micro exam 1 LC

Select the characteristics of a microbe. Choose all that apply.

1. Too small to be seen with the unaided eye

2. Composed of cells

3. Primary role is to cause illness

4. Found almost everywhere

1 and 4

Did Pasteur’s work support the theory of biogenesis or the theory of spontaneous generation?

1. Biogenesis

2. Spontaneous generation

3. Both

4. Neither

1

You discovered a unicellular organism that lacks a nucleus. The cell wall of this organism was found to contain peptidoglycan. To which domain does this organism belong?

1. Domain Eukarya

2. Domain Bacteria

3. Domain Archaea

2

Why are viruses not included in the three domain system of classification?

1. Viruses do not have plasma membranes

2. Viruses are not alive

3. Viruses do not have cells

4. Viruses do not have nuclei

2 and 3

A bacterial cell is measured to be 4000 nm in length. Express this measurement in micrometers.

4

What is the total magnification with a 10X ocular lens when using the high-dry objective (40X)?

1. 10X

2. 40X

3. 50X

4. 100X

5. 400X

6. 4000X

400X

Why is immersion oil necessary when using the 100X objective (1000X total magnification), but not when using the lower power objectives?

1. The 100X objective lens is larger than the lower power objective lenses

2. The 100X objective lens is smaller than the lower power objective lenses

3. The 100X objective lens uses a shorter wavelength of light

4. The 100X objective uses a longer wavelength of light

2

What type of microscopy would you use if you wanted a high resolution view of structures on the surface of a paramecium (a unicellular protozoan)?

1. Brightfield

2. Darkfield

3. Phase-contrast

4. Confocal

5. Transmission electron microscopy (TEM)

6. Scanning electron microscopy (SEM)

7. Atomic force

6

What type of microscopy would you use if you wanted to study the structure of a bacterial biofilm on a glass slide?

1. Brightfield

2. Darkfield

3. Phase-contrast

4. Confocal

5. Scanning acoustic microscopy

6. Atomic force

5

Select the major features of a prokaryotic cell.

1. Lack membrane bound organelles

2. DNA found in the nucleus

3. DNA associated with histones

4. Chemically simple cell walls

5. Divide by binary fission

6. Divide by mitosis

7. DNA is typically a single, circular chromosome

1, 5 and 7

This is a Gram stain from a sputum (mucus) sample of a patient with a respiratory infection.

Are the bacterial cells in this image Gram positive or Gram negative?

Gram positive

This is a Gram stain from a sputum (mucus) sample of a patient with a respiratory infection.

What is the cell shape and arrangement of the bacterial cells in this image?

1. Diplobacilli

2. Streptobacilli

3. Staphylococci

4. Cocci in tetrads

5. Streptococci

6. Individual spirochetes

C

Which two structures are used to identify the serovar of Escherichia coli O157:H7?

(Hint: E. coli is a Gram negative bacillus)

1. Peptidoglycan

2. Lipopolysaccharide

3. Teichoic acid

4. Flagella

5. Pili

6. Axial filament

7. Plasma membrane

2 and 4

What type of bacterial cell wall is depicted in this image?

1. Gram positive

2. Gram negative

3. Acid-fast

4. Encapsulated

2

Why should bacterial cells not be placed in a solution of pure water?

1. The cells will lose water, causing plasmolysis

2. The cells will lose water, causing them to burst

3. The cells will take on water, causing them to burst

4. The cells will take on water, causing plasmolysis

3

Which of the following statements about bacterial endospores is TRUE?

1. Endospores are used for reproduction.

2. A single vegetative cell can produce many endospores.

3. Endospores allow a cell to survive environmental changes.

4. A vegetative cell produces one endospore and keeps growing.

5. Endospores are easily stained using a Gram stain.

3

Select the major features of a eukaryotic cell.

1. Lack membrane bound organelles

2. DNA found in the nucleus

3. DNA associated with histones

4. Cell walls usually contain peptidoglycan

5. Chemically simple cell walls

6. Divide by binary fission

7. Divide by mitosis

8. DNA is typically a single, circular chromosome

2, 3, 5 and 7

Which of the following may be found in eukaryotic cells, but not in prokaryotic cells?

(Select all that apply.)

1. Cell wall

2. Cytoplasm

3. Cytoplasmic membrane

4. DNA

5. Endoplasmic reticulum

6. Flagella

7. Golgi body

8. Mitochondria

9. Nucleoid

10. Nucleus

11. Peptidoglycan

12. Ribosomes

13. Fimbriae

5, 7, 8,10

What is unusual about the ribosomes found in the chloroplasts and mitochondria?

1. They are larger than eukaryotic ribosomes

2. They are smaller than eukaryotic ribosomes

3. They are similar to prokaryotic ribosomes

4. Nothing. They are the same as other ribosomes in the eukarytotic cell.

2 and 3

True or false?

Fungal spores and bacterial endospores have the same structure and function.

False

Are viruses living or non-living?

1. Living

2. Non-living

2

Why can viruses not be cultivated in plain culture media like bacteria?

1. Normal culture media does not contain enough protein for viruses to replicate.

2. Normal culture media does not contain enough ATP for viruses to replicate.

3. Viruses require host cells to be able to replicate.

4. Viruses are too small to be isolated in the laboratory.

3

Which of the following is NOT part of a bacteriophage replication cycle?

1. Virion binds to a host cell surface protein that provides an important host function

2. The virion injects its genome into the host cell

3. The capsid of the virion enters the host cytoplasm

4. The viral genome directs the host ribosomes to synthesize viral components

3

This is Epulopiscium fishelsoni, an organsism found in the gut of the Red Sea surgeon fish. It is 80 µm x 600 µm. Based only on this information, how would you classify this organism?

Eukaryote

This is Mycoplasma pneumoniae. It is 0.1-0.25 µm. How would you classify it?

Prokaryote