Classification of Bacteria of Medical Importance

Question 1

organisms that grow best with higher CO2 concentration (5-10%) and approximately 15% O2.

Answer 1

Capnophilic

Question 2

Base-loving; pH 8.0 –11.

Answer 2

Alkaliphils

Question 3

a Criteria for Genetic Relatedness that the base composition of a single species theoretically is an invariable, fixed property and thus affords a measure of species relatedness.

Answer 3

Chemical composition of the DNA

Question 4

leads to rupture of cell (Plasmoptysis)

Answer 4

Hypotonic solution

Question 5

Acid-loving; grows best at a pH range of 0.1

Answer 5

Acidophils

Question 6

what happens when there is change in pH

Answer 6

• denaturation of enzymes and other proteins
• can interfere with pumping of ions at the cell membrane.

Question 7

particularly useful for determining cell size and arrangement cell size and arrangement

Answer 7

• Negative staining

Question 8

strict anaerobe grows in the absence of O2

Answer 8

Obligate Anaerobe

Question 9

strictly aerobic

Answer 9

Obligate Aerobe

Question 10

a type of pH requirement with a pH of 5.5 –7.0

Answer 10

Neutrophils

Question 11

• grows at a temperature below 10oC (0-25oC)
• “Cold-loving”

Answer 11

Psychrophil/ Psychrophilic

Question 12

basically anaerobic but are able to survive in the presence of small amounts of O2.

Answer 12

Facultative aerobe

Question 13

energy and carbon source of Photoautotroph

Answer 13

• Energy source: Sunlight
• Carbon source: CO2

Question 14

an extra chromosomal DNA molecules separate from the chromosomal DNA which is capable of replicating independently of chromosomal DNA.

Answer 14

• Plasmid

Question 15

requires high concentration of salt (salt acts as osmotic force that prevents the rupture of the cell’s unusually fragile wall.)

Answer 15

Halophilic organism

Question 16

Strictest criterion in the Criteria for Genetic Relatedness

Answer 16

DNA Homology

Question 17

leads to shrinkage of cell (Plasmolysis)

Answer 17

Hypertonic solution

Question 18

size range of most bacteria

Answer 18

0.4 -2.0 μm

Question 19

Most commonly used stain

Answer 19

Grams’s staining Technique & AFB staining Technique

Question 20

requires less than 1 atmosphere of O2, usually about 0.2 atmosphere (5-10% O2)

Answer 20

Microaerophilic

Question 21

basically aerobic but grows also in the absence of O2

Answer 21

Facultative anaerobe

Question 22

• also known as “Lithotroph” or “Lithoautotroph”
• depends totally on “inorganic” (non-living) matter for growth

Answer 22

Autotroph / Autotrophic

Question 23

the ultimate indicator of genetic relatedness; a comparison of DNA sequences

Answer 23

Natural / Phylogenetic

Question 24

The amount of 2 DNA components, Guanine and Cytosine are measured, yielding a value called

Answer 24

G+C contents

Question 25

• grows at 45oC and above (450C –850C)
• “heat-loving”

Answer 25

Thermophil/ thermophilic

Question 26

• are unable to use O2 as an electron acceptor

Answer 26

Anaerobic

Question 27

• uses O2 as a terminal electron acceptor and grows well at Room air
• requires air containing 21% O2 & .03% CO2

Answer 27

Aerobic

Question 28

The ability of an organism to grow at various temperatures, in the presence of oxygen and other gases, at various pH levels, or in the presence of other ions and salts such as NaCl.

Answer 28

• Environmental requirement

Question 29

energy and carbon source of
Chemoautotroph

Answer 29

• Energy source: Simple Inorganic
  compound (Iron, Sulfur, Hydrogen)
• Carbon source: CO2

Question 30

energy and carbon source of Autotroph / Autotrophic

Answer 30

Energy source: Non-living environment (Nitrates, sulfates, phosphates)

Carbon source: Carbon dioxide (CO2)

Question 31

pH range that bacteria

Answer 31

6.5 –7.5(6-8)

Question 32

a stain used to reveal negatively charged bacterial capsules

Answer 32

• Staining

Question 33

best indicator of genetic relatedness.

Answer 33

degree of homology

Question 34

usually used in conjunction with microscopic morphology as part of the process of bacterial identification

Answer 34

• Staining

Question 35

• grows at 37oC (250C-450 C)
• Most if not all pathogenic bacteria

Answer 35

Mesophil/ Mesophilic

Question 36

Easiest approach in the Criteria for Genetic Relatedness

Answer 36

Comparison of the size of the entire chromosome

Question 37

Measures similarities in the sequential order in which molecular building blocks of DNA are arranged

Answer 37

DNA Homology

Question 38

are easiest to analyze for DNA similarities, they have only one chromosome

Answer 38

• Prokaryotic cells