Question 1

Which of the following is NOT an enteric?

Accepted Answer

B

Question 2

You have isolated a bacterium that grows in a medium containing only inorganic nutrients. Ammonia is oxidized to a nitrate ion. This bacterium is

Accepted Answer

The fact that the bacterium is growing in a medium containing only inorganic nutrients and is oxidizing ammonia to nitrate suggests that it is a chemoautotroph, meaning it is using inorganic compounds as a source of both energy and carbon.

Question 3

Which one of the following bacteria does NOT belong with the others?

Accepted Answer

Bacillus, Staphylococcus, Streptococcus, and Lactobacillus are all Gram-positive bacteria, while Escherichia is a Gram-negative bacteria.

Question 4

Escherichia coli belongs to the

Accepted Answer

Escherichia coli belongs to the proteobacteria, which is a diverse group of gram-negative bacteria.

Question 5

You have isolated a bacterium that grows in a medium containing an organic substrate and nitrate in the absence of oxygen. The nitrate is reduced to nitrogen gas. You can be sure that this bacterium is

Accepted Answer

The fact that the bacterium is able to grow using an organic substrate and nitrate in the absence of oxygen suggests that it is using anaerobic respiration. The reduction of nitrate to nitrogen gas is a common feature of anaerobic respiration. Therefore, option E is the best choice. None of the other options provide information that is relevant to the characteristics of this bacterium.

Question 6

Which of the following are found primarily in the intestines of humans?

Accepted Answer

Facultatively anaerobic gram-negative rods are commonly found in the intestines of humans, where they play a role in digestion and nutrient absorption. Gram-negative aerobic rods and cocci can also be found in the intestines, but are not the primary bacteria present. Endospore-forming rods and gram-positive cocci are not typically found in high numbers in the intestines. Aerobic, helical bacteria may also be present in the intestines, but again are not the primary bacteria present.

Question 7

Which of the following is NOT a characteristic of Neisseria?

Accepted Answer

The answer of Which of the following is NOT a...

Question 8

Staphylococcus and Streptococcus can be easily differentiated in a laboratory by which one of the following?

Accepted Answer

Staphylococcus species are able to grow in high salt concentrations, while Streptococcus species cannot. Therefore, this is an easy way to differentiate the two types of bacteria in a laboratory.

Question 9

Which of the following bacteria is gram-positive?

Accepted Answer

Streptococcus is a gram-positive bacteria, whereas Bacteroides and Pseudomonas are gram-negative, Salmonella is gram-negative facultative anaerobe, and Rickettsia is a gram-negative obligate intracellular bacteria.

Question 10

Which of the following do you expect to be MOST resistant to high temperatures?

Accepted Answer

Bacillus subtilis is a thermophilic bacterium, meaning it is adapted to grow at high temperatures and would therefore be the most resistant to high temperatures compared to the other options given.

Question 11

Which of the following genera is an anaerobic gram-negative rod?

Accepted Answer

Bacteroides is an anaerobic gram-negative rod. The other options are aerobic or facultative anaerobic gram-negative rods.

Question 12

Figure 11.1  What is group ʺc.ʺ in the key shown in Figure 11.1?

Accepted Answer

The answer of Figure 11.1  What is group ʺc.ʺ...

Question 13

Which of the following bacteria is gram-negative?

Accepted Answer

Treponema is a gram-negative spiral-shaped bacteria. Bacillus, Corynebacterium, and Staphylococcus are gram-positive while Mycobacterium is an acid-fast bacteria.

Question 14

Which of the following is NOT a characteristic inherent of the non-endospore-forming gram-positive rods?

Accepted Answer

The answer of Which of the following is NOT a...

Question 15

Which of the following form conidiospores?

Accepted Answer

The answer of Which of the following form conidiospores?
...

Question 16

Which of the following lacks a cell wall?

Accepted Answer

Mycoplasma species lack a true cell wall, making them unique among bacteria.

Question 17

Requirements for X and V factors are used to identify

Accepted Answer

The answer of Requirements for X and V factors are...

Question 18

Which of the following is NOT a characteristic of spirochetes?

Accepted Answer

Spirochetes are characterized by their helical shape and possession of an axial filament, which allows for their distinctive motility. They are also gram-negative and are commonly found in the human oral cavity. However, they cannot be easily observed with brightfield microscopy as they are too thin and flexible, requiring specialized techniques such as darkfield or phase contrast microscopy.

Question 19

Which of the following pairs is mismatched?

Accepted Answer

Chemoautotrophic bacteria obtain energy by oxidizing inorganic substances and use carbon dioxide as a carbon source, but they do not fix atmospheric nitrogen. Nitrogen fixation is typically associated with certain bacteria like Rhizobium and cyanobacteria.

Question 20

Rickettsias differ from chlamydias in that rickettsias

Accepted Answer

The answer of Rickettsias differ from chlamydias in that rickettsias
...

Quiz 11: The Prokaryotes: Domains Bacteria and Archaea