Bacterial(细菌)growth Time Number of Cells 70 0 minutes 1 =20 60 20 2 =21 40 4 =22 50 60 8 =23 80 16 -24 40 100 32 =25 30 120(=2 hours) 64 =26 =29 20 3 hours 512 G=rN 4 hours 4,096 =212 10 8 hours 16,777,216 =224 20406080100120140 12 hours 68,719,476,736=236 Time(min) Figure 35.3A 12 12 Figure 35.3A Bacterial (细菌) growth