BIOL 3150 – Microbiology Final Exam
and All Correct Answers.
What is Microbiology? - Answer The study of microorganisms
Robert Hooke - Answer Microscope 1655
Antoni van Leeuwenhoek - Answer Discovered bacteria with the microscope --> 1676
Condenser lens: - Answer Focuses light on specimen
Objective Lens: - Answer Magnifies specimen
Ocular lens - Answer Further magnifies image (10X)
How do you determine the total magnification? - Answer Multiply objective by ocular to find
total magnification
Microscopy Field of view - Answer As magnification increases the FOV decreases
What happens to the depth of field as the magnification increases? - Answer As mag
increases depth of field decreases
Light microscopes: - Answer Used to look at intact cells under relatively low magnification
Resolution - Answer The ability to distinguish two adjacent objects as separate and distinct
- determined by the wavelength of light used and the numerical aperture.
- R = 0.61lambda/NA
Resolving Power: - Answer How close can two things be, and still be seen as two separate
entities
- Typical = 0.2 micrometres
,Oil Immersion lens - Answer The oil has a high refractive index
Makes images sharper
Types of light microscopy (4) - Answer Bright field
Phase contrast
Dark field
Fluorescence
Improving Contrast in Light Microscopy - Answer Staining is an easy way to improve contrast
Simple versus Differential Stains - Answer Simple Stain: One dye used to visualise a
microorganism on a slide
Differential Stain: Two dyes used to distinguish microorganisms
Louis Pasteur - Answer A French chemist, this man discovered that heat could kill bacteria
that otherwise spoiled liquids including milk, wine, and beer.
- Dust could not get in due to swan neck
- Medium did not contaminate until mixture
Robert Koch - Answer Father of modern bacteriology
The 4 Postulates - Answer 1.) Pathogenicity - Suspected pathogen must be present in all
cases of the disease and absent from healthy animals
a.) Isolate a blood sample from organism
2.) Suspected pathogen must be grown in pure culture
b.) Pure culture is needed to have more of the sample of interest and specificity to a specific
pathogen
3.) Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal
c.) Take a healthy new mouse and inoculate it (expose to bacteria)
4.) The suspected pathogen must be reisolated and shown to be the same as the original
, d.) The new diseased animal must be used to take a sample to determine if it is the same
causative agent (pathogen)
Risk Group Classification - Answer 1.) Pathogenicity: How likely is it that this organism will
cause the disease
2.) What is the mode of transmission/host range: How is it spread? (sneezing, blood contact,
human-human) and to who or what?
3.) Availability of effective preventative measures
4.)Availability of effective treatment
Properties of all cells (4) - Answer 1.) Structure
2.) Metabolism
3.) Growth
4.) Evolution
Properties of some cells (4) - Answer 1.) Differentiation
2.) Communication
3.) Motility
4.) Horizontal gene transfer
Microbial Eukarya: (3) - Answer Protists(e.g.Amoeba)
Slime moulds (e.g.dictyostelium)
Fungi (e.g.yeasts and mould)
Archaea Cell Shape (4) - Answer Microscopically Archaea can appear as
- Cocci
- Bacilli
- Triangles
- Squares
Typically less that 1 micrometre in length
and All Correct Answers.
What is Microbiology? - Answer The study of microorganisms
Robert Hooke - Answer Microscope 1655
Antoni van Leeuwenhoek - Answer Discovered bacteria with the microscope --> 1676
Condenser lens: - Answer Focuses light on specimen
Objective Lens: - Answer Magnifies specimen
Ocular lens - Answer Further magnifies image (10X)
How do you determine the total magnification? - Answer Multiply objective by ocular to find
total magnification
Microscopy Field of view - Answer As magnification increases the FOV decreases
What happens to the depth of field as the magnification increases? - Answer As mag
increases depth of field decreases
Light microscopes: - Answer Used to look at intact cells under relatively low magnification
Resolution - Answer The ability to distinguish two adjacent objects as separate and distinct
- determined by the wavelength of light used and the numerical aperture.
- R = 0.61lambda/NA
Resolving Power: - Answer How close can two things be, and still be seen as two separate
entities
- Typical = 0.2 micrometres
,Oil Immersion lens - Answer The oil has a high refractive index
Makes images sharper
Types of light microscopy (4) - Answer Bright field
Phase contrast
Dark field
Fluorescence
Improving Contrast in Light Microscopy - Answer Staining is an easy way to improve contrast
Simple versus Differential Stains - Answer Simple Stain: One dye used to visualise a
microorganism on a slide
Differential Stain: Two dyes used to distinguish microorganisms
Louis Pasteur - Answer A French chemist, this man discovered that heat could kill bacteria
that otherwise spoiled liquids including milk, wine, and beer.
- Dust could not get in due to swan neck
- Medium did not contaminate until mixture
Robert Koch - Answer Father of modern bacteriology
The 4 Postulates - Answer 1.) Pathogenicity - Suspected pathogen must be present in all
cases of the disease and absent from healthy animals
a.) Isolate a blood sample from organism
2.) Suspected pathogen must be grown in pure culture
b.) Pure culture is needed to have more of the sample of interest and specificity to a specific
pathogen
3.) Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal
c.) Take a healthy new mouse and inoculate it (expose to bacteria)
4.) The suspected pathogen must be reisolated and shown to be the same as the original
, d.) The new diseased animal must be used to take a sample to determine if it is the same
causative agent (pathogen)
Risk Group Classification - Answer 1.) Pathogenicity: How likely is it that this organism will
cause the disease
2.) What is the mode of transmission/host range: How is it spread? (sneezing, blood contact,
human-human) and to who or what?
3.) Availability of effective preventative measures
4.)Availability of effective treatment
Properties of all cells (4) - Answer 1.) Structure
2.) Metabolism
3.) Growth
4.) Evolution
Properties of some cells (4) - Answer 1.) Differentiation
2.) Communication
3.) Motility
4.) Horizontal gene transfer
Microbial Eukarya: (3) - Answer Protists(e.g.Amoeba)
Slime moulds (e.g.dictyostelium)
Fungi (e.g.yeasts and mould)
Archaea Cell Shape (4) - Answer Microscopically Archaea can appear as
- Cocci
- Bacilli
- Triangles
- Squares
Typically less that 1 micrometre in length
