Terms

Question 1

What are the three classes of protozoa?

Answer 1

Trypanosomatids, Apicomplexa, and other

Question 2

How were protozoans discovered and what does the word mean?

Answer 2

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

Question 3

What are the different groups of protozoans?

Answer 3

Amoebae, Flagellates, Ciliates, Sporozoa, Microsporidia

Question 4

How big are protozoans?

Answer 4

10-50 microns (um)

Question 5

Where do protozoans digest their food?

Answer 5

in vacuoles

Question 6

Do protozoans have a cell wall?

Answer 6

no

Question 7

Why are these protists considered to be animal-like?

Answer 7

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

Question 8

Define niche selection

Answer 8

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

Question 9

What factors affect pathogenesis?

Answer 9

niche, metabolic requirements of the parasite, and population density

Question 10

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

Answer 10

active transport, phagocytosis, pinocyotisis (IN)

diffusion or exocytosis (OUT)

Question 11

By which means do ameoboids move?

Answer 11

pseudopodia (actin filaments rearranging along the cell membrane)

Question 12

What is the movement difference between cilia and flagella?

Answer 12

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

Question 13

By what methods do protozoa reproduce asexually?

Answer 13

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

Question 14

By what methods do protozoa reproduce sexually?

Answer 14

conjugation and gamete fusion

Question 15

When do we most often see sexual reproduction in protozoa?

Answer 15

in protozoa with an insect vector stage

Question 16

Define trophozoite

Answer 16

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

Question 17

Define cyst

Answer 17

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

Question 18

Define excystation

Answer 18

process of emergence of the trophozoite from the cyst

Question 19

Name some organisms in the apicomplexa?

Answer 19

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

Question 20

What are some defining characteristics of Apicomplexans?

Answer 20

• 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

Question 21

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

Answer 21

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

Question 22

Why are apicoplasts considered plastids?

Answer 22

because drugs against chloroplasts and prokaryotes also kill apicomplexans

Question 23

Describe the theory as to how apicomplexans have 4 cell membranes

Answer 23

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

Question 24

What is the function of an apicoplast?

Answer 24

possibly involved in lipid metabolism, is necessary for invading cells

Question 25

Define sporogony

Answer 25

multiple fission of a zygote

Question 26

Define sporozoite

Answer 26

daughter cell resulting from sporogony

Question 27

Define oocyst

Answer 27

cystic form resulting from sporogony

Question 28

Define schizogony

Answer 28

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

Question 29

Define gametogony

Answer 29

production of gametes

Question 30

Define zygote

Answer 30

fusion of gametes