15. Year (entry) A* A B C D E U 2009 AQA AS Biology (26361) 17.2 34.0 52.2 68.2 81.1 100.0 National AS Biology 18.6 35.5 53.3 69.3 82.6 100.0 2010 AQA AS Biology (32672) 18.9 36.4 54.7 71.0 83.9 100.0 National AS Biology (83408) 18.7 36.4 54.3 70.3 83.6 100.0 AQA A level Biology (23295) 8.8 29.4 52.5 73.1 88.2 97.2 100.0 National A Level Biology (55485) 8.0 28.5 51.7 72.4 87.6 96.8 100.0
16. A* A B C D E U A level Human 2009 13.1 34.4 57.0 77.3 92.9 100 2010 3.0 11.8 31.2 54.6 77.5 93.4 100 A level Biology 2010 8.8 29.4 52.5 72.1 88.2 97.2 100 National A level 2010 8.0 28.5 51.7 72.4 87.6 96.8 100 AS Human 2009 7.5 18.3 35.6 53.9 69.1 100 2010 8.8 21.0 40.7 57.0 73.1 100
36. To help you process your data, the time required for each stage of the cell cycle can be calculated using the formula: Number of minutes = number of cells in stage x 720 to complete a stage total number of cells counted Stage Number of cells Time in each stage Interphase 177 504 Prophase 4 7.2 Metaphase 7 14.4 Anaphase 1 2880 Telophase 63 180
37. Stage of mitosis Number of cells in stage of mitosis Percentage of cells in stage of mitosis Time to complete stage of mitosis / minutes Prophase 108 0.74 72.9 Metaphase 16 5 21.6 Anaphase 8 10 13.5 Telophase 28 2.86 3.85
38. A scientist studying onion root tips found that the time taken for mitosis was about 80 minutes . She recognised that the proportion of 80 minutes that a stage of mitosis took to complete could be found from the percentage of cells in that stage of mitosis. She used this to calculate the time in minutes for each stage of mitosis. Use the scientist’s method to complete the table. Stage of mitosis Number of cells in stage of mitosis Percentage of cells in stage of mitosis Time to complete stage of mitosis / minutes Prophase 108 112.5 54 Metaphase 16 10 8 Anaphase 8 5 4 Telophase 28 17.5 14
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41. Table 1 Temperature ( o C) Test 1 Test 2 Test 3 Average (m) Colour Time (m) Colour Time (m) Colour Time (m) 20 Blue 3.20 Blue 1.55 Blue 2.50 2.41 30 Blue 2.53 Blue 3.06 Blue 4.09 3.22 40 Blue 1.26 Blue 2.35 Blue 2.20 1.93 50 Blue 1.46 Blue 1.02 Blue 0.45 0.97 60 Blue 0.60 Blue 1.25 Blue 2.26 1.37
42. Table 2 ‘ Effect of temperature on time taken to change colour’ Time (s) Average (s) Temp o C Tube 1 Tube 2 Tube 3 20 193 159 171 174 30 128 131 176 145 40 91 82 117 97 50 97 103 120 107 60 260 317 302 293
43. Table 3 Test tube Temperature of water bath Time taken to turn blue Repeat time taken to turn blue Average 1 20 o C 7 minutes 15 seconds 7 minutes 11 seconds 7 minutes 13 seconds 2 30 o C 2 minutes 1 minute 45 seconds 1 minute 52.5 seconds 3 40 o C 36 seconds 47 seconds 41.5 seconds 4 50 o C 34 seconds 31 seconds 32.5 seconds 5 60 o C 8 minutes 57 seconds 9 minutes 33 seconds 9 minutes 15 seconds
74. The table shows the respiratory minute volume (volume of air inspired per minute) of three healthy young men subjected individually to a progressive decrease in the oxygen content of their inspired air. Carbon dioxide content was held at a constant level. The RMV was calculated for each minute for 10 minutes as shown. Time / minutes 1 2 3 4 5 6 7 8 9 10 Oxygen content of inspired air / % 21 18 16 14 12 10 8 6 5 4 RMV / dm 3 per minute Man A 6.6 6.8 6.9 6.9 7.2 8.6 12.9 18.2 21.0 25.5 Man B 7.4 7.4 7.3 7.3 7.3 7.4 11.5 18.0 19.7 24.4 Man C 7.0 6.8 6.8 6.8 7.1 8.0 11.6 17.8 19.3 25.1
