Exam 1 WileyPlus Quiz

Question 1

This scientist established a set of criteria to determine if a microbe is the cause of a specific disease.

Answer 1

Robert Koch

Question 2

Why did the broth in Pasteur’s experiment remain sterile?

Answer 2

The curve of the flask prevented bacteria from gaining access.

Question 3

This molecule was used to further characterize organisms from the domains Archaea.

Answer 3

rRNA

Question 4

Which metabolic pathway is the most energy efficient?

Answer 4

Aerobic respiration.

Question 5

Transcription is

Answer 5

RNA synthesis from a DNA template.

Question 6

Which of the following characteristics make microbes excellent model systems for experimentation?

Answer 6

• Fast generation times means numerous offspring in a short period of time.
• Some microbes are easy to culture in the laboratory.
• Microbial genomes are smaller and easier to manipulate.
• ALL OF THESE CHOICES!!

Question 7

__________ was primarily responsible for identifying the domain Archaea.

Answer 7

Carle Woese

Question 8

An important challenge in the global effort to battle infectious diseases is

Answer 8

A- access to vaccines and antibiotics is limited in many parts of the world.
B- the development of resistance to common antibiotics.
C- the lack of vaccines against several important diseases.
D- ALL THESE CHOICES ARE CORRECT

Question 9

Pasteur’s contributions to microbiology include

Answer 9

disproving the theory of spontaneous generation.

Question 10

Which of the following is not a characteristic that distinguishes living organisms from nonliving?

Answer 10

A- DNA as the genetic material (CORRECT)
B- Metabolism
C- Growth
D- Reproduction

Question 11

The presence of histones with the DNA of some archaeons suggests

Answer 11

archaea are more closely related to eukarya than bacteria.

Question 12

An unknown bacterial species has just gone through the Gram Stain procedure. What can we conclude if all of the bacteria stained pink after the application of Safranin?

Answer 12

The bacteria are Gram-negative.

Question 13

So far, all methanogens identified are

Answer 13

Strict anaerobes

Question 14

This structure is the powerhouse of the eukaryotic cell.

Answer 14

Mitochondrion

Question 15

One might assume that high population densities among microbes would be deleterious, leading to increased competition for limited resources and accumulation of potentially toxic waste products. However, there are several well documented examples where high densities are quite advantageous. How is this so?

Answer 15

A- Many hands make light work : large numbers of cells can accomplish tasks no individual cell could.
B- Safety in numbers : large numbers of cells will ensure some will be able to avoid predation or the host immune response.
C- Never too much of a good thing : large numbers of cells are able to modify their environment to their advantage, making it more favorable for their own survival.
D- ALL THESE CHOICES ARE CORRECT

Question 16

The _____ is the major site of active transport in a eukaryotic cell.

Answer 16

cell membrane

Question 17

Halophiles rely on a high intracellular concentration of which ion to maintain osmotic balance?

Answer 17

K+

Question 18

The decolorizer used in this procedure is _____.

Answer 18

alcohol

Question 19

If a cell is placed in a hypertonic solution,

Answer 19

water will move out of the cell.

Question 20

Fungi are differentiated from the other major groups of eukaryal microbes by

Answer 20

having cell walls made of chitin.

Question 21

Mannitol salt agar contains two key ingredients to grow Staphylococcus aureus. It contains the sugar mannitol which S. aureus is able to ferment but other Staphylococcus species cannot and it contains a high salt concentration which limits the growth of many different organisms. This media is:

Answer 21

Selective media and Differential media

Question 22

The ability of scrapie to be transmitted from sheep to sheep is evidence the disease

Answer 22

is caused by an infectious agent.

Question 23

You have completed a direct count of two broths. Broth A has 500 cells/ml and broth B has 1,000,000 cells/ml. What is true about these broths?

Answer 23

Broth B will have a higher optical density.

Question 24

What statement is true when comparing the following medias.

Answer 24

Selective media inhibits the growth of certain microorganisms while enrichment media allows the growth of microorganisms and enhances the growth of certain microorganisms

Question 25

Select the correct statement.

Answer 25

A- Low population densities will result in high OD readings.
B- High population densities will result in low OD readings.
C- A spectrophotometry is a direct method technique.
D- Spectrophotometers measure the turbidity of a sample. (CORRECT)

Question 26

Often times, when microorganisms are extracted from the environment, it is difficult to grow them in a culture in the laboratory. Why might this be?

Answer 26

A- The nutrients required for this microorganism are unknown.
B- The cofactors required for this microorganism are unknown.
C- The microorganism may be sensitive to nutrients in the media.
D- The nutrients and cofactors are available but the organism is incubated at the incorrect temperature.
E- All of these could be true. (CORRECT)

Question 27

The Baltimore classification system for viruses is based on

Answer 27

how mRNA is generated.

Question 28

Unlike taxonomy in plants and animals, taxonomy in viruses does not necessarily reflect evolutionary relatedness because

Answer 28

viruses most likely evolved from multiple lineages rather than a common ancestor.

Question 29

If the envelope of enveloped viruses is derived from the host cell during budding, how does the new viral particle recognize and attach to a new host cell?

Answer 29

Viral proteins needed for recognition and attachment on new host cells are embedded in the envelope.

Question 30

The shape of viruses is determined by their

Answer 30

Capsid