Part - I

a) Briefly explain the principles of microscopy

b) What is the difference between magnification and resolution

c) Compare and contrast bright-field and dark-field microscopes

d) Explain how phase-contrast and fluorescence microscopes work.

Part - II

a) Explain the importance of staining techniques in microbiology

b) Explain the principle and describe the procedure (giving rationale for each step) of:

i. Gram stain

ii. Acid-fast stain

Part - III

Explain in details any five (physical or chemical) ways of controlling microbial growth in the food industry.