Intro

Question 1

What is the most dangerous animal on earth?

Answer 1

mosquito

Question 2

What percentage of animal species are parasitic at some stage in their life?

Answer 2

50%

Question 3

Which phylogenetic animal groups contain parasites?

Answer 3

All the major groups

Question 4

What are some common parasites in North America?

Answer 4

pinworms, giardia, dog roundworms, toxoplasma, ticks

Question 5

Where does the word ‘parasite’ come from?

Answer 5

Greek, meaning ‘one who eats at the table others’

Question 6

Are parasites prokaryoyes, eukaryotes, or both?

Answer 6

eukaryotes. therefore not bacteria or viruses

Question 7

Define protozoa

Answer 7

unicellular organisms

Question 8

Define metazoa

Answer 8

multicellular organisms

Question 9

Give some examples of ectoparasites

Answer 9

head lice, ticks, fleas

Question 10

Give some examples of endoparasites

Answer 10

hookworm, tapeworm, tapeworm eggs, roundworm, pinworm, leishmania, plasmodium, trypanosome, giardia

Question 11

Define hemiparasite

Answer 11

a parasitic plant that derives some or all of its sustenance from another plant

Question 12

Give an example of a hemiparasite

Answer 12

mistletoe attaches to another plant and absorbs its nutrients. spread by birds eating the fruit and pooping the seeds out

Question 13

Define host

Answer 13

the organism in or on which the parasite lives

Question 14

Define definitive host

Answer 14

the organism in which the parasite reaches sexual maturity

Question 15

Give an example of definitive host

Answer 15

the mosquito for malaria, the cat for toxoplasma

Question 16

Define intermediate host

Answer 16

the organism in which the parasite completes part of its life cycle. parasites usually undergo a morphological or physiological change in this host

Question 17

Give an example of intermediate host

Answer 17

humans for malaria, mice for toxoplasma

Question 18

Define reservoir host

Answer 18

alternate animal host from which the parasite can be transmitted to humans (zoonosis) or domestic animals

Question 19

Give an example of a reservoir host

Answer 19

the rat for toxoplasma

Question 20

Define zoonosis

Answer 20

a parasitic disease in which an animal is normally the host, but which also infects humans

Question 21

Define accidental host

Answer 21

one that accidentally harbors an organism that is not usually parasitic in the particular species and cannot be transmitted. parasite usually finds an immunologically privileged site (ie. brain, eyes, testes, etc)

Question 22

Give an example of an accidental host

Answer 22

humans and the pork tapeworm Taenia solium. causes human cysticercosis

Question 23

Define vector

Answer 23

a host that plays an active role in the transmission of the parasite. can be a definitive or an intermediate host

Question 24

Give an example of a vector

Answer 24

female Anopheles mosquito that transmits malaria

Question 25

What are some characteristics of parasites?

Answer 25

usually smaller and more numerous than their host, may be some degree of genetic complementation, parasite is physiologically or metabolically dependent upon its host, reproductive potential of parasites exceeds that of their host

Question 26

Why are many host-parasite interactions species-specific?

Answer 26

because of co-evolution

Question 27

What are the steps to parasite infection?

Answer 27

1) encounter 2) entry/attachment 3) spread within body 4) multiplication 5) damage 6) outcome- either parasite or host wins, or they coexist

Question 28

What are the main modes of parasite transmission?

Answer 28

skin, respiratory, gastrointestinal, urogenital | vector borne, blood transfusion, organ transplant

Question 29

What are the two types of vector borne transmission?

Answer 29

external and internal transmission

Question 30

Define harborage transmission

Answer 30

internal vector borne transmission where the pathogen does not undergo changes within vector (mechanical vector)

Question 31

Define biologic transmission

Answer 31

internal vector borne transmission where the pathogen undergoes changes within the vector (biological vector)

Question 32

Define infectivity

Answer 32

ability of the organism to establish a discrete, focal point of infection

Question 33

Define invasiveness

Answer 33

ability of organism to spread to adjacent or other tissues

Question 34

Define infection

Answer 34

a parasite growing and multiplying within or on a host, usually accompanied by an immune response

Question 35

Define pathogenicity

Answer 35

ability of parasite to cause disease

Question 36

Define virulence

Answer 36

degree of pathogenicity, the ability for the organism to invade, infect, grow and cause damage despite the host's defences. determine in part by pathogen's ability to survive outside the host

Question 37

Define symbiosis

Answer 37

living together

Question 38

What are the four types of symbiosis?

Answer 38

phoresis, commensalism, mutualism, and parasitism

Question 39

Define phoresis

Answer 39

'to carry'. when one organism is mechanically carried on or in another species (host)

Question 40

Give an example of phoresis

Answer 40

beetle with hitch-hiking mites, hermit crab carrying sea anemones, crab carrying a fire urchin

Question 41

Define commensalism

Answer 41

involves one way benefit, but no harm is exerted in either direction. usually involve a feeding relationship but not metabolic independence

Question 42

Give an example of commensalism

Answer 42

pilot fish attaches to shark and eats the debris from the shark's prey. egrets sit on livestock and eat insects surrounding them sea anemone protects clown fish, which has an extra mucous layer for protection from nematocyst discharge

Question 43

Define mutualism

Answer 43

highly inter-dependent association, often to the extent where the two cannot survive without one another

Question 44

Give an example of mutualism

Answer 44

flagellate protozoa live in termites and digest the wood for them. Yucca plant is only pollinated by yucca moths, and yucca moth larvae can only eat the seeds of yucca plants

Question 45

Define parasitism

Answer 45

intimate relationship between two organisms in which one lives on, off, or at the expense of the other (host)

Question 46

Give an example of parasitism

Answer 46

canine heartworm, malaria