Bacteriology 1

Question 1

What is a bacterium?

Answer 1

Single-celled microorganism that belongs to the prokaryote kingdom.

Question 2

T/F: Bacteria have a nucleus.

Answer 2

False, no nucleus or membrane bound organelles.

Question 3

How does cell division occur in prokaryotes?

Answer 3

Binary fission

Question 4

T/F: A prokaryotic chromosome is circular and contains no histones.

Answer 4

True

Question 5

How do bacteria grow?

Answer 5

They grow in aerobic, anaerobic or microaerophilic conditions, and some require cells to grow.

Question 6

Name a few types of bacterial morphology/ shapes.

Answer 6

Cocci (spherical), Bacillus (rod-shaped), helical/ spiral shaped, curved/ comma shaped.

Question 7

In gram positive bacteria, what compound is contained in the cell wall?

Answer 7

Lipoteichoic acid

Question 8

In gram negative bacteria, what compound is contained in the outer membrane?

Answer 8

Lipopolysaccharide (LPS)

Question 9

In mycobacteria, what unique component is located in the cell wall?

Answer 9

Mycolic acid

Question 10

T/F: In gram positive, gram negative, and mycobacteria there is peptidoglycan in the cell wall.

Answer 10

True

Question 11

In gram positive bacteria, what is Lipoteichoic acid used for?

Answer 11

Antigenicity

Question 12

T/F LPS is an endotoxin found in gram negative bacteria and is antigenic.

Answer 12

True

Question 13

What color do Gram positive bacteria stain?

Answer 13

Purple

Positive= Purple

Question 14

What color do Gram negative bacteria stain?

Answer 14

Pink

Negative has an “n”, Pink has an “n”

Question 15

What is the purpose of the alcohol wash when staining?

Answer 15

Decolorization

Question 16

Acid fast staining is due to the presence of what?

Answer 16

Mycolic acid

Question 17

Acid fast positive organisms are said to be stained pink. What is the name of the primary stain used?

Answer 17

Carbol fuchsin

Question 18

When gram staining, what is the name of the counterstain used?

Answer 18

Safranin

Question 19

When acid fast staining, what is the name of the counterstain used?

Answer 19

Methylene Blue

Question 20

Why do acid fast negative bacteria get stained blue?

Answer 20

They get decolorized due to the absence of mycolic acid.

Question 21

What are flagella used for?

Answer 21

Locomotion or motility.

Question 22

Describe the structure of Amphitrichous flagella.

Answer 22

2 total, one on either side.

Question 23

Where are the flagella located on Peritrichous?

Answer 23

Numerous all the way around

Question 24

What are Pili/ fimbriae?

Answer 24

Small thread-like structures on bacterial surface.

Question 25

What do Pili do?

Answer 25

Facilitate adherence to the host tissue through specific receptors.

Question 26

What is a capsule?

Answer 26

Thick polysaccharide layer outside of the cell wall.

Question 27

What is a capsule used for?

Answer 27

Sticking cells together, as a food reserve, as protection against desiccation and chemicals, helps bacteria to evade phagocytosis.

Question 28

What is a survival mechanism for some gram positive bacteria?

Answer 28

Endospores

Question 29

T/F: Spores are highly resistant dormant form of bacteria.

Answer 29

True

Question 30

When are endospores produced?

Answer 30

When bacteria are exposed to adverse conditions & when essential nutrients are depleted.

Question 31

Name the different phases of bacterial growth.

Answer 31

Lag phase, log phase, stationary phase, death phase.

Question 32

How can bacterial growth be measured by?

Answer 32

Colony counting, turbidimetry, flow cytometer, hemocytometer chamber.

Question 33

What is another name for the log phase?

Answer 33

Exponential phase

Question 34

What kinds of bacteria require oxygen for growth?

Answer 34

Aerobic, microaerophilic, capnophilic

Question 35

What kinds of bacteria do NOT require oxygen for growth?

Answer 35

Obligate anaerobe, aerotolerant anaerobe

Question 36

What kinds of bacteria do not require oxygen, but can utilize it for growth?

Answer 36

Facultative anaerobe