PAST YEAR BIOLOGY

PSPMCompilation of Biology Past Year’s Questions SB026

11.0 BIODIVERSITY
Session 2003/2004
1. FIGURE 2 shows the reproductive structures of plant from Phylum X and Y.

Phylum X Phylum Y

FIGURE 2

(a) State the name for [2 marks]
Phylum X : Anthophyta
Phylum Y : Coniferophyta

(b) There are two classes in Phylum X. Identify the two classes. [2 marks]
Monocotyledonae
Dicotyledonae

(c) State one difference between the ovule structure, phloem and xylem tissues of

Phylum X and Phylum Y. [3 marks]

Phylum X Phylum Y

Ovule : Protected in ovary Not protected in ovary
Phloem : Have companion cells No companion cells
Xylem : Have xylem vessels No xylem vessel

(d) State the gametophyte for Phylum X. [1 mark]
embryo sac/ pollen grain

(e) How do flowers help in the survival of Phylum X ? [2 marks]
attract pollinator agent
protect the ovule in the ovary

1

PSPMCompilation of Biology Past Year’s Questions SB026

Session 2012/2013
1. Obelia sp. is a type of marine hydroid and its life cycle is shown in FIGURE 1.

Y
X

Z

FIGURE 1 [1 mark]
(a) What is meant by polymorphism?

Organisms with two or more different body form/ structure

(b) Name the structure X, Y and Z. [3 marks]
X : feeding polyp/ gastrozoids
Y : medusa
Z : planulae larva

(c) Briefly describe sexual and asexual reproduction in Obelia. [2 marks]

- For asexual reproduction, reproductive polyp/ gastrozoids produce medusa

through budding

- For sexual reproduction, the sperm from the male medusa and ovum from

female medusa combine to form zygote

(d) State the differences between reproductive and feeding polyps. [2 marks]

Reproductive polyp has medusa buds while feeding polyp has tentacles.

(e) Give TWO functions of the single opening of gastrovascular cavity in Cnidarians.
[2 marks]

Mouth/ ingestion
Anus / egestion

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2003/2004 [5 marks]
(a) Why is Marchantia sp. not widespread on land?

Session 2004/2005

(a) Describe sexual reproduction in pteridopytes and bryophytes. [10 marks]

(b) Pteridophytes are considered more advanced compared to bryophytes but are less

advanced than higher plants. Explain why. [10 marks]

Session 2005/2006

(a) Discuss the five-kingdom system as proposed by R.H. Whittaker. [10 marks]
(b) Describe the characteristics and classification of Kingdom Fungi. [10 marks]

Session 2006/2007

(a) Compare and contrast between Nematode Ascaris and Annelid Pheretima.

[11 marks]

(b) Discuss the classification of fungi into three major phyla. [9 marks]

Session 2007/2008

(a) Describe the unique characteristics of Phylum Chordata. [10 marks]

(b) Differentiate between plant from the group conifers and angiosperms.

[10 marks]

Session 2008/2009

(a) Discuss about the Whittaker five-kingdom classification system of living

organisms. [10 marks]

(b) Compare between the phylum Platyhelmintes and phylum Annelida.

[10 marks]

Session 2009/2010

(a) Explain the characteristics of arthropod that allow them to successfully conquer

various types of habitat. [12 marks]

(b) Discuss the alternation of generation in the life cycle of Marchantia. [8 marks]

Session 2010/2011

(a) List the unique characteristics of the phylum Cnidaria, and describe briefly the

life cycle of Obelia. [12 marks]

(b) Explain why bryophytes are considered to more advanced than green algae but

more primitive than ferns. [8 marks]

Session 2011/2012

(a) Name the four major groups in the plant kingdom and discuss the major

evolutionary trends across the groups. [10 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

(b) Differentiate the characteristics between Nematoda and Annelida. [10 marks]

Session 2012/2013

(a) (i) What are the unique characteristics used to identify Ginkgophyta? [4 marks]

(ii) Differentiate morphological characteristics between Coniferophyta and

Gnetophyta. [6 marks]

(b) Describe the classification of animals based on their body cavity formation and

give an example for each class. [10 marks]

Session 2013/2014

5. (a) Explain the major evolutionary relationship between groups in the plant kingdom.

[8 marks]

(b) Explain the unique characteristics of arthropods that made them as one of the most

diversified phyla. [12 marks]

Session 2014/2015

(a) Explain the unique characteristics of the Kindom Monera. [7 marks]
(b) What are the importance of protists to other living organism? [5 marks]
(c) Describe the unique characteristics of the Phylum Chordata. [8 marks]

Session 2015/2016

(a) Describe the main characteristics of the following Phyla;

(i) Chordata.
(ii) Arthropoda.

[ 1 0 marks]

Session 2016/2017

5 (a) Bacteria, Archaea and Eukarya are three different domains of living organisms.

Compare these three domains based on its structure. [8 marks]

(b) Arthropod is the most diversified and success phylum in Kingdom Animalia. Relate the

unique characteristics to the success of this phylum. [12 marks]

4

PSPMCompilation of Biology Past Year’s Questions SB026

12.0 ECOLOGY
Session 2003/2004

1

(a) State the type of food chain that constitutes the above food web. [1 mark]
Grazing food chain

(b) i. What is an autotroph? [1 mark]

Autotroph is an organism that manufacture organic substance from

non-organic substance by photosynthesis / chemosynthesis /

sunlight

ii. Name the trophic level occupied by the autotroph in the above

food web. [1 mark]

Producer (first trophic level)

(c) The formation of new tissue by autotroph does not utilize all of the absorbed
sunlight. State TWO reason for the loss of energy at this level. [2 marks]
Some of the energy is being reflected
Some are used in transpiration
Some are used for respiration (cell) / metabolism/ excretory

(d) i. State the number of trophic level for the above food web. [1 mark]
4

ii. The number of trophic levels is usually less than five. Explain. [4 marks]

The size of the organism usually bigger so more energy is

required 1

Energy is lost through transpiration/ excretion/ transpiration/

death

Only a small quantity of energy left in the 5th trophic level.

It is insufficient of energy to support more than 5/next trophic level

The higher the trophic level, the food chain become more unstable

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2004/2005

(a) How many trophic levels are involved in the energy flow? [1 mark]
4

(b) Name the process involved in biomass production in autotroph. [1 mark]
Photosynthesis

(c) What is another name for autotroph? [1 mark]
Producer

(d) Calculate the percentage of efficiency of carbon fixation in biomass by

autotroph. [1 mark]

99168/1.88 x 106 x 100% = 5.27%

(e) Give ONE example each for abiotic and biotic factor that influence energy flow.
[2 marks]

(i) Abiotic factor : Temperature
(ii) Biotic factor : Autotroph, Heterotroph

(f) Name TWO processes involved in the release of carbon dioxide into the

atmosphere. [2 marks]

Respiration

Burning/ combustion

Soil erosion

(g) Give ONE example for each of the following : [2 marks]
Detritivore : Earthworm
Decomposer : Bacteria/ Fungi

6

PSPMCompilation of Biology Past Year’s Questions SB026

Session 2007/2008

(a) Name zones X, Y, and Z. [3 marks]
X : liitoral
Y : limnetic
Z : profundal // profundal & limnetic

(b) State ONE example of primary consumer in zone Y. [1 mark]
Zooplankton

(c) (i) What happen to the photosynthesis rate in zone Y as it gets deeper?
[1 mark]

Decreases. Photosynthesis rate = respiration rate

(ii) Based on your answer in (c) (i), what is the net primary productivity (NPP)?
[1 mark]

NPP = 0

(d) What is the energy source for organisms in zone Z and where does it come from?

Energy source from organic matter / detritus / dead animal & plant /plankton.

Drift down from littoral / X and limnetic / Y zone [2

marks]

(e) Zone Z does not exist in shallow lakes. Why? [1 mark]
Sunlight reaches all the way to the bottom of lake

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2010/2011

(a) State ONE advantage of both pyramids. [1 mark]

The number of organism (especially the larger animals) can be counted

(easily) / pyramid of numbers can be constructed easily

(b) Write an example of a food chain involving each of the following groups of
organisms.

(i) S, T, U and V. [2 marks]
Trees / plants caterpillars  small birds / carnivorous bird 
Hawk / large carnivorous birds

(ii) J, K, L and M. [2 marks]
Paddy plants  rats  fleas  parasitic protozoa

(c) Give THREE disadvantages of using the above pyramids of numbers.
[3 marks]

- Changes in size of the organism during its life cycle / larval or juvenile
forms are not taken into consideration

- Problems of classifying / grouping the organism that feed at different
trophic levels

- Difficulty in counting small organisms that is very large in numbers
- A typical pyramid shape may not be produced

(d) State TWO reasons why trophic level of food chain do not exceed four or five

levels. [2 marks]

- becoming more unstable, therefore can threaten with extinction /

unstabilising ecosystem

- the need of energy increase at the trophic level

- only a small amount energy is left

- energy is insufficient

8

PSPMCompilation of Biology Past Year’s Questions SB026

Session 2011/2012
5 FIGURE 1 shows the flow of energy through a food chain in a lake ecosystem.

Light Producers A 1o A 2o
energy Consumers Consumers

Death

FIGURE 1

(a) State the process in which light energy is converted into chemical energy by
the producers.
[1 mark]
Photosynthesis

(b) Why is the percentage of light energy converted to chemical energy by the
producers are small?
[1 mark]
Most light are reflected away / not absorbed by plants/ do not fall on
plants

(c) A represents a process of energy flow from one trophic level to another trophic
level. Identify A.
[1 mark]
feeding/ ingestion

(d) Give an example of the following trophic levels in the above food chain.
[3 marks]

Producer : Phytoplankton
1o consumer : Zooplankton/ small fish
2o consumer : fish /big fish

9

PSPMCompilation of Biology Past Year’s Questions SB026

Session 2014/2015
1 FIGURE 1 shows a food web.

(a) Suggest ONE organism from FIGURE 1 that represents: [3 marks]
A producer : Carrot /Grass /Paddy
A primary consumer : Grasshopper/rat/rabbit/bird
A secondary consumer : Fox/Owl/Bird

(b) State the difference between a food web and a food chain. [2 marks]

Food chain is the pathway for the transfer of energy from one trophic level to

another while food web consists of several food chain// Food chain shows linear

feeding relationship while food web shows an interconnected feeding relationship

(c) What do the arrows in the food web indicate? [1 mark]
Direction of energy flow // consumption of the organism // eaten by

(d) State the type of energy that is channeled through the food web. [1 mark]
Chemical (energy)

(e) At each level, part of the energy is lost to the environment. State TWO ways through

which energy is lost at each level of the food web. [2 marks]

Through respiration

Through perspiration (sweat) // urination / excretion / egestion /defeacation

(f) Which population would be increased the most if the owls are eliminated? [1 mark]
Rat

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2006/2007

(a) Explain what is meant by an ecosystem. [10 marks]

(b) Explain how energy is transferred along the food chain in an ecosystem.

[10 marks]

Session 2008/2009

(a) Discuss the types of interaction between the biotic components in an

ecosystem. [10 marks]

(b) Discuss a lake ecosystem structure. [10 marks]

Session 2015/2016
(a) i) Describe the lake ecosystem in terms of their zonation and its biotic
components.
[10 marks]

(a) ii) Give an example of a food chain in a lake ecosystem and explain why a food
chain does not consist of more than 5 trophic levels.

[4 marks]

11

PSPMCompilation of Biology Past Year’s Questions SB026

13.0 POPULATION ECOLOGY
Session 2008/2009
1 FIGURE 4 shows the growth curves of two typical populations, X and Y.

FIGURE 4

(a) Based on the above graph, determine the carrying capacity of ecosystem. [1 mark]
1000 (N)

(b) Population Y shows an S-shaped curve where the environmental resistance will slow down
the rate of population growth.

(i) Write the formula for area Z which existed due to the environmental resistance.

(K-N) or [1 mark]
Carrying capacity – total no. of individual in a population

K Carrying capacity

(ii) How may the carrying capacity of the ecosystem can be increased beyond the
existing carrying capacity?
[1 mark]
Provide more food / larger area / reduce predation

(iii) Suggest one way to manage the population size of deer living in a forest to reduce its
impact on the environment.
[1 mark]
Introduce predator / hunting season

(c) Population X shows a J-shaped growth curve where growth of the population continues
exponentially by utilizing their full biotic potential.

(i) What is the term for this type of species and give an example? [2 marks]
(OUT OF SYLLABUS)

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PSPMCompilation of Biology Past Year’s Questions SB026

(ii) Suggest one environmental resistance that will acts against the exponential increase of
population X.
[1 mark]
Lack of resources/disease/competition/end of breeding season/change in climate

(iii) Extrapolate the curve of population X to show the effects of the environmental resistance

suggested in (ii) above.

#Line drawn must be under carrying capacity &must not reach 0 [1 mark]

(d) Some environmental resistance is said to be density-dependent. What is meant by the
term density-dependent AND give an example of a density-dependent factor?
[2 marks]
- The growth rate (of a population) is dependent on its density
- E.g. : Predation/disease/competition/lack of resources

Session 2012 / 2013

2 TABLE 1 shows paramecium growth when cultured separately

Days No. of P.caudatum No. of P. Aurelia
0 (per drop) (per drop)
2 4 4
4 10 10
6 30 46
8
10 48 66
12 58 70
14 62 69
16
60 71
61 71

60 71

TABLE 1

(a) Based on the data in TABLE 1, predict the result when the two species are cultured

together in a conical flask and the medium is refreshed daily. [2 marks]

The number of P. aurelia increases while P. caudatum decreases

(b) (i)Sketch a graph of your predicted result based on your answer in 2 (a). [3 marks]
Correct label for both axes:1
Shape and label of graph:2/0

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PSPMCompilation of Biology Past Year’s Questions SB026

(ii) Explain your answer.
[2 marks]

P. aurelia is more abundant (than P. caudatum).
P. aurelia uses resources more efficiently (compare to P. caudatum).

(c) What is the limiting factor in this experiment? [1 mark]
Space

(d) State the type of competition: [2 marks]

(i) Based on the data in TABLE 1.
Intraspecific

(ii) Based on the predicted graph in 2 (b)(i)
Interspecific

Session 2007/2008
(a) Explain how density dependent limiting factors affect the population size.

[12 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

14.0 VARIATION
Session 2007/2008
1 FIGURE 3 shows the modes of speciation.

(a) Identify the modes M and N. [2 marks]
M: Allopatric speciation
N: sympatric speciation

(b) Explain TWO characteristics each for M and N. [4 marks]
M: - Gene flow interrupted/ reduced due to geographical barrier

- A population form new species while geographically isolated
- Population undergo evolution change
- Reproductive isolation established

N: - Speciation take place in geographically overlapping population
- A small population becomes new species without geographic speciation
- Results from non-random mating due to sexual selection
- A reproductive barrier isolates a subset of a population without geographic
separation from the parent species.

(c) (i) State the type of isolating mechanism, which prevent the formation of hybrid zygotes.
[1 mark]

Prezygotic/ habitat/ seasonal/ behavioural/ mechanical/ genetic/ ecological

(ii) State the type of isolating mechanism in which hybrid zygotes fail to develop or sterile.
[1 mark]

Post zygotic/ hybrid inviability/ reduced hybrid fertility/ hybrid sterility/ hybrid
breakdown

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PSPMCompilation of Biology Past Year’s Questions SB026

(d) How can allopolyploidy directly cause speciation? [1 mark]
It can overcome hybrid sterility

(e) Plant species A has a diploid number of 28. Plant species B has a diploid number of 14. A

new sexually reproducing species C arises as an allopolyploid from hybridization of A and

B. What is the chromosome number of fertile hybrid C? [1 mark]

42

Session 2011/ 2012
2 FIGURE 2 shows two types of variation in human population.

FIGURE 2

(a) What is the type of variation shown by the FIGURE 2? [2 marks]
[3 marks]
Variation A:
Variation B:

(b) State THREE differences between variation A and variation B.

Variation A Variation B

(c) Give a brief definition of variation in a species. [1 mark]
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PSPMCompilation of Biology Past Year’s Questions SB026

(d) List THREE factors that can influence the variation in a species. [3 marks]

(e) What will happen to a population which lacks variation? [1 mark]

Session 2013/ 2014

1 FIGURE 1 shows graphs representing three types of natural selection. The arrows
indicate selection pressures.

FIGURE 1

(a) State the types of selection in I, II and III. [3 marks]

I : directional (selection)
II : disruptive (selection)
III : stabilising (selection)

(b) Name ONE example for each type of selection.
[3 marks]

I: industrial melanism/ Biston betularia/ black peppered moth// beak sizes of
Galapagos finches// body sizes of black bears// body size of guppy// big
horn sheep/ ram

II: variety of beak sizes and shapes of Galapagos/ Cameroon finches//
polymorphism

III: human birth weight// wing length of hawk/ eagle

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PSPMCompilation of Biology Past Year’s Questions SB026

(c) Give TWO differences between natural and artificial selections.

[2 marks]

Natural selection Artificial selection

Selection agent is environment Selection agent is human
Planned event// selected
Random event// by chance// on any wild organisms
organisms Selected varieties are defective
because of inbreeding
Selected varieties are robust/ strong/ tough// (depression)
fittest variety

(d What is the significance of selection in III?
[1 mark]

Favour the average/ intermediate phenotype/ variants// tend to eliminate
extreme phenotypes/ variants// enhance uniformity

(e) Give ONE advantage of natural selection.

[1 mark]
Advantageous/ favourable genes/ alleles can be passed/ transmitted to the
next generation// survival of the fittest// responsive to changes in
environment

Session 2015/2016

1. M and N in FIGURE 1 show two types of variation in human population.

FIGURE 1

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PSPMCompilation of Biology Past Year’s Questions SB026

(a) Name the type of mutation of variation M and N. [2 marks]
M : Continuous/ Quantitative (variation)
N : Discontinuous/ Qualitative (variation)

(b) Define variation in a species. [1 mark]

The difference in characteristics (morphology/ phenotype/ traits/ behaviour) between

individuals from the same species

(c) Give THREE factors that influence the variation in a species. [3 marks]

(Difference) in genetic (mutation/ crossing over/ random mating/…) constitution

Environmental (climates/ food supply/ culture/ soil…) conditions

The effects of interaction between the genetic and environmental

(d) State THREE differences between the variation of M and N. [3 marks]

Variation M Variation N

Individuals cannot be grouped into distincInt dividuals can be grouped into distinct

phenotypic groups phenotypic groups

Normal distribution (curve) is obtained Discrete/ distinctive distribution (curve) is

obtained

Having intermediate phenotype/ Do not have intermediate phenotype/

characteristics characteristics

Characteristics are quantitative// can be Characteristics are qualitative// cannot be

measured/ graded on a scale measured/ graded on a scale

Controlled by the additive effects of two oCr ontrolled by a single gene (which have

more genes/ polygenes two or more alleles)

Can be influenced by environmental factoCrsannot be influenced by environmental

// can be influenced by environmental andfactors// can be influenced by genetic

genetic factors factors

(e) State the consequence to a population with no variation. [1 mark]
The population will be extinct

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2006/2007 [8 marks]
[12 marks]
(a) Compare and contrast continuous and discontinuous variation.
(b) Discuss the isolation mechanism of speciation.

Session 2008/2009

(a) Discuss variation and their importance in a natural population. [10 marks]

(b) What is meant by speciation and briefly describe the various intrinsic isolating

mechanism that give rise to speciation. [10 marks]

Session 2009/ 2010 [10 marks]
[10 marks]
(a) Explain natural and artificial selection.
(b) Describe the types of natural selection.

Session 2010/ 2011 [12 marks]
[8 marks]
(a) Describe the types of natural selection.
(b) Explain the mechanism of allopatric speciation. [10 marks]
[10 marks]
Session 2012/ 2013
(a) Describe the types of natural selection.
(b) Explain the effects of genetic drift and the factors involved.

Session 2014/ 2015

(a) FIGURE 6 shows two different traits in human population.

FIGURE 6
Compare the variation types shown in FIGURE 6.

[8 marks]
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PSPMCompilation of Biology Past Year’s Questions SB026

(b) Explain the role of reproductive isolating mechanisms in preventing populations of
different species from interbreeding.
[12 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

15.0 BIOCATALYSIS
Session 2006/2007
1 FIGURE 2 shows three different enzyme reactions. A and B represent two types of

inhibitors.

(a) How do enzymes speed up the rate of reactions? [1 mark]
Lower the activation energy

(b) State the type of inhibitors A and B. [2 marks]
A : competitive inhibitor
B : non-competitive inhibitor

(c) How do inhibitors A and bind to the enzyme? [2 marks]
A : bind to active site
B : bind to allosteric site

(d) What happens to the rate of reaction with inhibitors A and B if the substrate concentration

is increased? [2 marks]

A : increase

B : no change / unchanged / remains the same / no effect

(e) Draw a curve to show the effect of increasing the temperature to enzyme activity.

[2 marks]
Peak OF CURVE : 35-45OC

Shape of curve : 1 m (bell shaped skewed to the right : not symmetrical bell shaped)

(f) State the level of protein structure that form enzyme. [1 mark]
tertiary / quaternary structure 22

PSPMCompilation of Biology Past Year’s Questions SB026

Session 2009/2010
2 FIGURE 2 shows the effect of factor X and factor Y on the rate of enzymatic reaction.

(a) (i) State the factor X and factor Y. [2 marks]
Factor X : Substrate // Enzyme concentration
Factor Y : Temperature

(ii) What is point Q? [1 mark]
Optimum temperature // maximum rate of reaction

(iii) What happens to the active site of enzyme at the point A to point B? [1 mark]
All active sites of enzymes are saturated with substrate

(iv) How do the kinetic energy of enzyme and substrate effects the reaction rate at the

point P to point Q? [3 marks]

- The kinetic energy of (enzyme and substrate) increases

- The number of collisions of (enzyme and substrate) increases

- Formation of enzyme-substrate complex increases

(v) What happens to the enzymes at point R? [1 mark]
Denatured

(b) State the level of protein structure that forms enzymes. [1 mark]
Tertiary / Quaternary structure

(c) How do enzymes speed up the rate of reactions? [1 mark]
Lower the activation energy

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2012/2013
3 (a) Draw a graph showing rates of reaction with an without the presence of an enzyme.

[3 marks]

(i) What is activation energy? [1 mark]
The minimum energy required for a chemical reaction to take place. [1 mark]

(ii) How does an enzyme influence a biochemical reaction?
By lowering the activation energy

(b) FIGURE 3 shows an enzyme action.

FIGURE 3

(i) Identify the sites labeled F and G. [2 marks]
F : active site
G : allosteric site

(ii) Structure H can bind to G site. What is H and how does it affect the rate of reaction?
[3 marks]

- Non-competitive inhibitor
- Change the structure of the enzyme // substrate no longer fit into the active site
- Reduce/lower/decrease the rate of reaction

24

PSPMCompilation of Biology Past Year’s Questions SB026

Session 2014/2015
2 FIGURE 2 shows an enzyme activity in a chemical reaction.

FIGURE 2

(a) (i) Identify T. [1 mark]
Active site

(ii) Name the monomer of T. [1 mark]
Amino acids

(iii) What is the main function of T?
[1 mark]

Attaches / binds a substrate (to form an enzyme-substrate complex) //
enzyme's catalytic centre // catalyse the conversion of substrate to product

(b) Molecule P is an organic molecule tightly bound to the enzyme. [1 mark]
(i) Identify P.

Prosthetic group

(ii) Give ONE example of P. [1 mark]
FADH2 / FMN / FADH / FAD // Haem // vitamins

(c) Why is P more stable compared to an enzyme? [1 mark]
P is not a protein and will not denature

(d) Give TWO factors which prevent the production of R and S. [2 marks]

Extreme temperature // very high temperature / very low temperature
Extreme PH / too acidic / too basic
Presence of inhibitor

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PSPMCompilation of Biology Past Year’s Questions SB026

(e) (i) State the condition during which an enzyme is saturated.
[1 mark]

When active sites are fully filled / occupied / bound with substrates.

(ii) In what way the enzyme productivity can be increased in 2 (e) (i)? [1 mark]
Add more enzymes.

Session 2016/2017

1 (a) Define enzyme.

[1 mark]

______________________________________________________________

(b) State t h r e e (3) properties of enzymes.

[3 marks]

______________________________________________________________

_____________________________________________________________

_____________________________________________________________

(c) What determines the amount of product produced in an enzymatic reaction?
[2 marks]

______________________________________________________________

_____________________________________________________________

(d) What will happen to the rate of enzyme activity when the shape of enzyme's
active site is altered? Give a reason
[2 marks]
______________________________________________________________

_____________________________________________________________

(e) Catecolase causes the browning of cut fruits like apples. An apple was bitten
in two areas; one area was exposed while another area was covered with
lime juice. Why had the exposed area turned brown?
[2 marks]

______________________________________________________________

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2007/2008

a) Describe how substrate concentration and pH affect the rate of enzyme catalyzed

reaction. [10 marks]

b) Explain the mechanism of enzyme action using ‘induced fit’ hypothesis with an aid

of a diagram. [10 marks]

Session 2008/2009

a) Describe the properties of an enzymes. [10 marks]

b) With the aid of a diagram, discuss the effect of temperature on the enzymatic

reaction

[10 marks]

Session 2010/2011

(a) Describe enzyme classification according to the International Union of

Biochemistry (IUB). [12 marks]

(b) Explain the different types of cofactor. [8 marks]

Session 2013/2014

(a) Explain the mechanism of enzyme action using ‘lock and key’ hyphotesis and

‘induced fit’ hyphotesis. [10 marks]

(b) Briefly discuss the types of cofactor with appropriate examples. [10 marks]

Session 2015/2016

(a) Describe the properties of enzyme and how pH can affect the rate of enzyme-
catalysed reaction.

[12 marks]

(b) Explain the mechanism of enzyme action based on 'lock and key' hypothesis and
'induced fit' hypothesis.

[8 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

16.0 CELLULAR RESPIRATION
Session 2007/2008
1 FIGURE 3 represents two main stages in cellular respiration.

FIGURE 3

(a) Name the reaction that occurs at step 2, 3, and 4 and the two by-products of the reaction.

(i) Reaction : Oxidative decarboxylation

[1 mark]

(ii) By-products : NADH (+ H+) and CO2

[2 marks]

(b) At which step does the substrate level phosphorylation occur, and how many ATP(s) are

produced at this step from one molecule of glucose? [2 marks]

i) Step : 5/1
ii) ATP(s) : 2/4 *ATP dependent on step

(c) State what happens to the hydrogen produced at step 6. [2 marks]
Hydrogen reduces/ bind/combine with FAD
FADH2 is formed

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PSPMCompilation of Biology Past Year’s Questions SB026

(d) Identify compound X. [1 mark]
Acetyl CoA

(e) The reduced co-enzyme produced in step 1 will enter the electron transport system.

(i) What is the reduced co-enzyme? [1 mark]
NADH

(ii) What is the reaction involved in the production of ATP when the reduced co-

enzyme in e (i) enters the electron transport system? [1 mark]

Oxidative phosphorylation

Session 2008/2009
2 FIGURE 2 shows some of the steps involved in cellular respiration in muscle tissues.

FIGURE 2

(a) Name the process which involves the above steps. [1 mark]
Glycolysis

(b) In which TWO steps are ATPs being used? Why ATP used? [3 marks]

- P/glucose Glucose- 6-phosphate

- Q/Fructose-6-phosphate Fructose-1,6-bisphosphate

- Makes the molecule more reactive//increase the energy level of

molecule//supplies energy to the molecule// acts as a phosphate

donor//phosphorylase the molecule

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PSPMCompilation of Biology Past Year’s Questions SB026

(c) Name the enzymes involved in steps P and Q. [2 marks]

Step P: hexokinase
Step Q: phosphofructokinase

(d) In which step is NADH produced? State the function of NADH. [2 marks]

Step S/glyceraldehyde-3-phosphate

(As a coenzyme that) transfers electrons (to specific carrier)/electron carrier to

the transport chain/system//as reducing agent/reduce pyruvate to

lactate/regenerate NAD+ (which is needed in glycolysis)

(e) How many molecules of NADH and pyruvate are produced from one molecule of 1,3-

biphosphoglycerate? [2 marks]

0 NADH

1 Pyruvate

Session 2010/2011

3 FIGURE 3 shows a schematic diagram of cellular respiration.

FIGURE 3

(a) Name the type of cellular respiration shown in FIGURE 3. [1 mark]
Fermentation/anaerobic respiration

(b) (i) State in what condition does the cellular respiration in 3 (a) to occur. [1 mark]
In the absence/lack of oxygen

(ii) Give ONE example of the importance of this process in industry. [1 mark]

Baking bread

Making/manufacturing of fermented food/beverages such as

tapai/dadih/cencalok/budu/tempe/yogurt/cheese/beer/wine/ alcohol/taucu

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PSPMCompilation of Biology Past Year’s Questions SB026

(c) Name the process N. [1 mark]
Glycolysis [4 marks]

(d) Name the substances J, K, L, and M. [1 mark]
Substances J : Pyruvic acid/pyruvate [1 mark]
Substances K : Ethanal/acetaldehyde
Substances L : Ethanol
Substances M : lactic acid/lactate

(e) How many ATP molecules are produced from the process in FIGURE 3.
4

(f) What is the role of NADH in the above process?
Reducing agent

Session 2011/2012
4 FIGURE 4 shows the process of cellular respiration in liver cells.

FIGURE 4 [1 mark]
(a) Define aerobic respiration.

Complete oxidation of glucose to CO2 and H2O in the presence of O2

(b) How many ATPs are produced from the substrate level phosphorylation from one molecule

of glucose in the Kreb’s cycle? [1 mark]

2

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PSPMCompilation of Biology Past Year’s Questions SB026

(c) State TWO byproducts formed when pyruvate is converted to acetyl coenzyme A.

[2 marks]
CO2
NADH/NADH + H+

(d) (i) What will happen to pyruvate in the absence of oxygen? [2 marks]
Pyruvate will be reduced by NADH
To produce lactic acid

(ii) Why is the process in (d) (i) is important? [1 mark]
ATP can still be produced

(e) Cytochromes are parts of electron transport chain.
(i) Name the class of enzymes that can be found in the electron transport chain. [1 mark]
Oxidoreductase

(ii) What will be produced when an electron is transported through the chain. [2 marks]
Water/H2O
ATP

Session 2013/2014

2 FIGURE 2 shows the Krebs cycle in cellular respiration.

FIGURE 2 [2 marks]
32
(a) Name the processes at steps Q and R.
Q : Isomerisation

PSPMCompilation of Biology Past Year’s Questions SB026

R : (Oxidative) decarboxylation

(b) How many NADH are produced from one molecule of glucose? [1 mark]
6

(c) Which step in the above figure does the substrate level of phosphorylation occur

and how many ATP are produced at this step from one molecule of glucose?

[2 marks]

Step :T

ATP : 2

(d) (i) Which step in the above figure produce FADH2 ? [1 mark]
U

(ii) What is the function of FADH2? [1 mark]

Electron donor/reducing agent// shuttle high energy electron/ electron

carrier into electron transport chain (ETC)

(e) Where does the Krebs cycle takes place? [1 mark]
Matrix of mitochondria

(f) What are the by products formed at steps Q and R? [2 marks]
Q : water molecule/ H2O
R : NADH and CO2

2. FIGURE 2 represents four steps in glycolysis.
Fructose -6-phosphate

A
B

1,3-biphosphoglycerate [1 mark]
FIGURE 2 [2 marks]

(a) State the precise location in a cell where glycolysis occur. 33
Cytoplasm/ cytosol

(b) Identify compound A and B.
A : Fructose 1,6-bisphosphate
B : Glyceraldehyde 3-phosphate/ G3p/ PGAL

PSPMCompilation of Biology Past Year’s Questions SB026

(c) Based on FIGURE 2, identify the steps in which: [2 marks]

ATP is consumed : fructose-6-phosphate to fructose-1,6-biphosphate/

bisphosphate/ A // production of compound A (through

phosphorylation)

NADH is produced : Glyceraldehyde-3-phosphate/ G3P/ PGAL/ B to 1,3-

biphosphoglycerate// production of 1,3-biphosphoglycerate

(d) State ALL the end products of glycolysis. [1 mark]
(2) NADH, (4/2) ATP and (2) Pyruvate

(e) State the total energy yielded from glycolysis of TWO glucose molecules. [2 marks]

Net ATP : 4 ATP

NADH : 4 NADH

(f) Explain briefly substrate-level phosphorylation that occurs in glycolysis. [2 marks]

(An enzyme facilitates direct) transfer of a phosphate group from a substrate to ADP

To form ATP

Session 2016/2017
2. FIGURE 2 shows a diagram of cellular respiration.

FIGURE 2 [1 mark]
34
(a) Name the process shown in FIGURE 2.
Anaerobic respiration // fermentation

PSPMCompilation of Biology Past Year’s Questions SB026

(b) (i) State the condition on how the process can occurs.
[1 mark]

In the absence of oxygen / does not required oxygen

(ii) Give o n e ( 1 ) example the used of this process in industry.
[1 mark]

- Bread making
- Manufacture of beer / wine / alcohol beverages
- Making / fermented dairy product such as yoghurt /
cheese
- Manufacture of ethanol
- Making of fermented food taucu / tapai / cencalok /

tempoyak / budu / soy sauce / tempe

(c) Name compound A, B, C and D. [4 marks]

A : carbon dioxide
B : ethanol / acetaldehyde
C : ethanol
D : lactic acid / lactate

(d) Identify the role of NADH in the above respiratory process.
[1 mark]

The hydrogen donor // reducing agent // electron carrier

(e) Write the chemical equation to summarize the respiratory process that

takes place in FIGURE 2 if it happen in: [2 marks]
(i) plant cell : C6H12O6  2C2H5OH + 2CO2
(ii) animal cell : C6H12O6  2CH3CH(OH)COOH / 2C3H6O3

Session 2003/2004

(a) With reference to a labeled diagram, describe Krebs cycle. [20 marks]

Session 2004/2005

(a) Compare between aerobic and anaerobic respirations. [8 marks]

(b) Describe the stages in the production of NAD and its role in cellular respiration.

[12 marks]

Session 2005/2006

(a) Describe how one molecule of glucose is able to produce 36 ATP via aerobic

respiration. [14 marks]

(b) Explain the production of lactic acid during anaerobic respiration. [6 marks]

Session2006/2007

(a) Explain how electrons from NADH and FADH2 flow through the electron transport chain

with the production of ATP. [12 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

(b) Compare and contrast between fermentation and aerobic respiration. [8 marks]

Session 2008/2009

(a) Explain how protein and lipid are used as alternative energy source. [8 marks]

Session 2009/2010

(a) Explain the steps in Krebs cycle that produce high energy molecules. [10 marks]

(b) Discuss the fermentation pathways under anaerobic condition that occurs in plant and

animal cells. [10 marks]

Session 2012/2013

(a) Explain the process in the final stages of cellular respiration occurring in the electron

transport chain. [12 marks]

(b) Discuss the similarities and differences between anaerobic and aerobic respiration.

[8 mark]

Session 2015/2016

(a) The normal blood glucose level is 70 - 110 mg/100 mL. Explain how this glucose
level is maintained.

[8 marks]
(b) Describe how the characteristics of the functional units of a kidney enhance its
function.

[12 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

17.0 PHOTOSYNTHESIS

Session 2003/2004

1. Photosynthesis consists of two reaction, light dependent reaction and light independent

reaction. The light independent reaction in C3 plants is different from that of C4 plants.

Complete TABLE 1 with correct statements to show the differences between the light

independent reaction in C3 and C4 plants. [10 marks]

Description C3 Plants C4 Plants

Number of CO2 fixation Once Twice

Name of CO2 fixation RuBP carboxylase/Rubisco Phosphoenolpyruvate/PEP
enzyme RuBP carboxylase

CO2 receptor Phosphoenolpyruvate
RuBP

First product of CO2 3-Phosphoglycerate/PGA Oxaloacetate
fixation Mesophyll
Mesophyll and bundle
Type of plant tissue sheath cell

Photosynthesis efficiency Less efficient More efficient

TABLE 1

Session 2004/2005

2 FIGURE 2 shows the schematic diagram of light dependent reaction of photosynthesis.

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PSPMCompilation of Biology Past Year’s Questions SB026

(a) This reaction takes place at which part of the chloroplast? [1 mark]
Thylakoid membrane/ grana/granum

(b) Name the substances labeled X and Y. [2 marks]

X : 2H+
Y : H2O/ water

(c) Name the centre of reaction at photosystem I and photosystem II. [2 marks]

Photosystem I : (Chlorophyll a) P700/ pigment P700
Photosystem II : (Chlorophyll a) P680/ pigment P680

(d) What is the function of NADPH produced in FIGURE 2? [1 mark]
As a reducing agent (during carbon fixation)

(e) The light dependent reaction involved are cyclic and non-cyclic photophosphorylation.

Name the first electron donor and the last electron acceptor for both processes.

[4 marks]

First e- donor Last e- acceptor

Cyclic photophosphorylation : photosystem I/P700/ photosystem I/P700/

none none

Non-cyclic photophosphorylation : water / H2O NADP+

Session 2005/2006
3 FIGURE 2 shows carbon fixation pathways in plants.

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PSPMCompilation of Biology Past Year’s Questions SB026

(a) Name the type of plant that use both cycles D and E. [1 mark]
C4 plant// CAM plant

(b) Name the substances labeled F, G and X. [3 marks]

F: Phosphoenolpyruvate
G: Malate/ malic acid
X: Carbon dioxide/ CO2

(c) Name the enzymes which catalyse the fixation of X in both cycles. [2 marks]

Enzyme for cycle D: PEP carboxylase// phosphoenolpyruvate carboxylase//
PEPCO
Enzyme for cycle E: RuBP carboxylase// ribulose bisphosphate

carboxylase// Rubisco

(d) State the name and function of Y. [2 marks]

Y: NADPH
Function: reducing agent// reducing oxaloacetate to G/malate/malic acid

(* mark for function is dependent on the correct name)

(e) How will hot and dry condition negatively affect the function of RUBP in plant

without cycle D? [2 marks]

Plant close the stomata to (conserve water)// CO2 is low
Rubisco fail to catalyse CO2 fixation to RuBP// RuBP fail to fix CO2// RuBP

bind to CO2

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2009/2010
4 FIGURE 3 shows the photosynthetic processes that occur in cell I and cell II.

(a) (i) Name the type of cell I and cell II. [2 marks]

Cell I: Mesophyll (cell)
Cell II: Bundle sheath (cell)

(ii) Name the molecules J and K. [2 marks]
Molecule J : Oxaloacetate/ Oxaloacetic acid/ OAA
Molecule K: Malate/ Malic acid

(iii) State the type of plants undergoes the process of photosynthesis

as in FIGURE 2. [1 mark]

C4 (plants)

(iv) State process L and name the enzyme that catalyses that process.
[2 marks]

Process L: Calvin cycle
Enzyme : Rubisco//RuBP carboxylase/oxygenase// Ribulose
bisphosphate carboxylase/oxygenase (* dependent on the process
L)

(b) (i) Name the process that occurs in cell II if carbon dioxide fixation process

is inhibited by oxygen. [1 mark]

Photorespiration

(ii) How does the process stated in (b)i lowers the efficiency of

photosynthesis

in cell II? [1 mark]

By reducing the formation of 3-phosphoglycerate/ 3-

phosphoglyceric acid/ 3-PGA molecules (dependent on the

process in b(i))

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PSPMCompilation of Biology Past Year’s Questions SB026

(c) State the type of plants that fix CO2 into organic acids at night and carry out the

light reaction during the day. [1 mark]

CAM / crussulacean acid metabolism (plants)

Session 2014/2015

3 FIGURE 3 shows carbon fixation and Calvin cycle in plant A and plant B.

FIGURE 3

(a) Both plants in FIGURE 3 have adaptations that facilitate carbon fixation. State

THREE factor that causes these adaptations. [3 marks]

Photorespiration

Hot and dry environment // arid environment // desert

The closure of stomata

(b) Name the types of separation adapted by plant A and plant B. [2 marks]
Plant A : Spatial separation (of steps) / split in space / place /location
Plant B : Temporal separation (of steps) // split in time

(c) Name the type of plant A and plant B in FIGURE 3. [2 marks]

Plant A: C4 plant.

Plant B : Crassulacean acid metabolism/ CAM plant

(d) Give ONE similarity and ONE difference based on carbon fixation between the

two types of plants in FIGURE 3. [2 marks]

Similarity : CO2 is first incorporated (by PEP) into oxaloacetate / OAA

// The enzyme used in the fixation of carbon in both

plants is PEP carboxylase // CO2 fixation occurs twice

Differences : In the C4 plant, carbon fixation takes place in the

mesophyll cells and bundle sheath cells. In CAM plant

carbon fixation occurs only in mesophyll cells.

(e) Give ONE example for plant B. [1 mark]
Cactus / pineapple

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2006/2007

(a) Describe the differences between C3 and C4 plants. [10 marks]
(b) Discuss how light intensity affects the rate of photosynthesis. [10 marks]

Session 2007/2008

(a) Describe light dependent reaction in photosynthesis. [8 marks]
(b) Describe the mechanism that reduces photorespiration in C4 plants. [12 marks]

Session 2008/2009

(a) Compare and contrast cyclic photophosphorylation and non-cyclic [12 marks]
photophosphorylation.

Session 2010/2011

(a) Discuss the non-cyclic photophosphorylation of light dependent reaction.[10 marks]
(b) Explain how plants convert CO2 from the atmosphere into a sugar molecule.

[10 marks]
Session 2011/2012

(a) Describe the electron flow through Photosystem II in plant. [10 marks]
(b) Describe carbon fixation in C4 plants. [10 marks]

Session 2013/2014

a) Describe the morphological and physiological differences between C3 plant and C4

plant. [10 marks]

(b) Describe carbon fixation in Calvin cycle for C3 plant. [10 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

18.0 GASEOUS EXCHANGE
Session PSPM 2006/2007
1 FIGURE 3 shows the chemical reaction of carbon dioxide transport in the blood.

FIGURE 3
(a) Name the part of haemoglobin molecule that binds to carbon dioxide.

[1 mark]
Amino group

(b) State the following advantages of erythrocyte characteristics that are related to

their functions.

(i) Generate ATP by anaerobic metabolism. [1 mark]

The transported oxygen is not consumed

(ii) The biconcave shape. [1 mark]
Increased surface area for diffusion of gas

(c) What are J, K, L and M in FIGURE 1? [4 marks]
J: Glucose// C6H12O
K: Carbonic anhydrase
L: Haemoglobinic acid// HHb
M: Chloride ion// Cl-

(d) What happen to HCO3- after undergoing process I? [1 mark]

Transported in the plasma // Transported to the lungs // Bind to sodium

(e) State the importance of process II and III. [2 marks]

II: To maintain electrochemical balance/ neutrality // to maintain charge

balance

III: To prevent the blood from becoming acidic (by H+) // act as a buffer

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2008/2009
2 FIGURE 3 shows structures found on leaves.

FIGURE 3

(a) State the importance of the whole structure shown above. [2 marks]

To regulate gaseous (O2 and CO2) exchange
To regulate water / transpiration / prevent water loss

(b) Name the structures labeled A and B. [2 marks]
A: Guard cell
B: Stoma/ Stomata/ Stomatal opening

(c) Name the organelle C and its function. [2 marks]
Organelle C: Chloroplast
Function: (To trap light energy for) photosynthesis

(d) State TWO hypotheses that explain how the whole structure functions.
[2 marks]

Starch-Sugar Hypothesis
Potassium Ion Hypothesis

(e) What will happen to B when A has [2 marks]
(i) high water potential
(Stoma) opens

(ii) high osmotic pressure
(Stoma) closes

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2015/2016
3 (a) FIGURE 1 below shows oxygen dissociation curves for human haemoglobin at

low and high partial pressure of carbon dioxide.

FIGURE 1
(i) From the graph, find the percentage oxygen saturation of haemoglobin

at high partial pressure of carbon dioxide at 5.2 kPa partial pressure of
oxygen.

[1 mark]
64%
(ii) State the shape of the dissociation curve at a low partial pressure of
carbon dioxide and explain briefly its relationship with haemoglobin
ability to transport oxygen from the lungs to respiring tissues.

[3 marks]
- In lungs high PO2 // low PCO2
- Hb has high affinity towards O2 / there is nearly 100%

saturation
- In respiring tissue, low PO2 // high PCO2
- Hb has low affinity towards O2 / Hb releases O2
(iii) Bohr effect is the release of oxygen by haemoglobin molecules in
response to high partial pressure of carbon dioxide. Explain briefly.

[1 mark]
- CO2 interacts with water forming carbonic acid
- dissociates into bicarbonate (HCO3-) and H+

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PSPMCompilation of Biology Past Year’s Questions SB026

- causes environment / surrounding / blood plasma to be more
acidic / more H+ / lower pH

- reduces haemoglobin’s affinity for oxygen // causing Hb to
release oxygen

- The curve will shift to the right
(iv) Sketch the oxygen dissociation curve of myoglobin in the same graph

on FIGURE 1.
[1 mark]

FIGURE 1.
(b) Nervous system regulates breathing in human.

(i) State the location of the respiratory control center in human.
[1 mark]

Medulla oblongata / Pons
(ii) A drop in pH is detected by chemoreceptors in the brain. State another

location in body where this type of chemoreceptor can be found.
[1 mark]

carotid and aortic body

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PSPMCompilation of Biology Past Year’s Questions SB026

Session 2003/2004

(a) What is meant by Bohr’s effect? Explain how Bohr’s effect occurs and its effect on

active tissues. [10 marks]

Session PSPM 2005/2006

(a) Describe how carbon dioxide is transported in the blood. [10 marks]

(b) With the aid of a labeled diagram, describe oxygen dissociation curve for

haemoglobin. [10 marks]

Session 2007/2008

(a) Describe the oxygen dissociation curves of haemoglobin and myoglobin with the

aid of a graph. [10 marks]

Session 2008/2009

(a) Describe the transport of carbon dioxide from tissues to the lungs in human.

[12 marks]

Session 2009/2010

(a) Explain how biconcave ion being converted back to carbon dioxide to remove

from the blood stream to the lung. [10 marks]

Session 2010/2011
(a) Describe the role of chemoreceptor in controlling human breathing rate.
[12 marks]

Session 2014/2015
(a) Describe the structures and functions of hemoglobin.
[10 marks]
(b) Explain the regulation of stomatal opening and closing based on starch-sugar
hypothesis.
[10 marks]

47

PSPMCompilation of Biology Past Year’s Questions SB026

19.0 TRANSPORT SYSTEM
Session 2013/2014
3 FIGURE 3 shows translocation of sucrose. The movement of molecules T and sucrose

are indicated by the arrows.

FIGURE 3

(a) Identify cell P, Q and molecule T. [3 marks]

P : Source/ leaf cells// mesophyll cells// companion cell
Q : Sink/ fruit/ root/ stem/ storage organ// companion cell
T : water

(b) Name TWO types of lateral pathways for the movement of sucrose from

P into the sieve tube. [2 marks]

Symplast
Apoplast

(c) What induce the movement of: [1 mark]
(i) Sucrose along the sieve tube?
Positive pressure/ hydrostatic pressure (of water)

(ii) Molecule T into the sieve tube? [1 mark]

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PSPMCompilation of Biology Past Year’s Questions SB026

High concentration of T/ water in U/ xylem// high osmotic pressure in
sieve tube// high water potential in U/ xylem// low water potential in
sieve tube

(d) What causes unloading of sucrose at Q? [1 mark]

Low osmotic pressure at Q (compared to sieve tube)// high water potential at

Q// high osmotic pressure in sieve tube// low water potential in sieve tube//

high sucrose concentration in sieve tube// low sucrose concentration at Q

(e) What would happen if the concentration of molecule T:

(i) Lower at the upper part of U? [1 mark]

T/ water cannot move to sieve tube// low hydrostatic pressure//
Translocation cannot occur// water move from lower part to upper part

(ii) Higher at the lower part of U? [1 mark]

T/ water can move to upper part// can move into sieve tube//
Translocation cannot occur// high hydrostatic pressure

Session 2003/2004 [10 marks]
(a) Explain the following terms.
(i) Cardiac cycle
(ii) Systole

(b) Explain the process involved and the path taken by water in plants starting from

soil to the endodermis. [5 marks]

(c) Explain briefly the types of pathway involved in the transport of water in (b).

[5 marks]

Session 2005/2006

(a) Explain the translocation of sucrose in plants. [7 marks]

(b) Discuss the uptake of minerals and water in vascular plants. [13 marks]

Session 2009/2010

(a) Describe the structure and functions of human lymphatic system related to the

lipid transportation. [10 marks]

(b) Explain the pathway of water being transported from surrounding soil to the

root vascular system in plant. [10 marks]

Session 2012/2013 [10 marks]
(a) Describe the mechanism of heart beat in mammals. [10 marks]
(b) Explain the translocation process in plants.

Session 2014/2015
(a) Discuss the pressure flow hypothesis of sugar translocation in phloem.
[12 marks]
(b) Describe the events in cardiac cycle that produces the ‘lub’ sound.
[8 marks]

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PSPMCompilation of Biology Past Year’s Questions SB026

20.0 HOMEOSTASIS
Session 2003/2004
1 FIGURE 2 and 3 show the regulation of water and Na+ of blood in the kidney.

(a) Identify P, Q and R. [3 marks]
P : Posterior pituitary gland
Q : Antidiuretic hormone / ADH
R : Aldosterone (hormone)

(b) Name the process A and B. [2 marks]
A : Negative feedback
B : Stimulation

(c) (i) Identify parts of the kidney on which hormone Q and R act. [2 marks]
Hormone Q : distal tubule
Hormone R : distal tubule

(ii) Explain how hormone Q lowers the blood osmotic pressure. [3 marks]

- Increase permeability of distal tubule and collecting duct to

water // distal tubule/collecting duct are more permeable to water

- Water moves out from tubule // water moves back into blood stream

- by osmosis

50