SKEMA JAWAPAN MOCK PSPM II PAPER 2

SB025/2 SB025/2
Biology 2 Biologi 2
Paper 2 Kertas 2
Semester 2 Semester 2
Session 2019/2020 Sesi 2019/2020
2 1/2 hour 2 1/2 jam

Name No Matrik

Tutorial Class Tutorial lecturer’s name

KOLEJ MATRIKULASI PAHANG
KEMENTERIAN PENDIDIKAN MALAYSIA

PAHANG MATRICULATION COLLEGE
MINISTRY OF EDUCATION MALAYSIA

MOCK PSPM II
KERTAS 2 (DUA)

2 1/2 JAM
2 1/2 HOUR

JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHU Marks
DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO /9
/7
Questions /7
/ 18
1 / 11
/7
ARAHAN KEPADA CALON: 2 / 11
Kertas soalan ini mengandungi 10 soalan. 3 /7
Jawab semua soalan yang disediakan dalam kertas soalan ini. 4 / 16
5 /7
Kalkulator elektronik boleh digunakan. / 100

INSTRUCTIONS TO CANDIDATE: 6
7
This question booklet consists of 10 questions. 8
Answer all questions provided in the question booklet. 9
The use of electronic calculator is permitted.

10

Total

Kertas soalan ini mengand1ungi 15 halaman bercetak.
This booklet consists of 15 printed pages.

1. (a) FIGURE 1 shows the zones of a deep freshwater lake.

FIGURE 1 [3 marks]
(i) Name zone P, Q and R.
[2 marks]
P : Littoral zone [1 mark]
Q : Limnetic zone
R : Profundal / Aphotic zone

(ii) State TWO physical criteria that classify zonation in lake.
- Based on light penetration
- Based on distance from shore

(iii) State ONE example of a primary consumer in zone Q.
Zooplankton

(b) FIGURE 2 shows two different types of growth curve.

Type A Type B

FIGURE 2

2

(i) Name Type A curve in FIGURE 2. [1 mark]
Exponential growth curve

(ii) State the growth rate and explain what happen in the phase R.

- Growth rate is rapid / exponential – MUST HAVE [2 marks]

- Abundant of resources

- No environmental resistance Any one

- Natality rate more than mortality rate

2. (a) FIGURE 3 shows a type of speciation within a beetle population.

FIGURE 3

(i) Define speciation. [1 mark]
Speciation is the formation of new species from pre-
existing species through evolution process

(ii) Identify the type of speciation outlined in the FIGURE 3. [1 mark]
Allopatric speciation

(iii) Why species A and B cannot be interbred? Give reason for your answer.
- Speciation has occurred // Species A and B are different [2 mark]
species.
- When species A and B come into contact, they do not
interbreed / they are reproductively isolated

3

(b) FIGURE 4 shows difference vegetables that diverge from one species of wild
mustard.

FIGURE 4

(i) Identify the type of selection in FIGURE 4. [1 mark]
Artificial selection

(ii) Briefly describe characteristics of selection in b(i). [2 marks]
- It is a planned event
- Selective breeding on organism showing desired traits Any
- Produce varieties of organism for a specific purpose 2

4

3. FIGURE 5 shows the reaction of enzyme M on substrate N.

FIGURE 5 [1 mark]
(a) What is cofactor?

Cofactor is a non-protein substance that is needed by enzymes
for normal activity.

(b) Based on the FIGURE 5, identify the type of cofactor for enzyme M.

Coenzyme [1 mark]

(c) Based on your answer in 3 (b), state its function in the enzymatic reaction.
Act as electron carrier (that transfer electrons, specific atoms [1 mark]
or functional groups in the reaction).

(d) According to International Union of Biochemistry (IUB), state the class of

enzyme M. [1 mark]

Oxidoreductases

(e) How enzyme M is affected when it is subjected to low temperature. [3 marks]

- (At low temperature,) the movement of molecules is slow/ the

kinetic energy of enzyme and substrate is low Any
- The number of collision between enzyme and substrate is low one
- Less enzyme-substrate complexes formed

- Thus, the rate of reaction is low

5

4. (a) FIGURE 6 shows one process that occurs in human cell.

FIGURE 6 [1 mark]
(i) State the location for the process in FIGURE 6. [2 marks]

Cytosol/ cytoplasm
(ii) Identify molecule C and molecule D in FIGURE 6.

Molecule C : Glyceraldehyde-3- phosphate
Molecule D : Pyruvate

(iii) Other than molecule D, state the net products for the process.

2 ATP and 2 NADH +2H+ [2 marks]

(iv) During this reaction, which molecule acts as the oxidising agent?

NAD+ [1 mark]

6

(b) Describe the processes of NADH formation when one molecule of glucose is

oxidised. [7 marks]

1. In glycolysis, glyceraldehyde-3-phosphate is oxidised, 1

reducing NAD+ to NADH + H+

2. and regenerating 1,3-bisphosphoglycerate. 1

3. In link reaction, pyruvate is oxidised, reducing NAD+ to 1

NADH + H+

4. and regenerating acetyl-CoA. 1

5. In Krebs cycle, Isocitrate is oxidised, reducing NAD+ to 1

NADH + H+ 1
6. and regenerating α-ketoglutarate. 1
7. α-ketoglutarate is oxidised, reducing NAD+ to NADH + H+

8. and regenerating succinyl-CoA. 1

9. Malate is oxidised, reducing NAD+ to NADH + H+ 1

10.and regenerating oxaloacetate. 1

Maximum: 10

Total : 7

(c) Explain the chemiosmosis process in oxidative phosphorylation.

[5 marks]

1. Greater concentration of H+ in the intermembrane space 1

compared to the matrix will create a proton motive force.

2. The proton motive force causes H+ flows back/ diffuse to 1

matrix of mitochondria through ATP synthase

3. Energy released is used to phosphorylate ADP to form ATP 1

4. Each NADH will produce 3 ATP 1

5. Each FADH2 will produced 2 ATP 1

7

5. (a) FIGURE 7 shows a schematic part of Calvin cycle occurs in stroma of
chloroplast.

FIGURE 7

(i) Identify Enzyme P and Molecule Q. [2 marks]
Enzyme P : Rubisco / RuBP Carboxylase-oxygenase
Molecule Q : Glyceraldehyde 3-phosphate

(ii) Explain the role of NADPH during in FIGURE 7.
[2 marks]

- (NADPH acts) as reducing agent
- Reduce 1,3-bisphosphoglycerate to glyceraldehyde 3-phosphate

(iii) Describe what happen to Molecule Q during PHASE 3.
[2 marks]

- Molecule Q / Glyceraldehyde 3-phosphate rearranges into RuBP /
ribulose bisphosphate

- By receiving phosphate group from ATP

8

(iv) Suggest what would happen to the amount of Molecule R produced

during autumn? Explain your answer. [2 marks]

- Less molecule R will be produced // Amount of

Molecule R will decreases

- Photosynthesis rate decreases due to leaves fall

(b) Briefly explain the process of photorespiration. [3 marks]

- Photorespiration is a process by which oxygen react with ribulose

bisphosphate (RuBP) catalysed by Rubisco.

- Producing a 2C compound, phosphoglycolate and 3C compound, 3-

phospholgycerate / PGA

- Reduces photosynthetic output // reduces the efficiency of photosynthesis

6. (a) FIGURE 8 shows the chemical reaction of carbon dioxide in the blood.

FIGURE 8

(i) Based on FIGURE 8, what will happen to the haemoglobin and

state its function. [2 marks]

- Haemoglobin will bind with hygrogen ion (H+) forming

haemoglobinic acid.

- The function is it acts as a buffer to prevent blood from becoming

acidic thus preventing Bohr shift.

9

(ii) Name process S and explain the significant of that process. [2 marks]

Process S : Chloride shift.
Function : To maintain the electrochemical neutrality or
charge balance of red blood cell

(b) Explain how exhalation occur. [3 marks]

- When lungs expand, stretch receptor in alveoli and bronchioles are

stimulated.

- Stretch receptors transmit impulses via vagus nerve to the expiratory

center in medulla oblongata.

- Internal intercostals muscle contract while external intercostals muscle

and diaphragm relax.

- Reduce the volume of thorax causing air forced out of the lung.

Any 3 marks

7. (a) FIGURE 10 shows the absorption of triglycerides into lacteal.

X FIGURE 10

(i) Structure X has a very large area that are exposed to the intestinal

lumen. Name structure X. [1 mark]

Microvillus

(ii) Give the significance of structure X. [1 mark]

Increase surface area for absorption of nutrients (in small intestine)

10

(b) FIGURE 11 shows the movement of water molecules in plant.

FIGURE 11

(i) Identify the mechanism of water transportation based on [1 mark]

FIGURE 11.
Cohesion – tension mechanism

(ii) Explain briefly the mechanism in (i). [2 marks]

- Adhesion is attractive force between water molecules and the xylem

walls due to the hydrogen bond

- Cohesion is attractive force between water molecules due to the

hydrogen bond

(c) Cardiac arrest is a leading cause of death. It triggered by an electrical

malfunction in the heart that causes an irregular heartbeat. Explain the

mechanism of heartbeat in cardiac conduction system. [6 marks]

1. Sinoatrial node generates electrical impulses. 1

2. Impulses spread rapidly through both atria’s walls, causing both 1

atria contract.

3. Impulses from sinoatrial node then reach atrioventricular node 1

4. and delayed at atrioventricular node for 0.1s. 1

5. Impulses from atrioventricular node travel through bundle of His to 1

Purkinje fibres.

6. Impulses then spread throughout the ventricular walls. 1

7. Both ventricles contract from apex upward, pumping blood into 1

aorta and pulmonary artery. Total : 7 marks, Max : 6 marks

11

8. FIGURE 12 shows a cross section of glomerulus.

Y

FIGURE 12

(a) Label X and Y? [2 mark]
X: filtration slit
Y: basement membrane

(b) State ONE factor that contribute to the efficiency of ultrafiltration [1 mark]
process.
- High hydrostatic blood pressure in the glomerulus/
- Highly coiled and long glomerulus capillaries/
- High permeability of the glomerulus

(c) How NaCl is transported along the ascending limb of loop of [2 marks]

Henle?

Thin segment: NaCl diffuse out / by passive transport

Thick segment: NaCl is actively transported out / by active transport

(d) What happen to the concentration of urine for animals that lives in [2 mark]
desert? Why?
They have more concentrated urine
They have long Loop of Henle

12

9. (a) FIGURE 13 shows a neuromuscular junction between a motor neuron and a
skeletal muscle.

X

FIGURE 13

(i) Name X and its content. [2 marks]

X : synaptic vesicle

Content : Acetylcholine

(ii) Explain events at sarcolemma after generation of action potential

occur. [3 marks]

- action potential then travels along the sarcolemma and spread

deep down through transverse tubule (T-Tubules).

- Depolarization of T tubule opens calcium channels

- in sarcoplasmic reticulum.

- Ca2+ is release into the muscle fiber. These lead to muscle

contraction. ANY 2

(c) FIGURE 16 shows a types of hormonal action process.

FIGURE 16

13

(i) State the type of hormone and hormone mechanism action in FIGURE
16. [2 marks]
Type of hormone : Steroid hormone
Mechanism action: Gene activation

(ii) Explain how second messenger (cAMP) hormone mechanism are
different from mechanism action in (i) in term of their effect.
- Mechanism (i) have short term effect while long term [2 mark]
effect
- Mechanism (i) response in a few minute while cAMP
take a longer time to response

(iii) How hormone as chemical messenger transported to its target cell?

Travel in bloodstream / transported in blood vessel [1 mark]

(d) Explain depolarization phase that leads to generation of an action potential

of axon membrane. [6 marks]

1. Presence of stimulus triggers the opening of some voltage- 1

gated Na+ channels

2. Na+ diffuses into axon down concentration gradients. 1

3. Influx of Na+ cause the membrane potential become less 1

negative inside axon // more positive than outside.

4. If voltage exceed -55mV / threshold level 1

5. This will trigger action potential (impulse) 1

6. It will cause the opening of more voltage-gated Na+ channels / 1

positive feedback.

7. More Na+ diffuses into axon. 1

Total : 9

Max : 6

14

6. FIGURE 17 shows three different B lymphocytes (K, L and M) and the clonal
selection of B cells that correspond to an immune response when exposed to an
antigen.

FIGURE 17

(a) State the type of immune response shown in FIGURE 17? [1 mark]
Humoral immune response

(b) State the type of nuclear division that occurs at X. [1 mark]
Mitosis

(c) (i) The clonal expansion of the B cells resulted in the production [4 marks]
of two pools of cells, cell A and cell B.
Cell A : Plasma cells
Function : Secretes antibodies against antigen
Cell B : Memory cells
Function : Rapidly proliferate upon subsequently exposure to the
same antigen.

(ii) What happen to both cells when infection is under control? [1 mark]
Memory cells remain in the body / ready to produce more
antibodies when needed.

SOALAN TAMAT

15