LAB FINAL EXAM

Question 1

T or F

Chaga’s disease is transmitted by the Black fly.

Answer 1

False- kissing beetle

Question 2

T or F

The definitive host for anisakis is a snail.

Answer 2

False- marine mammals

Question 3

T or F

Amoebic dysentery is caused by cryptosporidium parvum.

Answer 3

False

Question 4

T or F

Giardiardiasis can be transmitted by the TseTse Fly.

Answer 4

False- contaminated water

Question 5

T or F

Humans are the definitive host for Toxoplasma gondii.

Answer 5

False- accidental host

Question 6

T of F

A vector is an Arthropod that transmits a parasite to a host.

Answer 6

True

Question 7

T or F

Humans get malaria by drinking water contaminated with Naegleria.

Answer 7

False

Question 8

T or F

On MacConkey Agar, lactose fermenters form dark blue colonies.

Answer 8

False- pink

Question 9

Coliform:

Answer 9

Gram (-)
Rods
Non-spore forming
Facultative anaerobe 
Ferment lactose

Question 10

MPN:

Answer 10

Most probable number

Question 11

Selective media:

Answer 11

Allows the growth of some organisms while inhibiting the growth of other

Question 12

Differential media:

Answer 12

Differentiates closely related organisms based on the organism’s biochemical characteristics

Question 13

Conjugation:

Answer 13

DNA from one cell is transferred to another cell to produce a new recombinant cell

Question 14

Transformation:

Answer 14

Insertion of a gene into an organism in order to change the organism’s trait

Question 15

Plasmid: (4)

Answer 15

• Double stranded circular DNA that carry specialized genes
• Can move from one bacterial cell to another
• Can be exchanged between cells of different species
• Can replicate independently of bacterial chromosome

Question 16

Staphylococci:

Answer 16

Gram (+)
Spherical
Non-spore forming

Question 17

S. aureus:

Answer 17

Causes nosocomial infections

Question 18

3 tests done to determine the coliform count in water:

Answer 18

1. Presumptive
2. Confirmed
3. Completed

Question 19

MacConkey agar contains:

Answer 19

Bile salts and crystal violet which inhibit gram (+) bacteria

Question 20

Prevalence:

Answer 20

Total number people infected at any one time

-no cure (i.e. HIV)

Question 21

Epidemic:

Answer 21

Sudden increase of a disease in population

Question 22

Pandemic:

Answer 22

Worldwide outbreak

Question 23

Endemic:

Answer 23

Always present in the population of a certain geographic area

Question 24

Incidence:

Answer 24

Number of new cases of a disease in a population

Question 25

Sporadic disease:

Answer 25

An occurrence of random, isolated cases

Question 26

Etiology:

Answer 26

Cause or origin of disease

Question 27

Mortality rate:

Answer 27

Number of deaths per 100,000 people per year

Question 28

Epidemiology:

Answer 28

Study of the factors and mechanisms involved in the frequency and spread of disease

Question 29

How is MacConkey agar selective?

Answer 29

Selective for gram (-) bacteria because bile salts and crystal violet inhibit the growth of gram (+)

Question 30

How is MacConkey agar differential?

Answer 30

Differential based on ability to ferment lactose (bacteria that can ferment lactose cause a drop in pH which turns indicator pink)

Question 31

Common source outbreak:

Answer 31

Contact with contaminated substances (food poisoning)

Question 32

Propagated epidemic:

Answer 32

Person to person contact (horizontal transmission, common cold)

Question 33

Intermediate host:

Answer 33

Host that harbors the larval or asexual stage

Question 34

Definitive host:

Answer 34

Harbors the adult or sexual stage of the parasite-adulthood and mating of helminths

Question 35

Reservoir host:

Answer 35

Nonliving reservoirs of infectious disease found in soil and water

Question 36

Accidental host:

Answer 36

Can serve as a host, but is not the usual host in the parasites life cycle

Question 37

Endoparasites:

Answer 37

Parasites that live inside the host’s body

Question 38

Ectoparasites:

Answer 38

Parasites that live outside the host’s body