Micro Final

Question 1

Contamination with ________ is a concern because they are highly resistant to killing.

Answer 1

endospores

Question 2

The ________ are the largest known group of archaea.

Answer 2

methanogens

Question 3

Cyanobacteria carry out the reactions of nitrogen fixation in specialized cells called

Answer 3

heterocysts

Question 4

Members of the genus ________ are Gram-positive bacteria that show a distinctive process for cell separation known as “snapping cell division”, form an arrangement known as “palisades”, and cause the disease diphtheria.

Answer 4

Corynebacterium

Question 4

Which of the following diseases is NOT associated with bacteria that form endospores?
tuberculosis, anthrax, botulism, gangrene, tetnus

Answer 4

tuberculosis

Question 5

Which bacterial genera produce(s) endospores?

Answer 5

Bacillus and Clostridium

Question 6

Which of the following bacterial genera includes species that protect areas of the body such as the intestinal tract and the vagina from invasion by pathogens?

Answer 6

Lactobacillus

Question 7

Members of which of the following genera are the most common sexually transmitted bacteria in the United States?

Answer 7

Chlamydia

Question 8

A flexible, spiral, corkscrew-shaped bacterium is called a

Answer 8

spirochete

Question 9

A Gram-positive rod-shaped ________ is a frequent contaminant of dairy products and meat and can cause fatal newborn meningitis.

Answer 9

Escherichia coli

Question 10

A _______ is a slightly curved rod.

Answer 10

vibrio

Question 11

What is a pleomorphic prokaryote?

Answer 11

a prokaryote whose cell morphology varies in shape and size

Question 12

Which of the following is NOT a means of reproduction in prokaryotes?
binary fission, meiosis, snapping division, budding

Answer 12

meiosis

Question 13

What is the difference between spores and endospores?

Answer 13

spores are reproductive structures and endospores are stable resting structures

Question 14

________ form when planes of cell division are random.

Answer 14

staphylococci

Question 15

Which of the following is NOT a taxonomic domain?
protista, archea, bacteria, eukarya

Answer 15

protista

Question 16

Scientists classify prokaryotes based on similarities in _______.
DNA, RNA, protein sequences

Answer 16

all of the above

Question 17

Which statement BEST describes the extent of our current knowledge of prokaryotes?

Answer 17

most prokaryotes have never been isolated or cultured

Question 18

Why are rRNA gene sequences an excellent tool for classifying bacteria?

Answer 18

genes are present in all known bacteria, part of the gene sequence is highly conserved, and part of the gene sequence varies from species to species

Question 19

Which statement MOST accurately describes the taxonomy of bacteria described in Bergey’s Manual?

Answer 19

bacteria are classified based on the consensus opinion of experts at a particular point in time

Question 20

Which of the following is NOT a difference between bacteria and archaea?

Answer 20

all archaea are extremophiles

Question 21

What is an extremophile?

Answer 21

a microbe that requires extreme conditions of temperature, pH, and/or salinity to survive

Question 22

How would you classify a microbe that requires temperatures over 80° C for growth?

Answer 22

hyperthermophile

Question 23

An organism that requires an environment containing greater than 9% NaCl would be considered a ________.

Answer 23

halophile

Question 24

Methanogens are obligate anaerobes that _______

Answer 24

convert CO2, H2, and organic acids into CH4

Question 25

Which answer best describes “deeply branching bacteria”?

Answer 25

Microbes that appear to be similar to the earliest bacteria

Question 26

An autotrophic bacterium ________.

Answer 26

produces organic compounds from carbon dioxide

Question 27

How are phototrophic bacteria classified?

Answer 27

based on their pigments and sources of electrons for photosynthesis

Question 28

According to the endosymbiotic theory, which group of phototrophic bacteria is MOST likely to have given rise to chloroplasts present in plants?

Answer 28

cyanobacteria

Question 29

What is nitrogen fixation?

Answer 29

the reduction of nitrogen gas to ammonia

Question 30

If organism X has a G + C content of 60% and organism Y has a G + C content of 35%, which of the following is most likely?

Answer 30

they are not closely related

Question 31

Which of the following is a unique characteristic of mycoplasmas?

Answer 31

they lack cell walls

Question 32

Which of the following does NOT have a high G + C content?

Answer 32

lactobacillus

Question 33

Which of the following is NOT a characteristic of Corynebacterium?

Answer 33

they have a low G + C content

Question 34

Which of the following is NOT a characteristic of the betaproteobacteria?

Answer 34

they are similar to alphaproteobacteria according to rRNA

Question 35

Which of the following is NOT a characteristic of pseudomonads?

Answer 35

they are in the deltaproteobacteria group

Question 36

Host specificity of a virus is due to

Answer 36

interactions between viral and cellular surface molecules

Question 37

Which of the following lists stages of a lytic replication cycle in order, from earliest to latest stages? I. Synthesis II. Assembly III. Attachment IV. Release V. Entry

Answer 37

III, V, I, II, IV

Question 38

A ________ is a bacterial virus which is integrated into the host cell DNA.

Answer 38

Prophage

Question 39

Reverse transcriptase is associated with which of the following?

Answer 39

retroviruses

Question 40

Naked capsid animal viruses are commonly released from the infected cell by ________, a process the host cell does not survive.

Answer 40

lysis

Question 41

A lipid membrane is present in which of the following?

Answer 41

enveloped viruses

Question 42

Which virus produces a rash and permanent scars on the skin, but has also been declared eradicated through mass vaccination?

Answer 42

Poxviridae

Question 43

An older adult is complaining of an intensely painful rash that has appeared as a patch on one side of his chest. This description is consistent with

Answer 43

shingles

Question 44

Diarrhea, nausea, and vomiting are signs and symptoms associated with which of the following viruses, particularly common in large gatherings of people like cruise ship vacations?

Answer 44

norovirus

Question 45

Which vaccine-preventable disease caused by an RNA virus has been nearly eradicated?

Answer 45

polio

Question 46

All of the following are characteristics of life EXCEPT _______ A. the ability to carry out metabolic processes B. the ability to grow and respond to the environment C. the ability to live in the presence of oxygen D. the ability to independently reproduce

Answer 46

the ability to live in the presence of oxygen

Question 47

acellular pathogens include _____, _______, ________

Answer 47

viruses, viroids, prions

Question 48

A virion is composed of a ________

Answer 48

capsid surrounding a nucleic acid core

Question 49

What is the size range of virus particles?

Answer 49

approximately 20 nm to 500 nm

Question 50

________ are the proteinaceous subunits that make up the viral capsid.

Answer 50

capsomeres

Question 51

What accurately describes lytic viral replication?

Answer 51

viral replication usually results in the death and lysis of the host cell

Question 52

What are 3 ways that viruses can cause human cancer?

Answer 52

Viruses can carry copies of oncogenes, promote/activate host cell oncogenes, and interferes with tumor suppressor genes

Question 53

The period of time required to complete the lytic cycle is called _______

Answer 53

the burst time

Question 54

How is the T4 virus able to penetrate the cell wall of E. coli?

Answer 54

it releases lysozymes, which weakens cell walls

Question 55

If one virus particle infects a cell, approximately how many infectious virus particles are present during the synthesis step of the virus replication cycle?

Answer 55

0

Question 56

What is the difference between phage T4 and lambda phage?

Answer 56

phage T4 uses lytic replication and lambda follows lysogenic replication

Question 57

A prophage is _______

Answer 57

a copy of the viral genome inserted into the host cell chromosome

Question 58

_______ may result in induction of prophage.

Answer 58

damage to the host cell's DNA

Question 59

Can a lysogenic virus ever switch to the lytic replication cycle?

Answer 59

Yes, but it can switch only after the viral DNA is excised from the host genome by induction

Question 60

A distinguishing characteristic of retroviruses is ______

Answer 60

they carry reverse transcriptase within their capsid

Question 61

_____, _______, ______ are used to culture animal viruses?

Answer 61

cultured cells, embryonated chicken eggs, and mature animals

Question 62

______ is a common and relatively inexpensive method for estimating numbers of phage.

Answer 62

a plaque assay

Question 63

What is the BEST method to use when attempting to culture bacteriophages?

Answer 63

mix the phages with bacteria in a liquid media and pour over an agar plate

Question 64

Diploid cell cultures can be derived from ______, _______, ______ cells.

Answer 64

embryonic animal, plant, and human

Question 65

How do scientists introduce virus particles to the inside of a chicken egg?

Answer 65

the virus particles are injected directly into specific embryonic tissues within the egg

Question 66

What are viroids?

Answer 66

small circular pieces of ssRNA that are infectious to plants

Question 67

How are viroids different from viruses?

Answer 67

viruses produce proteins and viriods produce free RNA that lack a protein coat

Question 68

What is a prion?

Answer 68

a proteinaceous infective particle

Question 69

How do disease-causing prions produce more disease-causing prions?

Answer 69

They change the shape of cellular PrP

Question 70

Prion diseases of the brain are called _______

Answer 70

spongiform encephalopathies

Question 71

What is an accepted argument for why viruses should be considered living?

Answer 71

They possess genomes with instructions for replicating themselves

Question 72

Merozoites are a result of

Answer 72

schizogony

Question 73

single-celled eukaryotes lacking a cell wall are

Answer 73

protozoa

Question 74

the ______ is the entire interwoven mass of one multicellular fungal organism

Answer 74

mycelium

Question 75

hyphae are associated with what?

Answer 75

molds

Question 76

lichens are composed of a symbiosis of fungi, ______, and _______

Answer 76

cyanobacteria, green algae

Question 77

An elderly woman is experiencing fever, chest pain, difficulty breathing, and a cough that occasionally brings up mucus containing blood. She reports having visited family in rural New Mexico over the Labor Day weekend. A sample from her lungs shows the presence of large spherules. Which of the following is the most likely infecting agent?

Answer 77

Coccidioides immitis

Question 78

What fungal infection was extremely rare prior to the AIDS epidemic?

Answer 78

Pneumocystis pneumonia

Question 79

Which of the following is the most common parasitic disease in industrialized nations?

Answer 79

Trichomonas infection

Question 80

After a trip to several South American countries, a middle-aged man becomes ill. He becomes anemic, loses weight, and runs a fever. The clinician notes a recently healed sore near his lip. The patient then seemingly improves and recovers. Several months later, the patient suddenly dies from congestive heart failure. What parasitic infection is considtent with this scenario?

Answer 80

leishmaniasis

Question 81

Which of the following organisms can colonize the nasal cavity and enter the brain to cause meningoencephalitis?

Answer 81

Naegleria