Perfect Score Bio Answer

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PERFECT SCORE BIOLOGY 2011

BAHAGIAN SEKOLAH BERASRAMA PENUH DAN
SEKOLAH KLUSTER
KEMENTERIAN PELAJARAN MALAYSIA

PERFECT
SCORE
BIOLOGY

2011

Teacher’s Module

1

PERFECT SCORE BIOLOGY 2011
Paper 2 – Section A:
Structural Questions
1.

Marks

Student
notes

Diagram 1.1 shows a somatic cell of an insect undergoing meiosis. Process X

R: Centromere
Q: Chromosome/
chromatid

S: Nuclear
membrane

Diagram 1.1
(a)

Label Q, R and S in Diagram 1.1.
[3 marks]

(b)

3m

In the space below draw chromosome behaviour during metaphase I and metaphase II.

2m
Metaphase I

Metaphase II

[2 marks]

2

PERFECT SCORE BIOLOGY 2011
(c)

Explain how the process X involves in producing variation in organisms. P1 - During prophase Meiosis 1, crossing over occurs between homologous chromosomes
Any
3=3m

P2 - resulting a new genetic combination.
P3-

(d)

It is also producing the exchange of genetic material between paternal chromosome and maternal chromosome // between
homologous chromosomes.
[3 marks]

Diagram 1.2 shows the formation of an ovum.

Oogonium (2n)

Primary oocyte (2n)

M
M
First polar body
(n)

Secondary oocyte
(n)

N
N

Second polar body
(n)
Diagram 1.2
(i)

What are process M and N?
M : Meiosis I
N : meiosis II
[2 marks]

(ii)

2m

Describe the process that occurs if a sperm present at process N. P1: meiosis II completed // ovum form
P2: (nucleus) ovum is fertilized by sperm nucleus
2m

P3 : zygote is form
[2 marks]

3

PERFECT SCORE BIOLOGY 2011
2.

Diagram 2 shows the digested food is being carried from small intestine to the liver and body cell.

Diagram 2

(a)(i)

Name process X at the villus.
Absorption
[1 mark]

(ii)

1m

Explain ONE adaptation of the villus for the process in (a)(i). F : Has thin wall//one cell thick wall
E : Diffusion of nutrient occurs rapidly //

F: Has network of blood capillary

1F=1m
1E=1m

E : transport nutrient to body tissue

4

PERFECT SCORE BIOLOGY 2011
F : has lacteal //
E : to absorb/ transport fatty acid/glycerol to body tissue

F : numerous
E : increase total surface area
(b)

[2 marks]
Vessel P and Q transport digested food from the villi to the liver and body cells respectively.
Name vessel P and vessel Q.
P :Hepatic portal vein

1m

Q: Lymphatic vessel
[2 marks]
(c)

1m

Explain what happens to the excessive amino acids in the liver? P1 : Excess amino acid is converted into urea

1m

P2 : process is called deamination
[2 marks]
(d)

1m

Digested food are used by the body cells for growth, to form complex compounds or structural components.
State how lipids, amino acid and glucose are used in the cell. Lipids:
L1: is used to build up plasma membrane/phospolipid
L2 : excess lipid is stored in adipose tissue
L=1m

L3 : is used as energy reserve in the body

A=1m

Amino acids:

G=1m

A1: Amino acids are used in protein synthesis
A2 : to repair damage tissue
A3: used in synthesis of enzyme/hormones/antibody
Glucose:
G1 : is used in cellular respiration/ is oxidized to release energy G2 : Glucose is stored as adipose tissue.
[3 marks]

5

PERFECT SCORE BIOLOGY 2011
(e)

Explain what will happen to a person if his liver receives insufficient insulin from the pancreas.
P1 : Blood sugar level increases// Diabetes mellitus

1m

P2 : Excess glucose cannot be converted to glycogen

1m
[2 marks]

3.

Diagram 3 shows the structure of respiratory system in human.

Bronchus

P

Alveolus

Blood
capillary

Cells
Diagram 3
(a)

Based on Diagram 3, explain one adaptation of alveolus for efficient gases exchange.
F1 : one cell thick
P1 : gas doesn’t have far to diffuse //diffuse easily
F2 : supply with network of blood capillary.
P2 : to increase the diffusion // transportation of respiratory gases to /from all the body cells.

1F=1m
1P=1m

F3 : large surface area // numerous...
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