucrose solution.
Based on the above graph, which of the following concentrations of sucrose
solution should be used so that a flaccid potato strip regains its turgidity?
A 1.5 g per 100 ml
C 3.5 g per 100 m/
B 2.5 g per 100 m/
D 4.5 g per 100 m/
YEAR 2006
1.
Which of the following onion cells were immersed in a hypotonic solution?
2. Diagram 2 shows an experiment to investigate the movement of substances
through a visking tube.
What is the process that takes place in Diagram 2?
A
B
C
D
Osmosis
Active transport
Facilitated diffusion
Passive transportation
3. Cucumber slices are immersed in 0.1% solution. After 3 hours, the slices are
found to be turgid and hard.
Which of the following statements explains this phenomenon?
A
B
C
in
D
The cucumber cell wall prevents it from phenomenon
The cell sap is hypotonic towards the sucrose shrinking
The high concentration of the cell sap in the vacuole causes water to diffuse
The cucumber cell wall allows the sucrose molecules to diffuse into the cell
4. A plant cell is immersed in distilled water.
Which of the following is true about the movement of water molecules in the early
stage?
A The rate of water molecules exiting the cell is higher than entering the cell
B The rate of water molecules entering the cell is higher than exiting the
cell
C No water molecules are entering or exiting the cell
D The rate of water molecules entering and exiting the cell is the same
YEAR 2007
1.
Diagram 2 shows a plant cell which has been put into a particular solution.
Which is experienced by the cell?
A
Plasmolysis
B
Haemolysis
C Deplasmolysis
D Crenation
2. Diagram 3 is a graph showing the result of an experiment to determine the
concentration of the cell sap of potatoes.
At which point A, B, C or D, is the concentration of the cell sap of the potatoes?
YEAR 2008
1. A cell is immersed in distilled water for 20 minutes. It is then taken out and
immersed in 30% sucrose solution. Table I shows the observed condition of the cell.
If the cell is put back into the distilled water for 20 minutes, which condition of
the cell would be expected?
2
Diagram 2 shows the movement of molecule X across the plasma membrane
through process Y.
What is process X?
A. Osmosis
B. Simple diffusion
C. Active transport
D. Facilitated diffusion
3.
Diagram 3 shows the initial level of 10% sucrose solution in a capillary tube
before an
experiment.
Which graph shows how the level of sucrose solution in the capillary tube
changes during the experiment?
CHAPTER 3 : MOVEMENT OF SUBSTANCES ACROSS THE PLASMA
MEMBRANE
2003
Section
A
B
C

(1a
,b)
2004
Section
A
B
C
2005
Section
A
B
C
2006
Section
A
B
2007
Section
A
B



(2)
(7a,b)
(2)
2008
Section
A
B

(6 b,c)
YEAR 2003
Section B
1(a)
Figure 8 shows the beginning and the end of an experiment to illustrate a
physical process.
Distilled
water
Potassium
Mannganate
(VII) crystal
(i) Give a brief explanation of the process shown in Figure 8.
The process shown is known as simple diffusion.  (1)
At the beginning of the experiment, the concentration of potassium manganate
(VII) is higher at the bottom of the beaker.  (1) as compared with the solution
on the upper part of the beaker.
The potassium and manganate ions move from a region of higher
concentration to a region of lower concentration .  (1)according to the
concentration gradient until a dynamic equilibrium is achieved.
As a result, the ions are equally distributed throughout the whole system . 
(1)and turn the solution purple.
[4 marks]
(ii) Figure 9 shows three types of food.
Figure 9
Choose any two types of food shown in Figure 9. For each food explain one
method by which it can be preserved for a long period of time.
 Fresh Milk
Milk is preserved by pasteurisation.  (1) In this process, milk is heated to 63º
C for 30 minutes or 72º C for 15 seconds and then rapidly cooled to below 10º
C.  (1)
Pasteurisation kills microorganisms while maintaining the nutrient of the milk
and natural flavour of milk..  (1)
Pasteurisation is unable to kill all types of bacteria Therefore pasteurized milk
needs to be stored in the refrigerator.  (1)
 Fish
Fish is preserved with salt.  (1) The hypertonic solution causes fish tissues to
be dehydrated.  (1) Microorganisms cannot live without water.  (1)
 Mangoes
Mangoes are preserved using sugar, salt or vinegar.  (1) Mangoes are
immersed in vinegar or in solutions with high concentrations of sugar or salt.
 (1) Microorganisms cannot reproduce in an acidic medium or in a medium
that is high in osmotic concentration.  (1)
[6 marks]
(b)
Figure 10 shows a plant cell immersed in different concentrations of sucrose
solution
Figure 10
Explain what happens to the cell in each of the different concentrations of
sucrose solution as shown in Figure 10.
[10 marks]
When the cell is immersed into the 5% sucrose solution, the shape and
structure of the cell remains the same. (1) 5% sucrose solution is isotonic to
the cell sap. (1) Water diffuses into and out of the cell at equal rate. 
(1)Therefore, there is no net movement of water across the plasma membrane
of the cell.  (1) (no net gain or net loss). The cell retain its normal shape.
When the cell is immersed into the 30% sucrose solution, the cell becomes
flaccid,  (1) the vacuoles lose water and become smaller.  (1)The cytoplasm
shrinks and the plasma membrane pulls away from the cell wall.  (1). 20%
sucrose solution is hypertonic to the cell sap of the cell. Water diffuses out of
the vacuole by osmosis.  (1) (There is a net outflow of water from the
vacuoles by osmosis). The cell is plasmolysed.  (1)
When the cell is transferred into 0.1% sucrose solution, the cell revert to its
normal shape and structure.  (1) When placed in this solution, water diffuses
into the cell by osmosis.  (1) The vacuoles swell and the cells become turgid
without being damaged.  (1)
YEAR 2004
Section A
2. Figure 2 shows a fluid mosaic model of plasma membrane.
Hydrophilic
head
Hydrophilic
tail
Protein
carrier
(a)
Figure 2
Label any two structures J, K, L or M in figure 2 using the following terms:
Protein carrier
Protein pore
Cholesterol
(b)
Protein pore
Hydrophilic head
Hydrophobic tail
1 mark]
Molecules can pass through structure L in Figure 2 by facilitated diffusion.
(i) State one characteristic of the molecule that can pass through structure L.
Small, water soluble
[1 mark]
(ii) Explain how molecules pass through structure L.
(c)
The small molecules and ions move through the pore by simple
diffusion.
They move from regions of higher concentration to a region of lower
concentration through L.
[3 marks]
State one characteristic of the plasma membrane based on the model in
Figure 2.
Semi-permeable/selectively permeable
[1 mark]
(d)
Using the mechanism of movement of a substance across the plasma
membrane through osmosis :
(i)
Explain why food is preserved using concentrated sugar solution.
The concentrated sugar solution make the surrounding solution hypertonic,
that is more concentrated than the contents of the food.  (1)
The hypertonic solution causes the water to leave the food by osmosis.  (1)
The dehydratedcondition of food prevent the growth of bacteria and fungi
which can spoil the food.  (1)
[3
marks]
(ii)
Sketch a diagram to show the movement of substance that you have
described in (d)(i).
CYTOPLASM
EXTRACELLULAR FLUID
[3 marks]
YEAR 2005
No single question
YEAR 2006
Section B
7(a)
Plasma membrane encircles the protoplasm of a cell. As a whole plasma
membrane exhibits fluidity as if it is a layer oil in a beaker of water.
What is meant by plasma membrane exhibits fluidity?
Plasma membrane exhibits fluidity
 Very soft
 Extremely thin
 Consist of two layers of lipid (phospholipids)
 Various types of protein molecules are inserted within the two layers
of lipids
 Form a membrane that is not static but very free moving/dynamic
 Strong structure//not easily broken
[4 mark]
(b)(i) An experiment is carried out using substance R outside a cell.
The aim of the experiment is to study the effect of different concentrations of
substance R on the rate of its movement across the plasma membrane into
the cell.
Graph 7.1 shows the result of the experiment.






(ii)
Based on the graph 7.1, state an example of substance R and explain how
substance R moves across the plasma membrane
Examples of substance R are
i) Fatty acid/glycerol/Vitamin A/D/E/K
ii) Dissolved gases such as oxygen and carbon dioxide.  (1)
As the concentration of substance R increases, the rate of its movement
across the membrane increases.  (1)
Substance R moves across the plasma membrane by simple diffusion.
 (1)
Substance R dissolved in the plasma membrane and crosses it. .  (1)
The movement of substance R follows the concentration gradient. .  (1)
Substance R is soluble in lipids//plasma membrane is permeable to
substance R//molecules are very small. .  (1)
[6 mark]
The experiment is repeated by replacing substance R with substance S.
Graph 7.2 shows the result obtained
Based on graph 7.1 and 7.2, compare and explain the movement of substance R and
substance S across the plasma membrane.
Able to state the comparison and explain the characteristic of the movement of
substances R and S across the plasma membrane.
(1) F : Both substances R and S move down according to the concentration
gradient that is from a region of higher concentration to a region of
lower concentration..
P : The straight line in Graph 7.1 and the beginning of Graph 7.2 till the
concentration of 10 units shows positive gradient.
(2) F : In Graph 7.2, the graph flattens after the concentration of 10 units.
P : Movement of substrate S requires protein carrier.
(3) F : In Graph 7.1; the graph continues as a straight line.
P: Movement of substance R does not require a protein carrier
(4) F : The size of substance R is small.
P : Able to cross through the plasma membrane
(5) F : The size of substance S is big.
P: Needs the help of protein carrier.
(6) Substance R moved by simple diffusion
Substance S moved by facilitated diffusion
Note :
Every corresponding F and P- 2 marks
If F only -1 mark
(2 X 5=10 marks)
[10 mark]
YEAR 2007
SECTION A
2 Diagram 2.1 and Diagram 2.2 show two different types of movement of substances
across the plasma membrane.
(a) In Diagram 2. 1, label the following structures:
– Phospholipid bilayer, with letter J
- Carrier protein, with letter K
[2 marks]
K
J
(b) State two characteristics of the phospholipid bilayer.
1.The hydrophilic head of the phospholipid molecule is attracted to
water/dissolve in water  (1)
2. The hydrophobic tails of the phospholipid molecule is attracted to
fats/dissolve in fats.  (1)
.[2 marks]
(c) Name the process of the movement of substances across the plasma membrane
as shown in Diagram 2.1 and Diagram 2.2.
Process in diagram 2.1
 Facilitated diffusion (1)
[1 mark]
Process in Diagram 2.2

Active transport (1)
[1 marks]
(d) (i) Glucose molecules are transported across the plasma membrane into the cell
through
the process shown in Diagram 2.1. Explain why.
F : The size of glucose molecules are too big (to move through the
phospholipid bilayer) // insoluble in lipid.  (1)
P : Cannot move through the phospholipid bilayer (by simple diffusion,
therefore it must move through facilitated diffusion)  (1)
[2 marks]
(ii) If the substances in Diagram 2.2 are calcium ions, describe how they are
transported into the cell.
P1 : Movement of calcium ions are against the concentration gradient (energy
is needed)  (1)
P2 : Energy is supplied by ATP molecules (produced from cellular respiration)
 (1)
P3 : Protein carrier uses energy to bind calcium ions ( ATP)  (1)
P4 : Energy from ATP changes the shape of the carrier protein.  (1)
P5 : Calcium ions move across the plasma membrane into the cell//Calcium
ions are released into the cell.  (1)
[4 marks]
YEAR 2008
SECTION B
6 (b) Explain the similarities and differences between facilitated diffusion and active
transport in the movement of molecules across the cell membrane.
Facilitated Diffusion
Active transport
The movement of substances follows the
The movement of substances
concentration gradient//Substances
against the concentration
move from a region of higher
gradient// Substances move from a
concentration to a region of lower
region of lower concentration to a
concentration
region of higher concentration
Cellular energy is not required//No ATP is
Cellular energy is required//ATP is
used
used
The process continues until a dynamic
The process results in the
equilibrium is reached
accumulation of or elimination of
substances from the cell
Living membrane is not essential
Living membrane is essential
Substances can move through pore
Substances can move only through
protein or carrier protein
carrier proteins
[8 mark]
(c) Diagram 6.2 and Diagram 6.3 show two ways of preserving fish and vegetable.
Diagram 6.2
Diagram 6.3
Explain how the preservatives are effective in the preservation of each of the food.
Able to explain how the preservative are effective in the preservation of fish
P1 : Fish is covered by the salt solution which is hypertonic to
body/cell/tissues fluid of fish// (1)
P2 : more water diffuses out from the fish tissues into the salt solution by
osmosis// (1)
P3 : fish becomes dehydrated// (1)
P4 : prevents bacterial growth in fish tissues//kills bacteria (1)
P5 : bacterial cells are also plasmolysed//crenated (1)
P6 : preventing the decay of fish//fish an last longer  (1)
Max 4
Able to explain how the preservatives are effective in the preservation of
vegetable
P1 : Vegetables are immersed in vinegar which is acidic/has low pH// (1)
P2 : Venegar diffuses into vegetable tissues// (1)
P3 : Vegetable tissues become acidic/has low pH// (1)
P4 : (Low pH) prevents bacterial growth (in the tissues)//  (1)
P5 : Preventing decay of vegetables//last longer.  (1)
Max 4
[8 mark]
CHAPTER 3 :MOVEMENT OF SUBSTANCES ACROSS THE PLASMA
MEMBRANE
2005
 (1)
2006
 (1)
2007
-
2008
 (1)
YEAR 2005
ANSWER
1 Information:
The mass and freshness of plant tissues are influenced by osmosis.
Osmosis is influenced by the concentration of soluble substances inside and outside
the cells.
Situation:
A farmer has a rambutan orchard. Since the product of his orchard is abundant, he
decided to produce rambutan jam. Before the rambutan fruits are processed into jam,
the mass has to be maintained temporarily. Therefore, the farmer has to determine
the solution and the concentration of the solution that should be used.
Based on the above information and situation, design a laboratory experiment to
determine the concentration of the solution which will maintain the mass of plant
tissues.
Use a suitable plant tissue when designing your experiment.
The planning of your experiment must include the following aspects:
Problem statement : What is the concentration of sucrose solution that can
maintain the mass of plant tissue i.e potato?
Objective
: To determine the concentration of sucrose solution that
can maintain the mass of plant tissue i.e potato ?
Variables:
( a ) Manipulated : Concentration of sucrose soluton
( b ) Responding : Change in mass of potato cylinder
( c ) Fixed
: Volume of sucrose solution, same immersing time and
surrounding
temperature, type of potato
Hypothesis
: The higher the concentration of sucrose solution, the
lesser the mass of potato cylinder
Apparatus
weighing
Material
sucrose solution
Technique
: Cork borer, 50ml beaker, measuring cylinder, filter paper,
electronic scales, ruler, knife, stop watch.
: Potato, 0.5%, 5.0%,10.0%,15.0%, 20% and 25.0% of
:
To weigh the changes in mass of each potato cylinder by
using weighing electronic scale before and after
immersing in different sucrose solution.
Method/procedure
1 A piece of medium –size potato is chosen and strips of potato are made with
the cork-borer. Twelve strips of cylinder of 5cm were obtained.
2 Every potato cylinder is dried with filter paper, then weighed to obtain the
initial mass.
3 Six beakers are prepared and labelled A, B, C, D, E and F . Every beaker is
filled with 20cm3 of 0.5%, 5.0%,10.0%, 15.0%, 20.0% and 25.0% of sucrose
solution respectively.
4 Two potato cylinders are placed into each beaker
5 After being immersed for one hour, every potato cylinder is removed, dried
with filter paper, then weighed and measured to obtain the final reading.
6 The results are recorded in a table
7 Plot the graph of concentration of sucrose solution against the mass of the
cylinder.
Presentation of data
Concentration
Beaker
of sucrose
solution/%
0.5
A
5.0
B
10.0
C
15.0
D
20.0
E
25.0
F
mass of potato (g)
Initial
Final
Difference mass of
cylinder
(g)
Conclusion
Based on the plotted graph, the line which intersects the horizontal-axis (massaxis) indicates that there is no change in the mass of the potato cylinders
This proves that the cell sap of potato cylinder is isotonic to the concentration
of the sucrose solution at that particular point.
Planning Experiment :
7-9 ticks = 3 m
4 -6 ticks = 2 m
1-3 ticks = 1 m
YEAR 2006
1 A housewife made fruit pickles using unripe mango. During the preparation, she
placed the mango slices in water and later placed them in sugar solution.
When the mango slices were in the water, it was found that, the slices became turgid
and their sizes increased. But when they were placed in the sugar solution, the slices
became soft and shrunken.
Based on the above situation, plan a laboratory experiment to determine the
concentration of sucrose which is isotonic to the cell sap of the mango.
The planning of your experiment must include the following aspects:
• Problem statement
• Aim of investigation
• Hypothesis
• Variables
• List of apparatus and materials
• Technique used
• Experimental procedure or method
• Presentation of data
• Conclusion
[17 marksl
Answer
Problem statement : What is the concentration of sucrose which is isotonic to
the cell sap of mango?
Objective
: To study the concentration of sucrose which is isotonic to
the cell sap of mango
Hypothesis
: The concentration of sucrose solution which is isotonic to
the cell sap of mango is a point where there is no nett
change in mass of the mango strip.
Variables
( a ) manipulated : Concentration of sucrose solution
( b ) responding
: Change in mass of mango strips
( c ) fixed
: Volume of sucrose solution, same immersing time and
surrounding temperature, type of mango
Apparatus
: Cork puncher, petri dish, measuring cylinder, filter paper,
weighing scales, knife, ruler, stopwatch
Material
: Mangoes, sucrose solution 2%,4%,6%,8% and 10%, water.
Technique
: To weigh the changes in mass of each mango strips by
using weighing electronic scale before and after
immersing in different sucrose solution.
Method/procedure
1 Five petri dishes are labelled A,B,C,D and E.
2 Fill each petri dish with sucrose solution as follows:
Petri dish
Sucrose solution
A
20 ml of 2% sucrose solution
B
20 ml of 4% sucrose solution
C
20 ml of 6% sucrose solution
D
20 ml of 8% sucrose solution
E
20 ml of 10% sucrose solution
3 Use cork puncher to obtain five cylindrical strips of mangoes
4 Cut each strip such that the length is 40 mm respectively
5 Weigh each strip and record its initial mass
6 Put each strip into the respective petri dishes and leave it for 30 minutes
7 Take out the strips and dry the strips with filter paper
8 Weigh the strips that has been dried up
9 Record the results in a table
10 Plot the graph of concentration of sucrose solution against the mass of the
strips
Presentation of data
Petri
Initial mass of strip Final mass of
Difference in mass of strip
dish
(g)
strip (g)
(g)
A
B
C
D
E
Conclusion
The concentration of sucrose solution which is isotonic to the cell sap of
mango is a point where there is no nett change in mass of the mango strip.
Planning Experiment :
7-9 ticks = 3 m
4 -6 ticks = 2 m
1-3 ticks = 1 m
YEAR 2008
1. A semipermeable membrane in defined as a membrane that allows certain
molecules to diffuse through it but does not allow the diffusion of other molecules.
The diffusion of molecules through a semipermeable membrane depends on the
size of the molecules.Based on the above information, plan a laboratory
experiment to study the size of molecules that can diffuse through a
semipermeable membrane.The planning of your experiment must include the
following aspects:
• Problem statement
1. What size of molecule can diffuse /pass through a visking
tubing(v.t)/semi permeable membrane(spm)?
2. What substances/solutes/solutions can diffuse through a v.t /spm?
3. Can glucose and starch be detected outside the v.t /spm when tested
with benedict’s solution/iodine test?
• Objective of investigation
1. To study the size of molecules that can diffuse through a
semipermeable membrane.
• Hypothesis
1.
Small molecules/substances can diffuse through the v.t but not the
large molecules.
2.
Water/Glucose can diffuse through the v.t but not starch
3.
Glucose is tested positive but not starch in the water outside the v.t
• Variables
Manipulated : Size of molecules//(type of substance/solutes/solution// at
least a pair of different size of substances
Responding : food test(result)/ (+ve) test for glucose/ (-ve)test for starch/
change in colour / diffusion of molecules through spm/v.t
Fixed : Visking tubing / any other spm/time/temperature //
volume/concentration of substances in v.t
• List of apparatus and materials Experiment using food test
Apparatus (A)
1. beaker
2. test tube/ boiling tube
3. Bunsen burner
4. syringe/ measuring cylinder
5. stopwatch
Materials (M)
1. Benedict’s solution/ Iodine solution
2. Visking tubing
3. starch suspension/ sucrose solution
4. glucose/ water
5. thread
• Technique used
Able to state the operating responding variable correctly
1.
Carry out food test on…../glucose/starch// using benedict’s
solution/Iodine solution on the liquid outside the visking tubing in the
beaker and record the result change of colour
• Experimental procedure or method
1.
A Visking tubing is soaked in water to soften it.
2.
The Visking tubing is tied at one end of the tube tightly with a piece of
thread
3
Visking tubing is filled with 10 ml glucose solution using a syringe
4.
The other end of the tube is tied tightly with a piece of thread.
5.
The outer surface of the Visking tubing is rinsed with distilled water.
6.
The Visking tubing is immersed into a beaker filled with distilled water.
7.
After 20 minutes, a Benedict’s test is carried out on the liquid outside
the Visking tubing in the beaker.
8.
Steps 1-6 are repeated by using starch suspension.
9.
Iodine test is carried out on the liquid outside the Visking tubing in
the beaker.
10.
The results of the both test are recorded in a table.
• Presentation of data
Able to construct a table to record all data with the following aspects
1. At least 2 titles (MV and RV) and unit
2. No data is required
Refer below for sample table of result of food test
Solution inside
Solution outside Visking tube
Visking tubing
Benedict’s Test
Iodine Test
Glucose
Starch
• Conclusion
- Small molecules/substances can diffuse through the v.t but not the large
molecules.
- Water/Glucose can diffuse through the v.t but not starch
- Glucose is tested positive but not starch in the water outside the v.t

Planning experiment
7-9 ticks = 3 m
4-6 ticks = 2 m
2-3 ticks = 1 m
[17 marks]