Page 03 3. The figure shows how a scientist used serial dilution followed by plating to check the number of bacteria in a stock culture. 0∙1 cm3 transferred to agar plate followed by incubation for 2 days 9∙0 cm3 119 colonies 1∙0 cm3 1∙0 cm3 1∙0 cm3 1∙0 cm3 Bacterial stock How many bacteria were there in 1 cm3 of the original bacterial stock? A 1·19 × 105 B 1·19 × 106 C 1·19 × 107 D 1·19 × 108 4. Place the following events for a sodium potassium pump into the correct sequence. 1 Phosphorylation 2 Potassium ions released into cell 3 Transporter protein has high affinity for sodium ions inside the cell 4 Dephosphorylation A 2, 1, 4, 3 B 3, 4, 2, 1 C 2, 1, 3, 4 D 3, 1, 4, 2 [Turn over