Exam 2

Question 1

Typhoid fever is caused by bacteria of this genius

Answer 1

Salmonella

Question 2

Tapeworms obtain nutrients from a host’s

Answer 2

intestines

Question 3

Heartworm is caused by which organism?

Answer 3

Dirofilaria immitis

Question 4

EMB agar uses lactose and two dyes that allow it to be ____ between the blue-black colonies of E. coli and the pinkish colonies of all other enteric bacteria.

Answer 4

differential

Question 5

Which of the following causes syphilis?

Answer 5

Treponema pallidum

Question 6

The next day, while most of the family was out shopping, four of the family members were home with blurred vision, dry mouth, and muscle weakness. Mary called the family physician, Dr. Franklin, who told her to take the sick individuals to the emergency room, and he would meet them there. Upon arrival at the ER, Dr. Franklin asked what the family members had eaten for the meals before they developed the symptoms. The common foods that all of them ate were the chicken, the ham, the tomatoes, the green beans, and the spinach salad. The doctor determined that the family was suffering from botulism food poisoning. In the United States, foodborne botulism happens in 15% of cases each year, frequently from foods with a low acidity. He was suspicious of the green beans and tomatoes, even though tomatoes are highly acidic. Dr. Franklin also said that using proper methods of microbial control could have prevented their illness.

Which of the following is an example of microbial control?

Answer 6

• Sue uses bleach to clean the kitchen counters.
• Mary places leftovers in the refrigerator after the meal.
• Sue washes off the vegetables before serving them in a meal.

Question 7

Which genus of bacteria is responsible for more illnesses and diseases than any other group of bacteria?

Answer 7

Streptococcus

Question 8

What was the MOST likely source of the family’s botulism food poisoning?

Answer 8

The family consumed botulism toxin in the canned green beans.

Question 9

A water-soluble blue-green pigment is a characteristic of?

Answer 9

Pseudomonas aerigonosa

Question 10

Plasmodium, the cause of malaria, belongs to the phylum

Answer 10

Apicomplexa

Question 11

Peptic ulcers in humans are commonly caused by members of the genus

Answer 11

Helicobacter

Question 12

The parasite that causes African sleeping sickness is

Answer 12

Trypanosoma brucei

Question 13

Kissing bugs (Triatoma) transmit which disease?

Answer 13

Chagas disease

Question 14

Pathogenic microorganisms that are spread from person to person by unwashed hands contaminated by fecal matter is an example of what mode of transmission?

Answer 14

direct transmission

Question 15

A mutation that affects the genotype of the organism but not the phenotype is called a

Answer 15

silent mutation

Question 16

The diseases tetanus, botulism, and gas gangrene are associated with the genus

Answer 16

Clostridium

Question 17

During elongation, how is the RNA synthesized?

Answer 17

5’ to 3’

Question 18

Oncogenic viruses

Answer 18

cause tumors to develop

Question 19

How does the ribosome know if the entering charged tRNA is correct?

Answer 19

The anticodon on the tRNA base pairs to the codon on the mRNA.

Question 20

An index case

Answer 20

refers to the first case of an infectious disease outbreak to be identified

Question 21

Sampling lake water for microscopic organisms is not as easy as it sounds when you want to both count and identify species. In a given water sample, your bacteria of choice can be rare or difficult to culture, particularly given the mixture of bacteria in a biofilm. Which of the following culture media would be best for growing fecal coliforms when they are relatively less abundant than other bacteria in the lake?

Answer 21

enrichment culture medium

Question 22

An infection acquired in the hospital or other medical facility is called

Answer 22

nosocomial

Question 23

Bartonella henselae causes

Answer 23

cat-scratch disease

Question 24

An example of a latent viral infection is

Answer 24

cold sores

Question 25

An agar that uses the dye in crystal violet agar suppresses the growth of Gram-positive bacteria. This agar would be considered

Answer 25

selective

Question 26

Congenital infectious diseases

Answer 26

cross the placenta from infected mother to fetus

Question 27

During infection, *C. diphtheriae* expresses a variety of genes that are used to establish infection and cause disease. One of these genes encodes for diphtheria toxin. Expression of the toxin requires the genetic information contained in DNA be converted into protein. The 1st step in this process is transcription, in which DNA is converted into mRNA. The following is a short piece of the DNA sequence for diphtheria toxin (written 5’ to 3’): TAA GCG TAG AAC TTG. Which of the following sequences represents the mRNA (written 5’ to 3’) that will be generated from this template DNA sequence?

Answer 27

CAA GUU CUA CGC UUA

Question 28

A virus's ability to infect an animal cell depends primarily upon the

Answer 28

presence of receptor sites on the cell membrane

Question 29

Bacteria naturally prefer company instead of solitude for growth. Examples of this kind of communal growth pattern can be found everywhere, from surfaces of the teeth and the intestines, to the surface of a slimy rock in the lake, to the thick floc that clogs water pipes. These examples of communal bacterial growth are known by what name?

Answer 29

biofilm

Question 30

Worldwide spread of an infectious disease is called

Answer 30

pandemic

Question 31

During production of a drug, all work area surfaces must be disinfected using sterilized disinfectants. Which of the following statements about disinfectants are true?

Answer 31

* Endospores and viruses can resist disinfectant treatment. * Disinfection can occur by physical or chemical means. * Disinfectants are used to inhibit or destroy pathogens.

Question 32

A viroid is a(n)

Answer 32

infectious piece of RNA without a capsid

Question 33

Botulism food poisoning is a preventable illness if special precautions are taken during food preparation. In this case, what could Sue have done to prevent the outbreak of botulism?

Answer 33

* Sue noticed that the pressure cooker was malfunctioning during the canning process. She should have fixed the instrument, borrowed a properly working one, or purchased a new pressure cooker. * Sue could have boiled the food for at least 10 minutes before serving it to her family members.

Question 34

Diphtheria toxin kills eukaryotic cells by affecting translation. More specifically, the toxin prevents movement of tRNAs from the A site to the P site of the ribosome. Predict what the result(s) of this inhibition would be.

Answer 34

* New tRNAs will not be able to enter the ribosome. * Protein synthesis will be interrupted because the peptide chain is inhibited from growing.

Question 35

What characteristic of DNA allows two connected DNA polymerases to synthesize both the leading and lagging strands?

Answer 35

DNA is flexible.

Question 36

Which DNA strand is synthesized continuously?

Answer 36

leading strand

Question 37

After a period of rapid growth (log phase), bacterial growth rates will slow and enter the stationary phase. The number of viable cells no longer increases, but instead stays constant. In this activity you will indicate the statements that correctly describe what is happening during stationary phase.

Answer 37

The cells are likely running out of nutrients.

Question 38

sterilization

Answer 38

killing or removing all microorganisms on something

Question 39

disinfection

Answer 39

reducing pathogenic microorganisms

Question 40

antisepsis

Answer 40

killing or inhibiting the growth of microorganisms on living tissue

Question 41

degerming

Answer 41

physical removal of microbes by wiping/scrubbing

Question 42

sanitization

Answer 42

reducing pathogenic microbes on utensils and surfaces for public health

Question 43

biocide

Answer 43

a chemical that can kill living organisms

Question 44

germicide

Answer 44

a substance that kills pathogens

Question 45

bacteriostasis

Answer 45

a chemical/material that inhibits microbe growth

Question 46

asepsis

Answer 46

having no pathogenic microbes

Question 47

A disease that breaks out in explosive proportions within a population is called

Answer 47

epidemic

Question 48

An agar that uses a high salt concentration to limit the growth of one type of bacteria over another would be considered

Answer 48

selective

Question 49

A clear area against a confluent "lawn" of bacteria is called a

Answer 49

plaque

Question 50

A blood agar plate contains sheep red blood cells and allows for the determination of hemolytic capabilities for all bacteria that grow on the agar. This would make this type of agar

Answer 50

differential

Question 51

Sexually transmitted diseases are most often spread by what mode of transmission?

Answer 51

direct contact

Question 52

An infectious disease in which transmission can occur during the incubation period of disease is considered to be

Answer 52

communicable

Question 53

An infection in which the signs and symptoms are not recognized readily because they are too mild:

Answer 53

subclinical infection

Question 54

What is the basic function of the *lac* operon?

Answer 54

to code for enzymes involved in catabolizing lactose

Question 55

Patients in a hospital setting are typically more susceptible to infections than individuals in the general population and are considered to be

Answer 55

compromised

Question 56

When bacteria are inoculated into a new sterile nutrient broth, their numbers don’t begin to increase immediately. Instead, there is a lag phase that may last for an hour or even several days. Why don’t bacterial numbers increase immediately?

Answer 56

The bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes.

Question 57

What kind of bond is formed when two amino acids join together?

Answer 57

peptide bond

Question 58

What is the initial target of RNA polymerase?

Answer 58

the promoter