1. How does increased magnification affect the field of vision? 2. Why it is desirable that microscope objectives be parfocal? 3. Which objective focuses closest to the slide when it is in focus? Critical Thinking 4. Assume the diameter of the field of vision in your microscope is 2 mm under low power, If one Bacillus cell measures 2 um long, how many Bacillus cells could fit end-to-end across the field? How many 10-um yeast cells could fit across the field? 5. What would occur if water were accidentally used in place of immersion oil? Clinical Application 6. Assume you are looking for microorganisms in a tissue sample from a lung biopsy. The microbes become apparent when you switch to 1000x, What type of microbe is most likely?