How to Answer Biology SPM

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Version 1.1 An e-book by Kenneth Ng SMK KOLOMBONG KOTA KINABALU 2008

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Disclaimer : This e-book is meant to be used as a guide to help teachers prepare their students to sit for the SPM exams. It is provided free of charge on a 'best intention ' basis. The author shall not be held responsible for any inaccuracies contain therein or any outcome arising from the use of this e-book. Condition of use: This e-book may be distributed in its original form free of charge. It is not to be sold for any profit. Kenneth Ng

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BIOLOGY 1 Read the entire question and all the answer choices before deciding on the answer. Mark your answer clearly on the Objective Answer Sheet . If you cannot answer a question, go on to the next question . Remember to come back to this question later . This will prevent you from wasting precious time. Go through your answers after you have finished. You might want to change some of your answers.

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BIOLOGY 2 - STRUCTURED QUESTIONS Write neatly and clearly. Be brief and to the point - it is not necessary to repeat the question. Show your working for any calculation work. (Write down the formula, substitute the values into the formula , complete the calculation ). Use a pencil to draw diagrams or graphs. Label diagram and graphs clearly. Use the marks allocated to determine how much you should write. One mark is allocated for one point. Use the instruction guide to answer the questions.

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BIOLOGY 2 - ESSAY QUESTIONS Read all the questions before choosing those that you want to answer. Re-read the chosen questions carefully to make sure you are interpreting them correctly. You may explain your answer using appropriate diagrams (be sure to label all diagrams), equations, graphs, tables or any other suitable methods. Give your answers according to the key instruction words . Use the INSTRUCTION GUIDE below. You may give your answer in point form. Check the number of points in your answer with the number of marks allocated for the question. (One point is usually allocated one mark). If possible give one or two more points than the maximum marks allocated.

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INSTRUCTION GUIDE AND RESPONSE Key instruction word Answer What is  ? Give the actual name. Spelling for scientific terms and names must be accurate. How many Give the quantity, no need for calculation calculate Show the workings of your calculation and the final answer Name Give the correct name, scientific names must be underlined State Just give the fact. No explanations or descriptions needed. List State the facts in point form. Define Define the term clearly and completely.

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INSTRUCTION GUIDE AND RESPONSE Key instruction word Answer Why Give the reasons How Explain step by step how it takes place Compare Give the similarities and differences explicitly. Use a table. What are the differences Give the differences explicitly. Use a table. Describe Tell the story, an account of, state the main points of the topic. No elaborate explanation of why and how is necessary Discuss Give your opinion from different aspects, viewpoints or arguments.

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INSTRUCTION GUIDE AND RESPONSE Key instruction word Answer Contrast / Distinguish Give the differences only. Evaluate Give the positive and negative aspects. Explain Clarify what, how or why. State the fact followed by a few sentences to elaborate it. Illustrate Explain or clarify by using diagrams, drawings or figures. Outline Briefly give the important points. Summarize Present concisely all main points. Tick ( ) in the box Tick ( ) in the box, DO NOT use a cross ( ).

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Describe the graph As the temperature increase from 0 o C to 40 o C , the rate of enzyme activity also increases. The rate of enzyme activity is maximum at 40 o C . As the temperature increases above 40 o C , the rate of enzyme activity decreases.

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Explain the graph As the temperature increase from 0 o C to 40 o C , the rate of enzyme activity also increases . At these temperatures, the enzyme is more active as the temperature increases because the rate of collision between the enzymes and the substrate molecules increases with the increase of temperature. The rate of enzyme activity is maximum at 40 o C because this temperature is optimum for the enzyme to function. As the temperature increases above 40 o C , the rate of enzyme activity decreases because the enzymes begin to denature due to the high temperature.

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PAPER 3 : QUESTION 1 The following scientific skills are tested in Question 1: OBSERVATION QUESTION : State two observations  . ANSWER : Write down what can be observed only. Do not do any analysis, comparison or conclusion. For most experiments , the observation can be written in the form: The  .(responding variable)  .. at  ..(manipulated variable )  is (state reading of measuring instrument ) ( Write the observation for the highest and lowest value of the responding variable.) Example: The time taken for the starch to be completely hydrolysed at 5 o C is 45 minutes. The time taken for the starch to be completely hydrolysed at 40 o C is 5 minutes .

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INFERENCE State one inference which corresponds to each observation. An inference is a brief explanation of the observation, based on scientific knowledge which you already know. Example: The time taken for starch to be completely hydrolysed at 5 o C is 45 minutes because the low temperature causes the enzymes to react slowly with the substrate . The time taken for starch to be completely hydrolysed at 5 o C is 5 minutes because the higher temperature causes the enzymes to react quickly with the substrate. 3 . MEASURING AND USING NUMBERS Record the reading of thermometer, stopwatch, ruler etc. from the given diagram .

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4 . COMMUNICATING Construct the table with the manipulated variable as the first column and the responding variable as the second column. Data derived or calculated from the second column can be added to the third column. Show the calculations in the third column itself. Units of measurements should be written together with table titles, not with readings. Example Temperature / o C Time for starch to be completely hydrolysed / min Rate of reaction / min -1 5 10 1/10 = 0.1 15 5 1/5 = 0.2 30 2 ½ = 0.5

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5. INTERPRETING DATA Explain / state the relationship between manipulated and responding variables as obtained from a graph of the results. Example: As the temperature increases from 5 o C to 45 o C , the time taken for the complete hydrolysis of starch decreases from 45 minutes to 5 minutes.

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6. CONTROLLING VARIABLES Variables State the variable Describe how you control the variables Use action words and name the instruments used MANIPULATED Temperature Use /  . Use a thermometer to measure the temperature of the water bath and add ice or warm water to maintain the temperature of the water bath. Place the test tubes in the different water baths. RESPONDING Time taken for complete hydrolysis of starch Record / measure using  . Record the time taken for the enzyme substrate mixture to lose its blue colour . CONTROLLED Concentration of Enzyme Use the same  / Maintain  Use the same amount of enzyme ( 1 ml) in each of the experiment.

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7 . MAKING HYPHOTHESIS Able to state the hypothesis correctly based on the following criteria : • State the manipulated variable • State the responding variable • Relate the manipulated variable and the responding variable (do not use vague relationships like 'affects‘ or 'influence' or 'changes with'). Commit to using terms like: 'increases with' / 'decreases with' .

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8. PREDICTING QUESTION : If the experiment is repeated  .., predict the observation  ANSWER : Give a value or relevant statement e.g. the ( responding variable) will be higher / lower than (the value in the first experiment) followed by a the reason  EXAMPLE : What will the rate of transpiration be at fan speed 3 , if the experiment is repeated in the dark? The transpiration rate at fan speed 3 will be less then (value recorded) because the stomata is closed in the dark and less water will be loss through them.

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9 . DEFINING OPERATIONALLY Give a definition based on the context of the experiment. EXAMPLE 1: An experiment is carried out to investigate photosynthesis and the number of bubbles released is counted . The operational definition of photosynthesis would then be: Photosynthesis is the process where green plants release bubbles in the presence of light, carbon dioxide and water. EXAMPLE 2: An experiment is carried out to investigate photosynthesis and leaves are tested with iodine solution for the presence of starch. The operational definition of photosynthesis would be: Photosynthesis is the process where green leaves in the presence of light, carbon dioxide and water, produce starch which turns iodine solution dark blue.

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EXAMPLE 3: An experiment is carried out to investigate transpiration under different fan speeds. The operational definition of transpiration would be: Transpiration is the process where a plant loses water to the surrounding which is indicated by the movement of water or air bubble in the capillary tube and is affected by speed of the air current. (You should include the variables in the context of the experiment / experimental conditions .)

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10 . CLASSIFYING Group the materials or apparatus listed using a table with the headings provided. Group them according to their function in the experiment. 11 . USING SPACE-TIME RELATIONSHIP State the changes of the responding variable with time. Use relationship words like increases with / decreases with / remains constant with / increases proportionately with / etc. Do not use neutral relationship terms like affects / influences / changes with.

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PAPER 3 : QUESTION 2 This question tests student's ability to plan an experiment in a given format. Students must have all of the following : Problem statement Aim of investigation /Objective Variables Hypothesis List of apparatus and materials Technique used Experimental procedure or method Presentation of data Conclusion

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PROBLEM STATEMENT Must be written in the form of a question - End with a question mark. Eg . Does pH affect the activity of amylase? AIM OF INVESTIGATION /OBJECTIVE Write down the objective as given in the question. Eg . To investigate the effect of pH on the activity of amylase? VARIABLES Write down 3 variables. (Manipulated variable, responding variable and controlled variable. The controlled variable must be one that will affect the outcome of the experiment if not kept constant.)

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HYPOTHESIS Able to state the hypothesis correctly based on the following criteria : • State the manipulated variable • State the responding variable • Relate the manipulated variable and the responding variable LIST OF APPARATUS AND MATERIALS List down all the materials and apparatus used. TECHNIQUE USED In a complete sentence, write down what is observed or measured (include the instrument used). State the specific name of the technique where applicable. Example : Measure and record the volume of fruit juices needed to decolorize blue DCPIP , using a syringe. Measure and record the initial and final temperature of the water in the boiling tube using a thermometer.

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EXPERIMENTAL PROCEDURE OR METHOD Write down each step clearly and systematically. Your steps should include: Steps where you describe how apparatus and materials are handled. Steps where you describe how the controlled variable is maintained Steps where you describe how the manipulated variable is altered Steps where you describe how the responding variable is measured and the instrument to be used. Precautionary steps which ensure safety / improve accuracy of readings. ( write the steps as a set of instructions or direct speech and not in passive speech)

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PRESENTATION OF DATA Construct the table with the correct titles and units. Leave the table blank. The experiment is not carried out yet, so the results are not yet available. CONCLUSION Repeat or modify the hypothesis sentence. You may then write whether the hypothesis is accepted or rejected. The roots of education are bitter, but the fruit is sweet. Aristotle