quiz 1 (lectures 1&2)

Question 1

The modern tree of life, based on Carl Woese’s work, is based on sequence comparison of which gene?

A. ribosomal RNA (rRNA)
B. RNA polymerase gene
C. actin
D. lacl

Answer 1

A

Question 2

Why is ribosomal RNA especially useful for the study of phylogenetic relationships?

A. It is highly variable
B. It is only found in some species, helping them distinguish from others
C. It is highly variable
D. It is extremely short

Answer 2

C

Question 3

The first documented description of a microorganism was of a ___ by ___.

A. bacterium/Frederick Griffith
B. mold/Robert Hooke
C. fungus/Robert Koch
D. yeast/ Louis Pasteur

Answer 3

B

Question 4

Which of the following statements is correct?

A. Microorganisms represent a much smaller amount of Earth’s biomass than plants.
B. Microorganisms are significant in number, but not in overall biomass.
C. Microorganisms are significant contributors to the total biomass on Earth.
D. Microorganisms represent a much smaller amount of Earth’s biomass than animals.

Answer 4

C

Question 5

Which of the following statements about microbes is TRUE?

A. Algae are typically considered decomposers
B. Prions are non-infectious proteins with no nucleic acid
C. Archaea can be associated with extreme environments
D. Protozoa are nucleic acids without a protein coat

Answer 5

C

Question 6

Which of these puts the strength of chemical bonds in the correct order, from strongest to weakest?

A. hydrogen > ionic > covalent
B. hydrogen > covalent > ionic
C. covalent > hydrogen > ionic
D. ionic > covalent > hydrogen

Answer 6

D

Question 7

What field focuses specifically on the use of microbes to make products, sucha s antibiotics, on a large scale?

A. Microbial ecology
B. Industrial ecology
C. Biotechnology
D. Medical microbiology

Answer 7

C

Question 8

You sterilized media in a swan-neck flask (it isn’t sealed, but there is a bend in the glass between the media and the open air). You start working on other experiments and totally forget about it, leaving it undisturbed at the back of a shelf . Several months later, when you finally notice it, what is the most likely state of the media?

A. contaminated with microbes
B. sterile
C. dusty
D. radioactive

Answer 8

B

Question 9

According to our present understanding, each of the three major domains has what is known as its own universal ancestor.

T/F

Answer 9

F

Question 10

Which of these are eukaryotes?

A. archaea
B. viruses
C. fungi
D. bacteria

Answer 10

C

Question 11

Microbial cells first evolved on Earth approximately ___ billion years ago.

A. 7.0 to 7.2
B. 5.4 to 5.6
C. 3.8 to 4.3
D. 1.6 to 1.8

Answer 11

C

Question 12

Compared to Eukaryotes, Bacteria and Archaea have ________ surface-to-volume ratios, causing ________ nutrient exchange.

A. higher / higher
B. lower / higher
C. higher / lower
D. lower / lower

Answer 12

A

Question 13

Which of the following statements is FALSE?

A. Microbial cells are surrounded by a cytoplasmic membrane.
B. Microbial cells carry out metabolic processes
C. Microbial cells include both bacteria and viruses.
D. Microbial cells can exist as single cells.

Answer 13

C

Question 14

Who was the first researcher to provide direct experimental data that supported the germ theory to explain infectious disease?

A. Pasteur
B. Lister
C. Koch
D. Winogradsky

Answer 14

C

Question 15

Deduce why viruses are excluded from the ribosomal RNA-based tree of life.

A. Some viruses contain multiple strands of RNA.
B. Their genetic elements cannot be sequenced.
C. They can infect other organisms, which complicates the genetic comparisons.
D. They lack ribosomal RNA (rRNA).

Answer 15

D

Question 16

Pasteur flask has a(n)

A. swan neck to prevent particulate matter from getting into the main body of the flask.
B. double neck so two substances may be added at the same time.
C. secondary opening at the base to allow for drainage.
D. inverted upper edge to prevent spillage while swirling

Answer 16

A

Question 17

Which is a false statement about water?

A. Water molecules are polar
B. Hydrogen atoms in water form dipoles with a partial positive charge.
C. Water’s polarity allows for many ionic compounds to be dissolved in it.
D. Water has a high boiling point because of the extensive covalent bonding between molecules.

Answer 17

D

Question 18

Why do basic dyes attach to most bacterial surfaces?

A. Most bacterial surfaces do not have a charge
B. Most bacterial surfaces are negatively charged
C. Bacterial cells take up safranin.
D. Most bacterial surfaces resist taking up the stain.

Answer 18

B

Question 19

To avoid harsh staining which may change the structure of your sample, one can stabilize the sample by rapid freezing in liquid ethane with a ___.

A. Scanning electron microscope
B. Differential interference contrast microscope
C. Transmission electron microscope
D. Cryo-electron microscope

Answer 19

D

Question 20

What group of organisms, did Robert Whittaker add to his tree of life?

A. Bacteria
B. Archaea
C. Protists
D. Fungi

Answer 20

D

Question 21

Bacterial cells have a nucleus.

T/F

Answer 21

F

Question 22

Which of the following is/are characteristic of all cellular organisms?

A. Communication
B. Evolution
C. Communication, evolution, and motility
D. Motility

Answer 22

B

Question 23

Which type of staining results in a clear object being viewed against a dark background?

A.Endospore stain
B. Negative stain
C. Flagellar stain
D. Simple stain

Answer 23

B

Question 24

Electron microscopy has greater ________ than light microscopy, because the wavelength of visible light is much larger than the wavelength of electrons.

A. magnification
B. penetration
C. contrast
D. resolution

Answer 24

D

Question 25

Koch’s postulates were:

A. designed to establish a relationship between a causative microbe and a disease
B. specific to anthrax and tuberculosis but don’t apply to other diseases
C. interpreted as many organisms could cause the same disease
D. strict in that microorganisms isolated from experimentally inoculated hosts had to be different from the microorganism that was introduced into the host.

Answer 25

A