O–Level Biology P-6 ATP Notes Article # 208
Features: Comprehensive notes and guidance for each topic Methods of attempting ATP questions Every experiment is followed by result and discussions for better understanding of phenomenon Practice sections include classified past papers 2010-17 Unseen exam based sample questions included
Author:
Muhammad Shahid Salamat International Campus for Advance Studies (SICAS-SLC)
Review Board: Asad Jamil Zafar Sulehri Hamid Fiaz
(LGS, Beaconhouse, Ex. Head of Deptt. Aitchison College) (LGS, Beaconhouse, SICAS, The City School) (LGS, The City School, LACAS, SICAS)
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Title
Biology P-6 O-Level ATP Notes
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Muhammad Shahid Cell: +92 334 4463339
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O-LEVEL ATP NOTES
1
Introduction
Contents Introduction to ATP paper ................................................................................................ 10 Unit 1: Cells ....................................................................................................................... 12 Preparing a temporary slide of onion epidermis cells ...................................................... 12 Observing the effect of surface area on rate of diffusion.................................................. 13 Practice Questions related to Cells ................................................................................. 14 Sample Question (1) ................................................................................................... 14 Sample Question (2) ................................................................................................... 14 Sample Question (3) ................................................................................................... 15 Sample Question (4) ................................................................................................... 15 Sample Question (5) ................................................................................................... 16 Unit 2: Diffusion and Osmosis ......................................................................................... 20 Observing the effect of temperature on diffusion ............................................................. 20 Observing the effect of concentration gradient and distance on diffusion ........................ 20 Observing the effect of particle size on diffusion.............................................................. 21 Observing osmosis across partially permeable membrane .............................................. 21 Observing effect of water and sugar solution on potato tissue (Method 1) ....................... 22 Observing effect of water and sugar solution on potato tissue (Method 2) ....................... 23 Observing plasmolysis .................................................................................................... 23 Observing the effects of varying the concentration of sucrose solution on potato tissue .. 24 Observing the partial permeable ability of a membrane ................................................... 25 Practice Questions related to Diffusion and Osmosis ................................................... 26 Sample Question (1) ................................................................................................... 26 Oct/Nov 2011-P61 ....................................................................................................... 27 Oct/Nov 2013-P62 ....................................................................................................... 28 Unit 3: Food Tests ............................................................................................................. 32 Tests for Carbohydrates .................................................................................................. 32 Tests for Fats (The Ethanol Emulsion Test) .................................................................... 32 Tests for Proteins (The Biuret Test)................................................................................. 32 Observing presence of vitamins ...................................................................................... 33 Practice Questions related to Food Tests ....................................................................... 34 May/June 2012-P61, Q3.............................................................................................. 34 May/June 2012-P62, Q3.............................................................................................. 35 May/June 2013-P61, Q1.............................................................................................. 36 May/June 2013-P62, Q2.............................................................................................. 38 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
2
Introduction
May/June 2014-P61, Q2.............................................................................................. 38 May/June 2015-P61, Q1.............................................................................................. 39 Oct/Nov 2012-P61, Q4 ................................................................................................ 40 Oct/Nov 2013-P61, Q4 ................................................................................................ 40 Oct/Nov 2016-P61, Q2 ................................................................................................ 41 Oct/Nov 2014-P62, Q3 ................................................................................................ 41 Oct/Nov 2015-61, Q1 .................................................................................................. 41 Oct/Nov 2016-P62, Q1 ................................................................................................ 42 Unit 4: Application of Enzymes ........................................................................................ 44 Characteristics of Enzymes ............................................................................................. 44 Extracting and testing enzyme from living cells ............................................................... 44 Observing the effect of temperate on enzyme activity ..................................................... 45 Observing the effect of pH on enzyme activity ................................................................. 46 Practice Questions related to Application of Enzymes .................................................. 48 May/June 2015-P61, Q1.............................................................................................. 48 May/June 2015-P62, Q3.............................................................................................. 50 May/June 2016-P61, Q1.............................................................................................. 51 Oct/Nov 2011-P62, Q1 ................................................................................................ 52 Oct/Nov 2012-P61, Q1 ................................................................................................ 54 Oct/Nov 2012-P62, Q1 ................................................................................................ 57 Unit 5: Photosynthesis ..................................................................................................... 62 Testing starch in a leaf .................................................................................................... 62 Testing the necessity of chlorophyll for photosynthesis ................................................... 62 Testing the necessity of light for photosynthesis.............................................................. 63 Testing the necessity of carbon dioxide for photosynthesis ............................................. 63 Testing the production of oxygen as result of photosynthesis .......................................... 63 Testing the effect of varying light intensity on rate of photosynthesis (Method 1)............. 64 Testing the effect of varying light intensity on rate of photosynthesis (Method 2)............. 65 Testing the effect of varying carbon dioxide concentration on rate of photosynthesis. ..... 66 Testing the effect of changing temperature on rate of photosynthesis ............................. 67 Observing the importance of different mineral elements in plant growth .......................... 68 Practice Questions related to Photosynthesis ............................................................... 69 Sample Question (1) ................................................................................................... 69 Sample Question (2) ................................................................................................... 70 Sample Question (3) ................................................................................................... 71 Sample Question (4) ................................................................................................... 72 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
3
Introduction
Sample Question (5) ................................................................................................... 73 Unit 6: Nutrition in Human ................................................................................................ 76 Calculating the energy from food sample ........................................................................ 76 Observing the action of salivary amylase on starch ......................................................... 76 Modelling the action of salivary amylase on starch .......................................................... 77 Testing the action of pepsin on egg-white protein............................................................ 78 Observing the action of lipase ......................................................................................... 79 Practice Questions related to Nutrition in Humans ........................................................ 80 Sample Question (1) ................................................................................................... 80 Sample Question (2) ................................................................................................... 81 Sample Question (3) ................................................................................................... 83 Sample Question (4) ................................................................................................... 83 Unit 7: Transport in Plants ............................................................................................... 86 Observing transport in vascular bundles of plant stem .................................................... 86 Observing transport of water in xylem ............................................................................. 86 Observing water loss by plant ......................................................................................... 86 Observing rate of water uptake by plant under varying environmental conditions ............ 87 Observing which surface of leaf loses more water........................................................... 88 Practice Questions related to Transport in Plants.......................................................... 90 Sample Question (1) ................................................................................................... 90 Unit 8: Transport in Humans ............................................................................................ 92 Observing and dissecting sheep’s or goat’s heart ........................................................... 92 Observing the effect of exercise on pulse rate ................................................................. 93 Practice Questions related to Transport in Humans ...................................................... 94 Sample Question (1) ................................................................................................... 94 Sample Question (2) ................................................................................................... 95 Sample Question (3) ................................................................................................... 97 Sample Question (4) ................................................................................................... 97 Unit 9: Respiration .......................................................................................................... 100 Observing oxygen in exhaled air ................................................................................... 100 Observing carbon dioxide in exhaled air ........................................................................ 100 Calculating the volume of air in lungs ............................................................................ 101 Investigating the effect of exercise on carbon dioxide production .................................. 101 Observing the usage of oxygen during respiration (Method I)........................................ 102 Observing the usage of oxygen during respiration (Method II)....................................... 103 Observing anaerobic respiration by yeast ..................................................................... 104 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
4
Introduction
Practice Questions related to Respiration .................................................................... 105 Sample Question (1) ................................................................................................. 105 Sample Question (2) ................................................................................................. 106 Sample Question (3) ................................................................................................. 107 Sample Question (4) ................................................................................................. 109 Unit 10: Germination ....................................................................................................... 112 Observing the effect of temperature on rate of respiration of germinating seeds ........... 112 Observing the release of energy as result of respiration ................................................ 112 Investigating the need of water for germination (Method 1) ........................................... 113 Investigating the need of water for germination (Method 2) ........................................... 113 Investigating the need of suitable temperature for germination...................................... 114 Experimental and Control Group ................................................................................... 114 Practice Questions related to Germination ................................................................... 115 Sample Question (1) ................................................................................................. 115 Sample Question (2) ................................................................................................. 115 Sample Question (3) ................................................................................................. 117 Unit 11: Drawings and Labelling .................................................................................... 120 Parameters of making a larger drawing and labelling it ................................................. 120 Practice Questions of Drawings and Labelling ............................................................. 121 May/June 2010-P61, Q3............................................................................................ 121 May/June 2010-P62, Q1............................................................................................ 121 May/June 2010-P62, Q1............................................................................................ 122 May/June 2011-P62, Q3............................................................................................ 123 May/June 2011-P62, Q3............................................................................................ 124 May/June 2012-P61, Q2............................................................................................ 125 May/June 2012-P61, Q3............................................................................................ 126 May/June 2012-P62, Q2............................................................................................ 127 May/June 2015-P62, Q2............................................................................................ 128 May/June 2016-P61, Q2............................................................................................ 129 Oct/Nov 2012-P61, Q2 .............................................................................................. 130 Oct/Nov 2013-P61, Q3 .............................................................................................. 132 Oct/Nov 2014-P62, Q2 .............................................................................................. 132 Oct/Nov 2016-P61, Q2 .............................................................................................. 134 Oct/Nov 2016-P62, Q1 .............................................................................................. 135 Unit 12: Drawings and Magnification ............................................................................. 138 How to work out magnification and other sizes of drawings/Images .............................. 138 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
5
Introduction
Practice Questions of Drawings and Magnification ..................................................... 140 May/June 2010-P61, Q2............................................................................................ 140 May/June 2011-P61, Q3............................................................................................ 141 May/June 2011-P62, Q3............................................................................................ 141 May/June 2012-P62, Q3............................................................................................ 142 May/June 2014-P61, Q2............................................................................................ 143 May/June 2014-P62, Q2............................................................................................ 145 May/June 2015-P61, Q2............................................................................................ 147 May/June 2015-P61, Q3............................................................................................ 148 May/June 2015-P62, Q1............................................................................................ 149 Oct/Nov 2010-P61, Q2 .............................................................................................. 150 Oct/Nov 2010-P62, Q2 .............................................................................................. 151 Oct/Nov 2011-P61, Q1 .............................................................................................. 152 Oct/Nov 2011-P61, Q2 .............................................................................................. 153 Oct/Nov 2012-P62, Q2 .............................................................................................. 154 Oct/Nov 2013-P62, Q1 .............................................................................................. 155 Oct/Nov 2014-P61, Q2 .............................................................................................. 156 Oct/Nov 2015-P61, Q1 .............................................................................................. 158 Oct/Nov 2015-P61, Q2 .............................................................................................. 159 Oct/Nov 2015-P62, Q2 .............................................................................................. 160 Oct/Nov 2016-P61, Q2 .............................................................................................. 161 Oct/Nov 2016-P62, Q1 .............................................................................................. 161 Unit 13: Features of a Photograph or Drawing ............................................................. 164 Recognizing and observing features of a photograph or drawing .................................. 164 Practice Questions of Features of a Photograph or Drawing ...................................... 165 May/June 2010-P61, Q1............................................................................................ 165 May/June 2011-P61, Q3............................................................................................ 165 May/June 2011-P62, Q2............................................................................................ 166 May/June 2011-P62, Q3............................................................................................ 167 May/June 2012-P61, Q2............................................................................................ 168 May/June 2012-P61, Q3............................................................................................ 168 May/June 2015-P62, Q2............................................................................................ 169 May/June 2012-P62, Q1............................................................................................ 169 May/June 2012-P62, Q4............................................................................................ 171 May/June 2013-P61, Q2............................................................................................ 172 May/June 2013-P62, Q2............................................................................................ 172 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
6
Introduction
Oct/Nov 2010-P61, Q2 .............................................................................................. 173 Oct/Nov 2010-P61, Q3 .............................................................................................. 174 Oct/Nov 2010-P62, Q1 .............................................................................................. 175 Oct/Nov 2010-P62, Q1 .............................................................................................. 176 Oct/Nov 2011-P61, Q2 .............................................................................................. 177 Oct/Nov 2011-P62, Q2 .............................................................................................. 178 Oct/Nov 2012-P61, Q2 .............................................................................................. 179 Oct/Nov 2012-P61, Q3 .............................................................................................. 180 Oct/Nov 2012-P62, Q2 .............................................................................................. 181 Oct/Nov 2012-P62, Q3 .............................................................................................. 182 Oct/Nov 2013-P61, Q2 .............................................................................................. 183 Oct/Nov 2013-P61, Q3 .............................................................................................. 184 Oct/Nov 2014-P61, Q3 .............................................................................................. 185 Oct/Nov 2015-P61, Q2 .............................................................................................. 186 Oct/Nov 2016-P61, Q1 .............................................................................................. 187 Oct/Nov 2016-P62, Q1 .............................................................................................. 188 Oct/Nov 2016-P62, Q1 .............................................................................................. 188 Unit 14: Graph ................................................................................................................. 190 Constructing and interpreting graph .............................................................................. 190 Specific guidelines for a bar chart ................................................................................. 190 Specific guidelines for a histogram ................................................................................ 191 Specific guidelines for a line graph ................................................................................ 191 Specific guidelines for a pie chart .................................................................................. 191 Practice Questions related to Graph ............................................................................. 192 May/June 2010-P61, Q1............................................................................................ 192 May/June 2011-P62, Q3............................................................................................ 193 May/June 2013-P61, Q2............................................................................................ 194 May/June 2013-P62, Q2............................................................................................ 195 May/June 2016-P61, Q1............................................................................................ 196 Oct/Nov 2014-P61, Q2 .............................................................................................. 198 Oct/Nov 2016-P62, Q3 .............................................................................................. 200 Practice Questions for Making Graph and then Suggesting or Concluding............... 203 May/June 2010-P62, Q3............................................................................................ 203 May/June 2011-P61, Q2............................................................................................ 204 May/June 2014-P61, Q2............................................................................................ 206 May/June 2014-P62, Q1............................................................................................ 208 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
7
Introduction
Oct/Nov 2010-P61, Q1 .............................................................................................. 211 Oct/Nov 2010-P62, Q1 .............................................................................................. 212 Oct/Nov 2011-P61, Q3 .............................................................................................. 214 Oct/Nov 2013-P61, Q1 .............................................................................................. 216 Oct/Nov 2013-P62, Q3 .............................................................................................. 219 Oct/Nov 2014-P62, Q1 .............................................................................................. 222 Oct/Nov 2015-P61, Q1 .............................................................................................. 225 Oct/Nov 2015-P62, Q1 .............................................................................................. 226 Unit 15: Water and Carbon Dioxide ............................................................................... 230 Testing Presence of Carbon dioxide with Hydrogen carbonate Indicator ....................... 230 Testing Presence of Water with Cobalt Chloride Paper ................................................. 230 Practice Questions Related to Testing of Water and Carbon Dioxide......................... 231 May/June 2013-P62, Q3............................................................................................ 231 May/June 2015-P61, Q2............................................................................................ 231 May/June 2015-P62, Q2............................................................................................ 232 Oct/Nov 2010-P62, Q3 .............................................................................................. 232 Oct/Nov 2014-P61, Q1 .............................................................................................. 234 Unit 16: Observations and Deductions.......................................................................... 236 Techniques to record observations and making deductions .......................................... 236 Practice Questions Related to Observations and Deductions..................................... 237 May/June 2012-P61, Q1............................................................................................ 237 May/June 2012-P62, Q2............................................................................................ 238 May/June 2015-P62, Q1............................................................................................ 239 Oct/Nov 2013-P62, Q1 .............................................................................................. 241 Unit 17: Designing and Planning ................................................................................... 244 How to design and plan an investigation ....................................................................... 244 Practice Questions Related to Designing and Planning .............................................. 245 May/June 2010-P61, Q1............................................................................................ 245 May/June 2010-P62, Q1............................................................................................ 245 May/June 2011-P61, Q1............................................................................................ 246 May/June 2011-P62, Q3............................................................................................ 247 May/June 2012-P61, Q1............................................................................................ 247 May/June 2013-P61, Q2............................................................................................ 248 May/June 2013-P61, Q3............................................................................................ 249 May/June 2014-P62, Q2............................................................................................ 250 May/June 2015-P61, Q1............................................................................................ 250 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
8
Introduction
May/June 2016-P61, Q1............................................................................................ 251 Oct/Nov 2010-P61, Q3 .............................................................................................. 251 Oct/Nov 2011-P61, Q1 .............................................................................................. 252 Oct/Nov 2012-P62, Q2 .............................................................................................. 252 Oct/Nov 2015-P61, Q3 .............................................................................................. 253 Oct/Nov 2015-P62, Q3 .............................................................................................. 254 Unit 18: Suggestions and Improvements ...................................................................... 258 Recommending suggestions and making improvements in experimentation ................. 258 Practice Questions Related to Suggestions and Improvements ................................. 259 May/June 2010-P61, Q1............................................................................................ 259 May/June 2010-P62, Q1............................................................................................ 259 May/June 2010-P61, Q2............................................................................................ 260 May/June 2010-P62, Q3............................................................................................ 261 May/June 2011-P62, Q1............................................................................................ 261 May/June 2011-P62, Q3............................................................................................ 263 May/June 2012-P61, Q2............................................................................................ 264 May/June 2014-P62, Q1............................................................................................ 264 May/June 2015-P61, Q3............................................................................................ 265 May/June 2015-P62, Q1............................................................................................ 266 May/June 2015-P62, Q2............................................................................................ 267 Oct/Nov 2010-P61, Q3 .............................................................................................. 268 Oct/Nov 2015-P61, Q1 .............................................................................................. 269 Oct/Nov 2015-P61, Q3 .............................................................................................. 270 Oct/Nov 2016-P62, Q2 .............................................................................................. 271 Unit 19: Interpreting Data and Drawing Conclusion ..................................................... 274 Basis of interpreting data and drawing conclusion form that .......................................... 274 Practice Questions Related to Interpreting Data and Drawing Conclusion ................ 275 May/June 2010-P61, Q2............................................................................................ 275 May/June 2010-P62, Q2............................................................................................ 276 May/June 2013-P62, Q1............................................................................................ 277 May/June 2014-P61, Q1............................................................................................ 280 May/June 2015-P61, Q2............................................................................................ 282 May/June 2016-P61, Q3............................................................................................ 283 Oct/Nov 2013-P62, Q2 .............................................................................................. 284 Oct/Nov 2014-P61, Q1 .............................................................................................. 287 Oct/Nov 2016-P61, Q1 .............................................................................................. 289 Home Delivery# 0321-1100570
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O-LEVEL ATP NOTES
9
Introduction
Unit 20: Practice Questions related to Measurements ................................................. 292 May/June 2012-P61, Q3............................................................................................ 292 May/June 2015-P62, Q1............................................................................................ 293 May/June 2012-P62, Q1............................................................................................ 294 Oct/Nov 2015-P61, Q1 .............................................................................................. 295 Oct/Nov 2015-P62, Q1 .............................................................................................. 296 Oct/Nov 2016-P61, Q2 .............................................................................................. 297 Oct/Nov 2014-P62, Q2 .............................................................................................. 298 Oct/Nov 2016-P61, Q3 .............................................................................................. 299 Oct/Nov 2016-P62, Q3 .............................................................................................. 300
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O-LEVEL ATP NOTES
10
Introduction
Introduction to ATP paper In O-Level Biology ATP paper (P-VI) is equally important as P-I and P-II. It carries 40 marks. According to the instructions in syllabus document ATP paper could be categorized into some key ideas and on basis of these ideas students’ abilities could be assessed in the paper (assessment objectives related to ATP given below). Those ideas have been separated with mentioned details of the concept and some clues on the assessment of the same ideas in the past papers are also mentioned along with that. Have a look at these categories and their details given here in this booklet. Also realize yourself that a significant proportion of your ATP assessment would be unfamiliar; so that needs a lot of practice and applying learnt concepts in different and difficult context. Further booklet gives all possible experiments from your syllabus and moreover results and discussion provides an analysis of your interpretation as expected by the examiner. In accordance to that ideology if you are projecting for A* then simply practice all the questions (given in practice section) but after reading relevant theory and practical section. Assessment objectives of CIE The Alternative to Practical is designed to test candidates’ abilities:
to follow carefully a sequence of instructions. to describe familiar and suggest unfamiliar techniques to record observations and make deductions from them. to recognize and observe features of photographs and drawings of familiar and unfamiliar biological specimens, record their observations and make deductions about functions of whole specimens or their parts. to make clear line drawings of the images of specimens, indicate magnification and to label familiar structures. to interpret unfamiliar data and draw conclusions from their interpretations. to design/plan an investigation to solve a problem. to comment on a procedure used in an experiment and suggest an improvement. to observe images of reactions; read from photographs, diagrams and simple measuring instruments, and perform simple arithmetical calculations. to measure to an accuracy of 1 mm, using a ruler. to describe simple physiological experiments, involving tests for food substances, enzyme reactions, hydrogen carbonate indicator solution, cobalt chloride paper. to describe simple physiological experiments.
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O-LEVEL ATP NOTES
11
Unit-2: Diffusion and Osmosis
Topics Unit-1 Preparing a temporary slide of onion epidermis cells. Observing the effect of surface area on rate of
Cells
diffusion.
O Level
Biology ATP NOTES Muhammad Shahid Cell: 0334-4463339 muhammadshahid2u@gmail.com
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O-LEVEL ATP NOTES
12
Unit-2: Diffusion and Osmosis
Unit 1: Cells Preparing a temporary slide of onion epidermis cells The onion provides a very useful source of epidermal plant tissue which is one cell thick, making it relatively easy to set up as a temporary slide. The onion is made up of fleshy leaves. On the incurve of each leaf there is an epidermal layer which can be peeled off.
By using forceps, peel a piece of epidermal tissue from the incurve of an onion bulb leaf.
Place the epidermal tissue on a glass microscope slide.
Use a scalpel, cut out a 1 cm square of tissue and arrange it in the centre of the slide.
Add two to three drops of iodine solution. (This will stain any starch in the cells and provides a contrast between different components of the cells.)
Use a forceps, a mounted needle or a wooden splint to support Cover slip with one edge resting near to the onion tissue, at an angle of about 45°.
Gently lower the cover slip over the onion tissue, trying to avoid trapping any air bubbles.
Leave the slide for about 5 minutes to allow the iodine stain to react with the specimen. The iodine will stain the cell nuclei pale yellow and the starch grains blue.
Place the slide on to the microscope stage, select the lowest power objective lens and focus on the specimen. Increase the magnification using the other objective lenses.
Make a large drawing of one cell and label the following parts: cell wall, cell membrane, cytoplasm, and nucleus.
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O-LEVEL ATP NOTES
13
Unit-2: Diffusion and Osmosis
Observing the effect of surface area on rate of diffusion Surface area impact the rate of diffusion very significantly; in order to observe the effect we will use starch agar instead of living specimen.
Use a large block of starch agar at least 3 cm thick. Using a ruler and a sharp knife, measure and cut four cubes from the jelly with sides of 3.0 cm, 2.0 cm, 1.0 cm and 0.5 cm. Place the cubes into a beaker of methylene blue dye or potassium permanganate solution. After 15 minutes, remove the cubes with forceps and place them on to a white tile. Cut each of the cubes in half and measure the depth to which the dye has diffused. Calculate the surface area and volume of each cube and construct a table of your data. Remember to state the units in the heading for each column.
Results and Discussion Formula to calculate surface area = 6 * (L)2 For example the surface area for each cube is: Smallest cube = 1.50 Smaller cube = 6 Medium cube = 24 Larger cube
= 54
By comparing surface area to the volume ratio we can conclude that a smaller cube will be having a greater rate of diffusion; though its surface area is smaller. Now assume that each cube was representing a small living organism with each having different body size. We can conclude that the organism with smaller body size like unicellular can simply rely on diffusion for their oxygen needs but for larger organisms diffusion can’t work as rate of diffusion would be lower as compared to their need so they need a welldeveloped system like respiratory system.
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O-LEVEL ATP NOTES
14
Unit-2: Diffusion and Osmosis
Practice Questions related to Cells Sample Question (1)
Fig. 1.1 (i)
Mark the following on Fig. 1.1: cell wall, cell membrane, sap vacuole, nucleus, chloroplast. [5]
(ii)
What role do chloroplasts perform during photosynthesis?
[2] (iii)
Which structure enables a plant cell to retain its shape better than an animal cell? [1]
(iv)
Name two types of plant tissue. [2] [Total: 10]
Sample Question (2) (i)
Draw a labelled diagram of an animal cell in the space below:
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O-LEVEL ATP NOTES
(ii)
15
Unit-2: Diffusion and Osmosis
If the diameter across an animal cell measures 0.01 mm, calculate the magnification of your diagram.
[4] (iii)
Compare animal cells with plant cells in Table 2.1: Table 2.1 Feature / Characteristic Cell wall Vacuole Mode of nutrition Chloroplasts Stored food
Animal cell
Plant cell
[5] [Total: 14] Sample Question (3) (i)
A student observed red blood cells, muscle cells, and root hair cells under a microscope. List two features for each type of cell that could help him to identify the cells.
[6] (ii)
How are ciliated cells adapted for filtering air entering the lungs?
[2] (iii)
Name two cells that require a large surface area to perform their function. [2] [Total: 10]
Sample Question (4) (i)
Use arrows to illustrate how specialized cells combine into complex organ systems.
[4]
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O-LEVEL ATP NOTES
(ii)
16
Unit-2: Diffusion and Osmosis
Why is cell specialization observed in multicellular organisms?
[2] [Total: 6] Sample Question (5) The maximum size of most living cells is determined by the ratio of their surface area to their volume. As cells increase in size, their volume increases proportionally more than their surface area, thus limiting the ability of the surface area to supply the cell with all the nutrients the cell needs. A student investigated the relationship between the volume and surface area in model cells made of red-coloured agar jelly and the absorption of a liquid by those model cells using the method outlined below. The student was provided with a piece of red-coloured agar, labelled A1 and a solution, labelled A2. These are the instructions that the student used.
Using a sharp knife a scalpel, cut the agar block into three cubes, each approximately 1cm × 1cm × 1cm. Place one of these cubes into a large test-tube. Cut one of the remaining cubes into 8 blocks so that each block is approximately 0.5cm × 0.5cm × 0.5cm. Put all 8 blocks into another large test-tube. Cut the remaining cube into two equal pieces. Put these two equal pieces into a third large testtube. The agar blocks in the test-tubes are the model cells. The student added solution A2 to each test-tube knowing that, as this solution diffused into the agar, the agar would change colour from red to pale orange. The student measured the time taken for each of the model cells in each of the test-tubes to change colour completely after A2 was added. This is what the student recorded.
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O-LEVEL ATP NOTES
(a)
17
Unit-2: Diffusion and Osmosis
Prepare a table in the space below in which to record: ď‚—
the total surface area of the blocks in each test-tube,
ď‚—
the time taken for the colour change.
Transfer the information the student recorded into your table. Carry out any calculations needed and complete the table.
[5] (b)
The student carried out a similar experiment and went on to compare the surface area to volume ratio with the time taken for the blocks to lose their red colour. The results are shown in Table 1.1 Table 1.1
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surface area volume
time/sec
1.5
120
2
105
3
84
4
60
6
30
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O-LEVEL ATP NOTES
18
Unit-2: Diffusion and Osmosis
(i)
Construct a graph of these results on the grid below.
(ii)
State the relationship between the surface area to volume ratio of the blocks and the time taken for substances to diffuse into them that is shown by the graph you have drawn.
[5]
[1] (c)
Suggest two possible sources of experimental error, other than variations in temperature, which may have affected the results of the investigation.
[2] (d)
Describe how the structure and function of a living animal cell differs from the model cells in the movement of substances into the cell.
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