Amoeba Quick Quiz

Question 1

Amebas transform from trophozoites to cysts on entry into an unsuspecting human.

A. True
B. False

Answer 1

B. False

Question 2

Formed stool specimens are more likely to contain which of the following?

A. Trophozoites
B. Cysts

Answer 2

B. Cysts

Question 3

Infections with intestinal amebas are prevalent in which of the following?

A. Underdeveloped countries with poor sanitary
conditions
B. Beef consumers in the United States
C. People traveling to Europe
D. Japan, because of seafood diet

Answer 3

A. Underdeveloped countries with poor sanitary
conditions

Question 4

Which of the following structures is (are) typical in trophozoites of E. histolytica?

A. Single nucleus with a small karyosome
B. Unevenly distributed peripheral chromatin
C. Chromatoid bars D. Glycogen mass

Answer 4

A. Single nucleus with a small karyosome

Question 5

E. histolytica infection is traditionally diagnosed by finding which of the following?

A. Adult and egg forms of the parasite in a suspected
stool sample
B. Trophozoites and/or cysts in a suspected stool
sample
C. Larvae in a suspected CSF sample
D. Adult form of the parasite in suspected tissue
samples

Answer 5

B. Trophozoites and/or cysts in a suspected stool
sample

Question 6

The infective stage of E. histolytica is which of the following?
A. Trophozoite
B. Cyst

Answer 6

B. Cyst

Question 7

Which of the following factors is not responsible for the asymptomatic carrier state of a patient infected with E. histolytica?

A. Low virulence strain
B. Low inoculation into host
C. Intact patient’s immune system
D. Patient’s blood type

Answer 7

D. Patient’s blood type

Question 8

Which of the following prevention measures can control the spread of E. histolytica?

A. Drinking tap water
B. Using human feces as fertilizer
C. Boiling water or treat with iodine crystals
D. Practicing unsafe sex

Answer 8

C. Boiling water or treat with iodine crystals

Question 9

A main difference between the trophozoites of E. hartmanni and E. histolytica is which of the following?
A. Trophozoites of E. histolytica are smaller in size.
B. Presence of pseudopods
C. Trophozoites of E. hartmanni do not contain ingested red blood cells.
D. Nuclear structure and peripheral chromatin

Answer 9

C. Trophozoites of E. hartmanni do not contain ingested red blood cells.

Question 10

Which of the following is true regarding E. hartmanni?

A. The organism is found worldwide.
B. It is generally considered a pathogen and treat-
ment is indicated.
C. It is an extraintestinal ameba.
D. The life cycle

Answer 10

A. The organism is found worldwide.

Question 11

The trophozoites of E. coli:
A. Have eight nuclei
B. Have a typical nucleus consists of a large, often irregularly shaped karyosome that is eccentrically located
C. Are characterized by a karyosome that is surrounded by evenly distributed peripheral chromatin
D. Contain red blood cell inclusions

Answer 11

B. Have a typical nucleus consists of a large, often irregularly shaped karyosome that is eccentrically located

Question 12

Which of the following is not true about E. coli?

A. The parasite is found worldwide.
B. It is considered to be a pathogen.
C. The infection is transmitted through the ingestion of the infected cyst through contaminated food or drink.
D. The infection can be prevented by adequate dis- posal of human feces and good personal hygiene practices.

Answer 12

B. It is considered to be a pathogen.

Question 13

Which of the following statements is not true about the cysts of E. polecki?

A. Cysts vary in shape from spherical to oval.
B. Cysts contain at least four nuclei.
C. The typical cyst nucleus resembles that of E. histolytica.
D. A diffuse glycogen mass may be present in the cytoplasm of cysts.

Answer 13

B. Cysts contain at least four nuclei.

Question 14

Infection with E. polecki is mainly transmitted to humans via which of the following?

A. Ingestion of E. polecki trophozoite
B. Ingestion of E. polecki cysts
C. Humans do not get infected with E. polecki.
D. Touching an injected pig or monkey

Answer 14

B. Ingestion of E. polecki cysts

Question 15

The appearance of an E. nana karyosome is usually which of the following?

A. Granular
B. Large and round
C. Small and round
D. Blotlike

Answer 15

D. Blotlike

Question 16

Which of the following statements is true regarding E. nana?

A. E. nana is found primarily in cold regions of the world.
B. E.nanaisprevalentinareasinwhichpoorhygiene and substandard sanitary conditions exist.
C. E. nana is considered as a human pathogen, so treatment is mandatory.
D. Humans can obtain protection from E. nana via vaccination.

Answer 16

B. E.nanaisprevalentinareasinwhichpoorhygiene and substandard sanitary conditions exist.

Question 17

Iodamoeba bütschlii cysts typically:

A. Contain four nuclei
B. Have a small karyosome in a central position
C. Lack chromatoid bars
D. Lack a glycogen mass

Answer 17

C. Lack chromatoid bars

Question 18

Transmission of I. bütschlii occurs when:

A. The infective cysts are ingested in contaminated food or drink.
B. The infective trophozoites are ingested in contaminated food or drink.
C. Examining stool specimens from infected individuals
D. An infected mosquito vector bites an unsuspecting human.

Answer 18

A. The infective cysts are ingested in contaminated food or drink.

Question 19

Which of the following is a unique characteristic of E. gingivalis?

A. The trophozoites exhibit active motility via their pseudopods.
B. There is no known cyst form of this parasite.
C. The trophozoite has a single nucleus with characteristics that resemble those of E. histolytica.
D. E. gingivalis is the only ameba that may ingest white blood cells.

Answer 19

D. E. gingivalis is the only ameba that may ingest white blood cells.

Question 20

E. gingivalis:

A. Is an intestinal ameba
B. Is a pathogen and must be treated with
metronidazole
C. Can be found in the mouth and in the genital tract
D. Has a typical amebic life cycle (i.e., trophozoites and cysts)

Answer 20

C. Can be found in the mouth and in the genital tract

Question 21

The known morphologic forms of Naegleria fowleri are:

A. Ameboid trophozoites, flagellate forms, and cysts
B. Ameboid trophozoites, immature cysts, and mature cysts
C. Eggs, larvae, and adults
D. Flagellate forms, cysts, and larvae

Answer 21

A. Ameboid trophozoites, flagellate forms, and cysts

Question 22

The specimen of choice for the recovery of N. fowleri is which of the following?

A. Sputum
B. Stool
C. Cerebrospinal fluid
D. Urine

Answer 22

C. Cerebrospinal fluid

Question 23

Humans most often contract N. fowleri by which of the following?

A. Swimming in contaminated water
B. Kissing an infected person
C. Practicing unprotected sex
D. Ingestion of contaminated food

Answer 23

A. Swimming in contaminated water

Question 24

The ameboid trophozoites of N. fowleri enter the human body through all of the following routes except:

A. Entry through the nasal mucosa
B. Inhalation of contaminated dust
C. Sniffing contaminated water
D. Ingesting contaminated food and drink

Answer 24

D. Ingesting contaminated food and drink

Question 25

Practical measures for the control and prevention of N. fowleri include which of the following?

A. Banning swimming at all times during the summer months
B. Avoidance of chlorinating swimming pools and hot tubs
C. Providing education and awareness in the medical community
D. Avoidance of consuming contaminated food or water prior to swimming

Answer 25

C. Providing education and awareness in the medical community

Question 26

The term acanthopodia refers to:
A. Spinelike pseudopods
B. Hairy projections
C. Double-layer cell wall
D. Large karyosome and no obvious peripheral chromatin

Answer 26

A. Spinelike pseudopods

Question 27

The specimen of choice for diagnosing Acanthamoeba species trophozoites and cysts is which of the following?

A. Urine
B. Sputum
C. Cerebrospinal fluid
D. Stool

Answer 27

C. Cerebrospinal fluid

Question 28

Humans may acquire Acanthamoeba species by which of the following?

A. Aspiration or nasal inhalation of the organisms
B. Direct invasion of the parasites in the eye
C. Swimming or bathing in contaminated water
D. A or B

Answer 28

D. A or B

Question 29

Infections with Acanthamoeba species are encountered in which of the following anatomical parts?

A. Eye
B. Large intestines
C. Lungs
D. Liver

Answer 29

A. Eye

Question 30

To prevent infection with Acanthamoeba species, contact lens wearers should avoid which of the following?

A. Strenuous exercise
B. Foods with high carbohydrate content
C. Wearing clothing made of cotton
D. Using homemade nonsterile saline solutions

Answer 30

D. Using homemade nonsterile saline solutions

Question 31

Which of the following statements is not true about amebic trophozoites?

A. Trophozoites are delicate and motile.
B. Trophozoites are easily destroyed by gastric juices.
C. Trophozoites are resistant to the environment outside the host.
D. Replication occurs in the trophozoite stage.

Answer 31

C. Trophozoites are resistant to the environment outside the host.

Question 32

Amebic dysentery is caused by:

A. Entamoeba histolytica
B. Entamoeba coli
C. Entamoeba gingivalis
D. Endolimax nana

Answer 32

A. Entamoeba histolytica

Question 33

True/False. Treatment for patients with asymptomatic intestinal amebiasis is not recommended.

A. True
B. False

Answer 33

A. True

Question 34

Primary amebic meningoencephalitis is primarily caused by:

A. Entamoeba histolytica
B. Naegleria fowleri
C. Entamoeba gingivalis
D. Acanthamoeba spp.

Answer 34

B. Naegleria fowleri