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Flashcards in Terms Deck (30):
1

What are the three classes of protozoa?

Trypanosomatids, Apicomplexa, and other

2

How were protozoans discovered and what does the word mean?

protozoa= first animal. discovered with the invention of the microscope in 1675

3

What are the different groups of protozoans?

Amoebae, Flagellates, Ciliates, Sporozoa, Microsporidia

4

How big are protozoans?

10-50 microns (um)

5

Where do protozoans digest their food?

in vacuoles

6

Do protozoans have a cell wall?

no

7

Why are these protists considered to be animal-like?

they move like animals and have complex metabolic activity that is similar to animal cells. They resemble animal cells more than single cell

8

Define niche selection

selected to live in a specific essential niche defined by anatomical, physiological, and biochemical features of the site

9

What factors affect pathogenesis?

niche, metabolic requirements of the parasite, and population density

10

By which processes does food get into and out of the protozoa?

active transport, phagocytosis, pinocyotisis (IN)
diffusion or exocytosis (OUT)

11

By which means do ameoboids move?

pseudopodia (actin filaments rearranging along the cell membrane)

12

What is the movement difference between cilia and flagella?

cilia move back and forth in a flailing motion, flagella move in a rotational manner

13

By what methods do protozoa reproduce asexually?

binary fission, multiple fission (aka schizogony), and budding

14

By what methods do protozoa reproduce sexually?

conjugation and gamete fusion

15

When do we most often see sexual reproduction in protozoa?

in protozoa with an insect vector stage

16

Define trophozoite

any stage in a protozoan's life cycle that can digest food (the motile form usually)

17

Define cyst

non-motile form, protected by a membrane (infective stage)

18

Define excystation

process of emergence of the trophozoite from the cyst

19

Name some organisms in the apicomplexa?

toxoplasma (toxoplasmosis), plasmodium (malaria), cryptosporidium parvum (cryptosporidiosis)

20

What are some defining characteristics of Apicomplexans?

-all species are parasitic
-usually without cilia or flagella
-single type of nucleus
-have an apical complex involved in host cell penetration (gives the class its name)
-most have an apicoplast

21

What is the function of rhoptries, micronemes and dense granules in the apical complex?

they discharge substances into the host cell during the invasion process. They play a role in destabilizing the host cell membrane and forming an invasion pit

22

Why are apicoplasts considered plastids?

because drugs against chloroplasts and prokaryotes also kill apicomplexans

23

Describe the theory as to how apicomplexans have 4 cell membranes

eukaryotic heterotroph eats cyanobacterium (contains chloroplast), which was then engulfed by the apicomplexan ancestor

24

What is the function of an apicoplast?

possibly involved in lipid metabolism, is necessary for invading cells

25

Define sporogony

multiple fission of a zygote

26

Define sporozoite

daughter cell resulting from sporogony

27

Define oocyst

cystic form resulting from sporogony

28

Define schizogony

fission of sporozoites where multiple mitoses take place followed by simultaneous cytokineses, resulting in many daughter cells at once

29

Define gametogony

production of gametes

30

Define zygote

fusion of gametes