2 INFORMATION FOR CANDIDATES 1. This question paper consists of two questions. Answer all questions. 2. Write your answers for Question 1 in the spaces provided in the question paper 3. Write your answers for Question 2 on the lined pages at the end of the question paper in detail. You may use equations, diagrams, tables, graphs and other suitable methods to explain your answer. 4 Show your working, it may help you to get marks 5 If you wish to cancel any answer, neatly cross out the answer. 6 The diagrams in the questions are not drawn to scale unless stated. 7 Marks allocated for each question or part question are shown in brackets 8 The time suggested to complete Question 1 is 45 minutes and Question 2 is 45 minutes 9 You may use a non-programmable scientific calculator 10 Hand in this question paper at the end of the examination. Marks awarded Score Description 3 Excellent: The best response 2 Satisfactory: An average response 1 Weak: An inaccurate response 0 No response or wrong response Answer all questions. Question 1 1. An experiment is conducted to investigate the effect of environmental factors on the colonisation of Mucor sp. (fungi) on bread. Three slices of bread are used. Each of the slices is damped with water every day for 5 days and kept in different physical conditions. After five days, the population coverage area of Mucor sp. on the bread slices are observed as shown in Diagram 1. A quadrat of 10 cm X 10 cm is used to estimate the coverage area of Mucor sp. population. Grid lines are drawn to divide the quadrat into 100 small boxes. The area of each box is 1 cm 2 . The coverage area of Mucor sp. population on the bread is estimated as 1 cm 2 when it covers more than half of the box. [Satu eksperimen telah dijalankan untuk mengkaji kesan faktor persekitaran terhadap pengkolonian oleh Mucor sp. (fungi) di atas roti.. Tiga keping roti digunakan. Setiap roti di lembapkan dengan air setiap hari selama 5 hari dan disimpan dalam keadaan fizikal yang berbeza. Selepas 5 hari keluasan kawasan litupan Mucor sp diperhatikan seperti yang ditunjukkan dalam Rajah . Satu kuadrat 10cmX10cm digunakan untuk menganggar luas kawasan litupan populasi Mucor sp. Garisan grid dilukis untuk membahagikan kuadrat kepada 100 petak kecil. Luas setiap petak ialah 1cm 2 . Luas litupan Mucor sp.di atas roti adalah dianggarkan 1cm 2 bila meliputi lebih dari separuh petak.]
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INFORMATION FOR CANDIDATES 1. This question paper consists of two questions. Answer all questions. 2. Write your answers for Question 1 in the spaces provided in the question paper 3. Write your answers for Question 2 on the lined pages at the end of the question paper in detail. You
may use equations, diagrams, tables, graphs and other suitable methods to explain your answer. 4 Show your working, it may help you to get marks 5 If you wish to cancel any answer, neatly cross out the answer. 6 The diagrams in the questions are not drawn to scale unless stated. 7 Marks allocated for each question or part question are shown in brackets 8 The time suggested to complete Question 1 is 45 minutes and Question 2 is 45 minutes 9 You may use a non-programmable scientific calculator 10 Hand in this question paper at the end of the examination. Marks awarded
Score Description
3 Excellent: The best response
2 Satisfactory: An average response
1 Weak: An inaccurate response 0 No response or wrong response
Answer all questions. Question 1 1. An experiment is conducted to investigate the effect of environmental factors on the
colonisation of Mucor sp. (fungi) on bread. Three slices of bread are used. Each of the slices is damped with water every day for 5 days and kept in different physical conditions. After five days, the population coverage area of Mucor sp. on the bread slices are observed as shown in Diagram 1. A quadrat of 10 cm X 10 cm is used to estimate the coverage area of Mucor sp. population. Grid lines are drawn to divide the quadrat into 100 small boxes. The area of each box is 1 cm2. The coverage area of Mucor sp. population on the bread is estimated as 1 cm2 when it covers more than half of the box. [Satu eksperimen telah dijalankan untuk mengkaji kesan faktor persekitaran terhadap pengkolonian oleh Mucor sp. (fungi) di atas roti.. Tiga keping roti digunakan. Setiap roti di lembapkan dengan air setiap hari selama 5 hari dan disimpan dalam keadaan fizikal yang berbeza. Selepas 5 hari keluasan kawasan litupan Mucor sp diperhatikan seperti yang ditunjukkan dalam Rajah . Satu kuadrat 10cmX10cm digunakan untuk menganggar luas kawasan litupan populasi Mucor sp. Garisan grid dilukis untuk membahagikan kuadrat kepada 100 petak kecil. Luas setiap petak ialah 1cm
2. Luas
litupan Mucor sp.di atas roti adalah dianggarkan 1cm2 bila meliputi lebih dari separuh petak.]
3
[Scale: 1 box = 1 cm2 ] [Skala: 1 petak = 1 cm
2 ]
Place P – A well-lighted place on the laboratory table [Tempat P - atas meja makmal yang cukup cahaya ]
Place Q – in the refrigerator with temperature 5ºC Tempat Q – di dalam peti sejuk bersuhu 5ºC]
Place R - A dark place in a cupboard [Tempat R – tempat gelap dalam almari]
Number of boxes covered by Mucor sp [Bilangan petak yang dilitupi oleh Mucor sp]
………………… boxes [petak]
Number of boxes covered by Mucor sp [ Bilangan petak dilitupi oleh Mucor sp]
……………………… boxes [petak]
Number of boxes covered by Mucor sp [ Bilangan petak dilitupi oleh Mucor sp]
……………………… boxes [petak]
Diagram 1 [Rajah 1]
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Based on Diagram 1, answer the following questions [Berdasarkan Rajah 1, jawab semua soalan berikut]
1(a)(i) State two observations on the area covered by the Mucor sp
[Nyatakan dua pemerhatian tentang kawasan yang dilitupi oleh Mucor sp]
(b)(i) Record the number of boxes covered by the Mucor sp on each bread in the space provided in Diagram 1. [Catatkan bilangan petak dilitupi oleh Mucor sp di atas setiap kepingan roti dalam ruang yang disediakan dalam Rajah 1].
[3 marks]
1(a)(i)
(a)(ii)
(b)(i)
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(b)(ii) Tabulate the result of the experiment based on the following criteria: [Jadualkan keputusan eksperimen berdasarkan kriteria berikut]
• Physical condition of the bread [keadaan fizikal roti ]
• Number of boxes [bilangan petak] • Coverage area [luas litupan]
[3 marks]
(b)(iii) What is the relationship between the physical condition of the bread and the area covered by Mucor sp. in this experiment? [Apakah hubungan antara keadaan roti dengan luas litupan oleh Mucor sp dalam eksperimen ini?]
(f) The experiment is repeated by using milk instead of water to damp the bread. Predict the area covered by Mucor sp. on the bread in Place R. [Ekperimen ini diulang dengan menggunakan susu menggantikan air untuk melembapkan roti. Ramalkan luas litupan Mucor sp di atas roti pada tempat R ]
(g) Arrange the environmental factor of bread from the most favourable condition to the least favourable condition for the growth of Mucor sp. [Susun keadaan fizikal roti dari keadaan yang paling sesuai kepada yang tidak sesuai untuk pertumbuhan Mucor sp.]
[3 marks]
[33 marks]
(g)
(f)
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2. Diagram 2 shows three types of fruits. [Rajah 2 menunjukan tiga jenis buah-buahan]
Plan a laboratory experiment to investigate the percentage of vitamin C content in each fruit. DCPIP (dichlorophenolindophenol) 0.1% solution is used to test the presence of vitamin C in the fruit juices. You can use the common chemicals and science apparatus that can be found in the laboratory. Your report should include:
[Rancang satu eksperimen dalam makmal untuk mengkaji peratusan kandungan vitamin C dalam setiap buah. Larutan DCPIP 0.1% digunakan untuk menguji kehadiran vitamin C dalam jus buah. Anda boleh menggunakan bahan kimia dan radas sains yang biasa digunakan dalam makmal Laporan anda hendaklah mengandungi perkara-perkara berikut:]
• Problem statement [Peryataan masalah]
• Aim of experiment [Tujuan eksperimen]
• Variables [Pembolehubah]
• Hypothesis [Hipotesis]
• Apparatus and materials [Radas dan Bahan]
• Technique [Teknik]
• Procedures [Kaedah]
• How data is communicated [Bagaimana data dikomunikasikan]
Able to state any two observations correctly according to 2 criteria:
• Environmental factor of the bread
• Area covered Sample answers: 1. In the place P, well-lighted place (on the laboratory table) the boxes covered
is 19(20) boxes 2. In the place R, the dark place (bread in the cupboard) the boxes covered is
39(40) boxes 3. In the place Q, in the refrigerator at temperature 5ºC, the boxes covered is
3(4) boxes. 4. In the place R, the dark place (bread in the cupboard) the boxes covered is
more than in well-lighted place 5. In the place R, the dark place (bread in the cupboard) the boxes covered is
more than in the refrigerator.
2 Able to state any one observation correctly. or
Able to state any two incomplete observations ( any 2 criteria) Sample answers: 1. In the well lighted place on the laboratory table the area covered is less/
small .
2. In the dark place (bread in the cupboard) the area covered is more/ large . 3. In the refrigerator, the area covered is small/least . 4. Different environmental factor will cause different size of area covered.
1 Able to state any one idea of observation.(any 1criteria) Sample answers: 1. Breads are place in different environmental factors. 2. The light effects the area covered. 3. Temperature affects the area covered. Or any other suitable answer.
0 Not able to response or wrong response.
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1 (a) (ii) [KB0604 - Making inferences] Score Criteria
3 Able to make one logical inference for each observation based on the criteria
• Condition of bread • Favourable for Mucor sp growth
Sample answers: 1. Well lighted place is not suitable favourable for Mucor sp to grow 2. Darker place is condusive for Mucor sp to grow/ favourable/most suitable condition for growth. 3. Cool place is not condusive for Mucor sp to grow
2 Able to make one logical inference for any one observation.
or Able to make one logical and incomplete inference base on one criteria for each observation. Sample answer:
1. Different condition will causes different growth rate of Mucor sp. 2. Well lighted place is suitable for Mucor sp to grow. 3. Darker place is the most suitable place. 4. Cool place is not suitable. 5. Temperature affect the Mucor sp growth rate.
1 Able to make an idea of inference with one criteria. Sample answers
1. Mucor sp able to grow on bread 2. Mucor sp will grow in different condition 3. Mucor sp not grow in low temperature. 4. Light affect Mucor sp growth.
0 Not able to response or wrong response. (b)(i) [KB0606 – Communicating]
Score Criteria 3
Able to draw a table with all columns and rows labeled with complete unit Sample answers
Environmental factor. Number of boxes Area covered [cm2]
Place P/ In well lighted place Place R/ In dark place Place Q/ in refrigerator
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2 Able to draw a table with 2 label of column. 1 Able to draw a table with 1 label of column 0 Not able to response or wrong response.
(b)(ii) [KB0603 – Measuring Using Number]
Score Criteria 3
Able to calculate and record all the area covered by Mucor sp. Sample answers
Environmental factor Number of boxes Area covered [cm2]]
Place P/ In well lighted place 19 19 Place R/ In dark place 39 39 Place Q/ in refrigerator 3 3
2 Able to calculate and record 4 - 5 number of boxes and area covered
1 Able to calculate and record 2 - 3 number of boxes and area covered
0 Able to give one number of boxes and area covered response, no response or wrong response.
3 Able to state clearly and accurately the relationship between the environmental factor and size of area covered by Mucor sp. based on the criteria:
• Environmental factor • Coverage area of Mucor sp.
• Suitable for growth
Sample answer:
1. In the dark place the Mucor sp. coverage area is the largest because dark condition is the most suitable place to grow.
2. In the well-lighted area the Mucor sp. coverage is less because the well lighted place is less suitable place to grow.
3. In the refrigerator, the coverage is small because cool condition is not suitable for Mucor sp growth.
2 Able to state clearly but less accurate the relationship between the condition of
bread and size of area covered by Mucor sp.
Sample answer:
1. In the well-lighted area the Mucor sp. coverage is smaller/less than in the dark area place.
2. In the well-lighted area the Mucor sp. coverage is small because the well lighted condition is not a suitable place to grow
3. In the cool area the Mucor sp. coverage is smaller/less than in the dark area.
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4. The larger size of the Mucor sp coverage show the more suitable condition for Mucor sp to grow.
1 Able to state the idea of the relationship . 1. Coverage area depends on the condition of the bread 2. Different condition affect the Mucor sp. coverage on bread. 3. Temperature affect the growth of Mucor sp. 4. Mucor sp growth effected by bread condition.
0 Not able to response or wrong response.
(c) [KB061001 – Controlling Variables]
Variables How the variables are operated Manipulated: Environmental factor
Bread slices are placed in three different conditions/ in well-lighted place, dark place and refrigerator.
Responding: Coverage area
Count the boxes and calculate the area coverage using the scale given/ 1cm2 each box.
Fixed: Type of bread/ time taken
Using the same type of bread for all condition/ The observation is done after 5 days.
[Each answer = 1 mark] (d) [KB0611- Making Hypothesis]
Score Criteria 3 Able to state a hypothesis to show a relationship between the manipulated
variable and responding variable and the hypothesis can be validated, base on 3 criteria:
• manipulated variable
• responding variable • relationship
Sample answer : 1. In the dark place, the area coverage by Mucor sp. Is the largest. 2. In well- lighted place, the area coverage by Mucor sp. is smaller than in
the dark place. 3. In the refrigerator/ low temperature, the area coverage by Mucor sp. is
the least.
2 Able to state less accurate hypothesis to show a relationship between manipulated variable and responding variable base on 2 criteria. Sample answer
1. Different place has different size of Mucor sp. area coverage
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2. Different condition has different coverage area of Mucor sp 3. Temperature/light affect the size of the area covered by Mucor sp.
1 Able to state idea of hypothesis to show a relationship between manipulated variable and responding variable base on 1 criterion. Sample answer
1. The area coverage is varied 2. Mucor sp can survive in different condition 3. Temperature affect the Mucor sp growth 4. Light affect the Mucor sp growth
3 Able to explain the colonisation operationally base on 3 criteria: • Mucor sp (pioneer organism)
• inhibit (successfully)
• bread (new habitat)
Sample answer: 1. Colonisation is the process of Mucor sp firstly/successfully inhabit/
populate the new bread.
2 Able to state the colonisation process base on 2 criteria. Sample answer:
1. Colonisation is the process of Mucor sp inhabit/ live on the bread. 2. Colonisation is when the bread is inhabit successfully by organism.
1 Able to state the idea of the colonisation or the theoretical definition of colonization or hypothesis.
1. Colonisation is the process of pioneer species successfully inhibit/ populate the new habitat.
2. Colonisation is the process inhibition of new bread. 3. The process where Mucor sp grow on bread.
0 Not able to response or wrong response.
(g) [KB0605 – Predicting]
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Score Criteria 3 Able to predict the result accurately base on 3 criteria.
• Expected area coverage (more than place R) • Compare to which
• The reason of the answer
Sample answer: The coverage area is 40 /above 40 cm2 is more than area coverage in place R, because milk contain sufficient nutrient for higher rate of Mucor sp growth. .
2 Able to predict the result less accurate base on 2 criteria Sample answer: 1. The area coverage is more than in place R, because milk have nutrient for Mucor sp to grow rapidly. 2. The area coverage is 40 cm2 more than in place R. 3. The area coverage is different, more than in place R because milk have nutrient for Mucor sp to grow rapidly
1 Able to give idea of the result base on 1 criterion. Area coverage is more/ is 40 cm2 The area coverage is more than R Milk have more nutrient for Mucor sp to grow faster. The area coverage is different from in the place R
0 Not able to response or wrong response.
(i) [KB0602 – Classifying] Score Criteria
3
Able to classify the physical conditions of bread from the most favorable to Mucor sp to the least favorable. Sample answer Condition
1 Place R 2 Place P 3 Place Q
2
Able to classify 2 conditions
1 Able to classify 1 condition
0 Not able to response or wrong response.
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QUESTION 2
Aspect Criteria Score
KB061201 Identifying Problem Statement
Able to write a problem statement correctly base on 3 criteria:
• Manipulated variables
• Responding variables • Question relationship.
Sample Answer 1. What is the percentage of vitamin C content in
watermelon, orange and apple?/ fruits? 2. Does apple/orange/watermelon contain more vitamin C than orange/watermelon/apple? 3. Which fruit has more percentage of vitamin C?
3
Able to write a problem statement but less correctly base on 2 criteria.
2
Able to give an idea about the problem statement base on 1 criteria.
1
Wrong or no response
0
Objective
Able to state the objective of the experiment correctly Sample Answer
1. To determine the percentage of vitamin C in watermelon, orange and apple/ given fruits. 2. To investigate the percentage of vitamin C in watermelon, orange and apple/ given fruits.
√
Aspect Criteria Score
Variables
Able to identify all the three variables correctly Sample Answer
• Manipulated variable : type of fruit • Responding variable : percentage of vitamin C
• Fixed variable : concentration of DCPIP / volume of DCPIP
√
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Aspect Criteria Score
KB061202 Making hypothesis
Able to write a suitable hypothesis correctly base on the 3 criteria:
• Manipulated variable • Responding variable
• Relationship
Sample Answer Watermelon has highest content of vitamin C compare to other fruits. Orange has the highest content of vitamin C. Apple has the lowest content of vitamin C. [note: wrong hypothesis is accepted]
3
Able to write a hypothesis but less correctly base on the 2 criteria.
2
Able to give an idea about the problem statement base on 1 criterion.
1
No response
0
Aspect Criteria Score
KB061205 Materials and Apparatus
Able to list all materials and apparatus needed to carry out the experiment successfully. Sample Answer Materials : DCPIP solution (M) Standard Ascorbic Acid Fruit juices / watermelon juice/orange juice/apple juice Apparatus : Conical flask /beaker (A) Syringe with needle Specimen tube All M and A
3
Materials : DCPIP solution Standard Ascorbic Acid Fruit juices Apparatus : Syringe with needle Specimen tube
All M and A without beaker/container
2
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Materials : DCPIP solution Standard Ascorbic Acid Fruit juices Apparatus : Syringe with needle
All M and A without beaker/container and specimen tube
1
Incomplete list or wrong or no response
0
Aspect Criteria Score
Technique
Able to state the technique used in carrying out the experiment correctly Sample Answer Calculate percentage of vitamin C content using formula :
B1 = 1
Aspect Criteria Score
KB061204 Procedure
Able to write all the steps in carrying out the experiment successfully. K1 : Steps to set up the apparatus K2 : Steps to handle the fixed variable K3 : Steps to handle the manipulated variable K4 : Steps to handle the responding variable K5 : Precautionary steps / steps taken to get accurate results / readings
Scoring Rubric All K1-K5 present
3
Any 3 – 4K present
2
Any 2K present 1
Percentage of Vitamin C (M1) = M2 X V2 V1 M1 = concentration of fruit juice. M2 = concentration of standard ascorbic acid. V1 = the volume of fruit juice V2 = the volume of standard ascorbic acid.
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Sample Answer Procedure Notes
K1 1. Three specimen tubes is labeled as A1, A2 and A3.
K2 2. Filled each specimen tubes with 1 ml of 0.1% DCPIP solution
K1 3 . Use a syringe to take 10 ml of standard ascorbic acid
K1 4 . Place the syringe needle into the DCPIP solution and release
the ascorbic acid slowly into the DCPIP solution in A1
K4 5 Observe the change of DCPIP colour and stop releasing the
ascorbic acid when the DCPIP become colourless/ no more blue
traces
K4 6 Record the volume of ascorbic acid used to dicolourised the
DCPIP.
K1/K5 7 Repeat step 3 – 6 for A2 and A3 and calculate the average volume.
K1/K5 8 Juices from each of the fruits is obtained and keep it fresh before used
K1/K2 9 Three specimen tubes is labeled as (B1, B2, B3, C1, C2, C3, D1, D2 and D3), and fill each specimen tubes with 1 ml of 0.1% DCPIP
K3 10 Repeat the step 2 – 7 by using fruit juices to replace the standard ascorbic acid.
K5 11 Do not shake the bottle to prevent from DCPIP is oxidated.
K4 12 Record the volume of watermelon juice, apple juice and orange juice that discolourised the DCPIP in the table and calculate the average volume
K4 13 Calculate the percentage of vitamin C in each of the fruit 5K = 3 m
1K or wrong response [√] is given for any 1K present.
0
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juice using the formula below:
3-4K = 2 m
1-2K = 1 m
Aspect Criteria Score
Communi-cating data
Able to draw a complete table to record the relevant data base on the 3 criteria:
• Type of juices • Juice volume (cm3)
• Percentage of ascorbic acid in juices (%) Sample Answer Type of juices DCPIP
volume (cm3)
Juice volume (cm3)
Percentage of ascorbic acid in juices (%)
Standard Ascorbic Acid
Apple juice
Orange juice
Watermelon juice
B2 = 1
Able to draw a complete table to record the relevant data with 2 criteria
2
Able to draw a table to record the relevant data but incomplete with 1 criterion.
1
Wrong or no response
0
Percentage of vitamin C = volume of 0.1% ascorbic acid X 1.0mgcm
-1
in fruit juice volume of fruit juice
23
Aspect Criteria Score
Conclusion
Able to write a suitable conclusion for the experiment: Sample Answer Watermelon has higher content of vitamin C compare to other fruits or Orange has the highest content of vitamin C or Apple has the lowest content of vitamin C.
√
Hypothesis accepted // Hypothesis rejected only
No tick
Aspect Criteria Score
KB061203 Experimen- ting
Able to write a complete report for the experiment. Scoring Rubric 8 – 9 aspects correct