Protozoa

Question 1

Symbiosis

Answer 1

Close and prolonged interaction between organisms of different species. A long term relationship. Parasitism, commensalism or mutualism.

Question 2

Symbiont

Answer 2

Induviduals involved in a symbiosis.

Question 3

Parasitism

Answer 3

Symbiotic relationship between 2 different species where one member benefits and the other is harmed.

Question 4

Parasite

Answer 4

Organism that live in or on a host and gains its nourishment at the expense of the host.

Question 5

Obligatory Parasite

Answer 5

A parasite that cannot exist outside its host.

Question 6

Facultative Parasite

Answer 6

A parasite that can exist independdent of its host

Question 7

Endoparasite

Answer 7

Parasite that is established inside the host’s body.

Question 8

Ectoparasite

Answer 8

Parasite that is established in or on the exterior surface of its host.

Question 9

Host

Answer 9

Species of animal or plant that harbors a parasite

Question 10

Definitive Host

Answer 10

Host in which the adult and/or sexual phase of the parasite occurs.

Question 11

Intermediate Host

Answer 11

Host in which the larval and/or asexual phase of the parasite occurs

Question 12

Accidental/Incidental Host

Answer 12

Host other than the normal host that harbors a parasite.

Question 13

Reservoir Host

Answer 13

Host that harbors a parasite that is also parasitic for humans and from which humans can become infected.

Question 14

Infective Stage

Answer 14

Stage in the parasitic life cycle that is capable of invading a definitive host.

Question 15

Diagnostic Stage

Answer 15

Stage in the parasitic life cycle that can be identified by examining appropriate specimens from the host.

Question 16

Infestation

Answer 16

Parasitic infection, especially for macroscopic parasites.

Question 17

Amoebas

Answer 17

Class of parasites
Move via Pseudopods
Replicate via Binary Fission
Found in nature
Most are nonpathogenic

Question 18

Trophozoite

Answer 18

Motile stage of most parasitic amoebas and flagellates
Feeding
Find in darrheal stools
Noninfectious

Question 19

Cysts

Answer 19

Nonmotile stage of most parasitic amoebas and flagellates
Protected by cyst wall
Resistant to drying and gastric acid
Infectious

Question 20

Life cycle of intestinal amoebas (Entamoeba histolytica)

Answer 20

1. Host ingests infective cysts
2. Cysts in GI tract excyst to form trophozoite
3. Troph multiplies by binary fission
4. Troph encysts
5. Host excretes cysts in stool

Question 21

How to identify trophozoites

Answer 21

Size
Arrangements of chromatin in nucleus
“Clean” vs. “dirty” cytoplasm
Presence or absence of inclusions in cytoplasm

Question 22

How to identify cysts

Answer 22

Size
Shape
# of nuclei
Presence or absence of chromatid bodies or other inclusions in cytoplasm

Question 23

Entamoeba hystolytica diseases and transmission

Answer 23

Dysentery - bloody diarrhea (trophs)
Ulcers - in liver, brain and colon
Transmitted in food, water, sexually
Cysts viable for 30 days

Question 24

Dientamoeba fragilis diseases and transmission

Answer 24

Diarrhea, abdominal pain, anorexia, nausea, vomiting, fatigue and weight loss
No cyst stage
Transmitted in food and water

Question 25

Ciliates

Answer 25

Ciliated trophozoites | Balantidium coli is only known ciliate parasite of humans

Question 26

Balantidium coli diseases and transmission

Answer 26

Only known ciliate parasite in humans and largest protozoan in humans Balantidiasis Transmitted in food and water

Question 27

Flagellates

Answer 27

Flagellated trophozoites | Giardia and Trichomonas

Question 28

Giardia duodenalis/lamblia diseases and transmission

Answer 28

"Little old man with glasses" appearance Giardiasis - 1-14 day incubation, lasts 1-3 weeks, acute or chronic diarrhea, nausea and vomiting, followed by foul smelling stool Transmission by fecal/oral route in water

Question 29

Trichomonas vaginalis diseases and transmission

Answer 29

Vaginosis - not a pathogen per se, but causes pH and other imbalance in the vagina Transmitted sexually No cyst stage

Question 30

Zoonotic Diseases

Answer 30

A disease that can be transmitted from animals to people. | Usually exists only in animals but can be transmitted to humans

Question 31

Cryptosporidium parvum diseases and transmission

Answer 31

Causes mild, self-limiting watery diarrhea (small bowel) Remission ~ 10 days Transmission in water, food, animals and people Resists chlorine and ozone treatments

Question 32

Characteristics of Protozoa

Answer 32

Eukaryotes Membrane bound nucleus Etc.

Question 33

Sequelae

Answer 33

Diseases that can come as a result of and following another disease