Microlab Midterm - Exercise #2
How do you distinguish true motility from Brownian movement or motion of the fluid?
- Brownian: Vibration - True motility: point a to point b
Why are microorganisms hard to see in wet preparations?
Because they are transparent
What is the wet mount technique?
Draw circle Drop the slide on water
Which infusion had the most bacteria and why?
Hay infusion; hay is a nutrient and a microorganism
What is Brownian movement?
Not actual movement, vibration of the cells
Why is petroleum jelly used in the hanging-drop procedure?
Prevents the evaporation of suspended fluid
A wet mount may be used for quick examination of fecal samples. Is this most useful for identifying protozoa or bacteria parasites?
Protozoa - Bacteria parasites are clear and too small to observe under a microscope
What are aseptic techniques used for?
Removal of unwanted microorganisms
What is flaming used for?
Sterilization
What is a microbiome?
The environment of a microorganism
Why isn't the oil immersion lens used in the hanging-drop procedure?
Too much light refraction
What is an inoculating loop used for?
Transfer of bacteria
What is true movement?
When a cell moves from point a to point b
What is the advantage of the hanging-drop procedure over the wet mount?
a hanging drop will allow you to easily observe motility and larger microbes
