8. What are the diagnostic criteria for type II diabetes? ( 9. Explain why glycated haemoglobin (HbA1C) is a suitable index for long term hyperglycaemia. (5 marks) 10. Briefly explain how insulin and glucagon work in concert to regulate blood glucose.(5 marks)

5. Explain briefly why the 100X objective lens of the light microscope is immersed in oil. (5 marks) 6. Describe why the Gram stain can differentiate between Gram positive and Gram-negative cells? (5 marks) 7. Name 6 different colony characteristics that can be used to distinguish microorganisms from one another. (5 marks)

1. Why is it necessary to maintain aseptic conditions in microbiology? 2. Explain why the following steps are necessary during sub culturing: dFlaming the inoculating loop before and after each inoculation (= b. Cooling the inoculating loop before touching the inoculum/culture ( Flaming the neck of tubes/bottles after capping and before re-capping ( Can pure culture be prepared directly from a mixed culture? Explain your answer. 4. You have been asked to determine the bacterial count in a sample of water. The-number of CFU from 1 ml of a 106 dilution was 43 and 49 on duplicate agar plates.per ml of the original sample of water? (5What is the total number of microorganisms-marks)

In an experiment the transport of the neurotransmitter serotonin into cultured mammalian cells was measured. Batches of cells were incubated with solutions of different concentrations of radio labelled [3H]-serotonin for a defined time, cells were then separated from the incubation buffer, and serotonin accumulated into the cells was determined by scintillation counting. The rate of transport is given as dpm/min* (see table below). In order to elucidate the transport mechanism, the experiment was conducted under two different conditions, i.e., in condition A normal transport buffer was used, and in condition B the transport buffer did not contain any Na* ions.[Notes: * dpm/min means disintegrations per minute and is a measure of the intensity of-radioactivity of a radio-labelled compound; it is directly related to the rate of transport for this compound] 11. Draw a graph (by using Excel or similar), plotting the serotonin concentration against the-transport rate under both conditions. (5 Marks). 12. What transport rates for each condition would you expect if the experiment was repeated-using 12μM [³H] serotonin? Add your estimate into the table above. (5 Marks). 13. Examine the plot obtained for condition A; what can you conclude with regards to-whether or not the transport of serotonin into these cells requires a protein? Explain your conclusion. (10 Marks). 14. Compare the plots of the transport rates for both conditions. What is most likely mechanism of transport for serotonin into these cells? Explain your interpretation. (10Marks).