PraPSPM SARAWAK Biology SB025

TRIAL 1 BIOLOGY PSPM2 Name:____________________ Class:______

(a) Case A and Case B below describe the current situations of two species.

Case A: The last Sumatran rhinoceros, Dicerorhinus sumatrensis, died in
2019.

Case B: The population of adult Malayan tigers, Panthera tigris, keeps
declining over the year.

Kes A dan Kes B di bawah menghuraikan situasi semasa dua spesies.

Kes A: Badak sumbu Sumatera, Dicerorhinus sumatrensis, yang terakhir mati
pada tahun 2019.

Kes B: Populasi harimau Malaya, Panthera tigris, dewasa semakin
berkurangan dari tahun ke tahun.

Describe the threats faced by the animals in Case A and Case B. [4 marks]

(b) FIGURE 1 shows population growth curves.

Population size
Saiz populasi

E

Carrying capacity, K
Keupayaan muatan

F

FIGURE 1 Time
Masa

(i) Identify type of population growth curves for E and F.[2 marks]

(ii) How to maintain the maximum size of the population within the
carrying capacity (K)?[1 mark]

(a) Graphs P and Q in FIGURE 2 represent the original population distribution of
phenotypes before natural selection takes place.

Graf P dan graf Q dalam RAJAH 2 menunjukkan taburan fenotip populasi
asal sebelum pemilihan semula jadi berlaku.

No. of individuals No. of individuals
Bilangan individu Bilangan individu

Phenotypes Phenotypes

P Fenotip Q Fenotip

FIGURE 2

(i) Draw the new curves, on the above graphs, representing the distribution of
phenotypes after natural selection has taken place, with P shows a disruptive
selection and Q shows a stabilising selection.

Lukis keluk yang baru pada graf di atas, mewakili taburan fenotip selepas pemilihan
semula jadi berlaku, dengan P menunjukkan pemilihan disruptif dan Q menunjukkan
pemilihan penstabilan.

[2 marks]

(ii) Which of the curves drawn in 2(a)(i) represent the natural selection on the
seed-eating Galapagos finches. Give a reason for your answer.

Yang manakah di antara dua keluk dalam 2(a)(i) mewakili pemilihan semula jadi ke
atas burung ciak pemakan biji benih di kepulauan Galapagos. Beri satu alasan bagi
jawapan anda.

[2 marks]

2

(b) Two species of plants, Tradescantia canaliculata and T. subaspera flower at
different times of the year. What type of reproductive isolation has occurred to both
species?

Dua spesies tumbuhan, Tradescantia canaliculata dan T. subaspera, berbunga
pada masa berlainan dalam setahun. Apakah jenis isolasi pembiakan yang
berlaku kepada kedua-dua spesies?

[1 mark]
[1 markah]

2 FIGURE 3 demonstrates the induced fit mechanism between a substrate and an
enzyme in a catabolic reaction to form products C and D.

RAJAH 3 menunjukkan mekanisme padan teraruh antara substrat dan enzim dalam
tindak balas katabolik untuk membentuk hasil C dan D.

Substrate CD
Substrat

+

Enzyme
Enzim

FIGURE 3
RAJAH 3

(a) Draw the subsequent steps in the spaces provided.
Lukis langkah berikutnya di dalam ruang yang disediakan.

[2 marks]

(b) Based on the drawings in FIGURE 2A, explain the induced fit
mechanism (theory).

Berdasarkan lukisan pada RAJAH 2A, terangkan teori mekanisme padan
teraruh.

[3 marks]

3

(a) FIGURE 4 shows the Krebs cycle. Citrate
RAJAH 4 menunjukkan kitar Krebs. Sitrat
Acetyl CoA
Asetil KoA

Oxaloacetate
Oksaloasetat

Malate J
Malat

-ketoglutarate
K -ketoglutarat

Succinate Succinyl CoA
Suksinat Suksinil KoA
L

FIGURE 4

(i) Identify J and K.

J: [2 marks]
K:
[2 marks]
(ii) Describe process L. [2 markah]
Huraikan proses L.

4

(iii) Based on FIGURE 3, what is the total number of NADH and FADH2
produced?
Berdasarkan RAJAH 3, berapakah jumlah bilangan NADH dan
FADH2 yang dihasilkan?
[2 marks]
[2 markah]

(b) Explain how 38 ATP is obtained when one molecule of glucose undergoes
complete oxidation and substrate level phosphorylation
Terangkan bagaimana 38 ATP diperoleh apabila satu molekul glukosa
melalui pengoksidaan lengkap dan .
[8 marks]
[8 markah]

(a) Photosynthesis involves light dependent and light independent reactions.
Fotosintesis melibatkan tindak balas bersandar cahaya dan tindak balas
tidak bersandar cahaya.
(i) State the products of light dependent reaction required for light
independent reaction.
Nyatakan hasil tindak balas bersandar cahaya yang diperlukan untuk
tindak balas tidak bersandar cahaya.
[2 marks]
[2 markah]

(ii) Describe the formation of oxygen during light independent reaction.
Huraikan pembentukan oksigen semasa tindak balas bersandar
cahaya.
[5 marks]

5

(b) Briefly explain the events that can decrease the yield of C3 plants.

Terangkan secara ringkas peristiwa yang boleh mengurangkan hasil
tumbuhan C3.

[2 marks]
[2 markah]

3 FIGURE 6 shows a schematic diagram of the control of breathing.

Inspiration
Inspirasi

Stretch receptor [H+] detected by Effectors
Reseptor regangan chemoreceptor Efektor

[H+] dikesan oleh No impulse
kemoreseptor Tiada impuls

Respiratory center
Pusat respirasi

Stretch receptor Expiration Effectors
Reseptor regangan Ekpirasi Efektor

FIGURE 6
RAJAH 6

(a) Name the location of the control center in the brain in FIGURE 6 [1 mark]

(b) Name the two (2) effectors that receive input from the control center.[2 marks]

6

(c) Briefly explain the control of inspiration by the respiratory center. [3 marks]

4 FIGURE 7 shows the electrical activity of the heart recorded using a device.
RAJAH 7 menunjukkan aktiviti elektrik jantung yang direkodkan menggunakan
sejenis alat.

FIGURE 7
RAJAH 7

(a) Name the device used.
Namakan alat yang digunakan.

[1 mark]
[1 markah]

(b) What event occur in heart that is shown by P wave?

Apakah peristiwa yang berlaku pada jantung yang digambarkan oleh
gelombang P?

[1 mark]
[1 markah]

(c) Describe the activity of the heart at P.
Terangkan aktiviti jantung pada P.

[4 marks]
[4 markah]

7

(d) Briefly describe the QT interval in FIGURE 7.
Jelaskan dengan ringkas sela masa QT pada RAJAH 7.

[2 marks]
[2 markah]

(e) Name the artery that supply oxygenated blood to the cardiac muscle.
Namakan arteri yang membekalkan darah beroksigen ke otot kardiak.
[1 mark]

5 FIGURE 8 shows the results on glucose tolerance test. Two subjects (normal and
diabetic) were administered glucose solution. Their blood glucose levels were
determined hourly.

RAJAH 8 menunjukkan hasil ujian toleransi glukosa. Dua subjek (normal dan
pengidap diabetes) diberi minum larutan glukosa. Aras glukosa dalam darah mereka
diukur setiap jam.

Blood glucose concentration 400 Diabetic
Kepekatan glukosa dalam darah 350 Pengidap diabetis
300
(mg/100 mL) 250 Normal
200
150 12345 6
100
50 Hours after glucose intake
Jam selepas pengambilan glukosa
0
0

FIGURE 8
RAJAH 8

(a) Based on FIGURE 8, determine the normal blood glucose level.

8

Berpandukan RAJAH 8, tentukan aras normal glukosa dalam darah.
[1 mark]

[1 markah]

(b) Briefly explain the negative feedback reduction of glucose level in the normal
subject.
Terangkan secara ringkas suap balik negatif penurunan aras glukosa dalam
subjek normal.
[3 marks]
[3 markah]

(c) Give two (2) suggestions why the above diabetic fails to control his blood
glucose level.[2 marks]

(a) FIGURE 9 shows two neurones and one synapse. The value of electrical potential
difference across the membrane is stated in the figure.

RAJAH 9 menunjukkan dua neuron dan satu sinaps. Nilai perbezaan
keupayaan elektrik merentasi membran dinyatakan dalam rajah.

Z
Y
FIGURE 9
RAJAH 9

9

(i) Show the direction of the movement of impulse along the nerve fibre
using an arrow on FIGURE 9.

Tunjukkan arah pergerakan impuls di sepanjang gentian saraf dengan
menggunakan satu anak panah pada RAJAH 9. [1 mark]

(ii) Name structures Y and Z. State their respective functions in impulse
transmission.

Namakan struktur Y dan struktur Z. Nyatakan fungsi masing-masing
dalam penghantaran impuls.

[4 marks]

Structure Y Structure Z
Struktur Y Struktur Z

Name
Nama

Function
Fungsi

(iii) Draw a circle on FIGURE 9 where action potential occurs. Give a
reason for your answer.

Lukiskan satu bulatan pada RAJAH 9 di mana keupayaan tindakan
berlaku. Beri satu alasan bagi jawapan anda.

[2 marks]
[2 markah]

(iv) How are the charges along the axon maintained after the action
potential is triggered.

Bagaimanakah cas di sepanjang akson dikekalkan selepas keupayaan
tindakan tercetus.

[2 marks]
[2 markah]

(b) Compare steroid and protein hormones actions.
10

Bandingkan tindakan hormon steroid dan protein.

[4 marks]
[4 markah]

6 FIGURE 10 shows graph of antibody concentration of immune response after
exposure to pathogens.

Antibody concentration in serum Second exposure to antigen
AntiKbeopdekyactoancaennttirbatoidoindianlasemrusemrum Pendedahan kedua kepada antigen

(Ar(biAtrrabrityaruynitu)nit) First exposure to Q
antigen

Pendedahan pertama
kepada antigen

PP

Time (days)
Masa (hari)
FIGURE 10
(a) Identify the types of antibody represented by P and Q.[2 marks]

P:
Q:
(b) Based on your answer in 10(a), how do P and Q differ in immune response for
first exposure? [1 mark]

11

(c) Describe how antibodies provide protection against pathogen.[3 marks]
12