Introduction

Question 1

define symbiosis brief

Answer 1

• living together
• describes two species of organisms that live together (no implication of length or outcome of association).
• usually symbionts are different species.

Question 2

symbiosis (4 types of interactions, what are they)

Answer 2

-phoresis (loose associations)
-commensalism (loose associations)
- mutualism (intimate associations)
-parasitism (intimate associations)

Question 3

what are the two types of loose associations in symbiosis?

Answer 3

phoresis , commensalism

Question 4

what are the two types of intimate associations in symbiosis

Answer 4

mutualism, parasitism

Question 5

what is phoresis

Answer 5

• means “to carry”
• when two symbionts are TRAVELING together
• no physiological or biochemical dependency required.
• host provides shelter/support/transport for a smaller organism (the phorant)

Question 6

what is commensalism

Answer 6

• ” I win” (+0)
• one member benefits and the other is not affected.
• involves feeding relationships and generally does not involve metabolic independence.

Question 7

what is mutualism

Answer 7

“I win- you win” (++)
- both species benefit from the association in terms of their growth and survival
- two way benefit- no harm

Question 8

parasitism

Answer 8

” I win- YOU LOSE” (+-)
- one benefits (parasite) off of the other (host)

Question 9

can you classify a bacterium or virus as a parasite?
why or why not?

Answer 9

NO

a parasite is a living organism (plant or animal) NOT bacteria or virus, that acquires some of its basic nutritional requirements through its intimate contact with another living organism.

• a parasite can live ON or IN a host organism.

Question 10

protozoans vs metazoans?

Answer 10

protozoans:
- unicellular organisms
- leishmania, plasmodium, giardia…

metazoans:
- multicellular organisms
- hookworm, tapeworm, roundworm, pinworm.

Question 11

Parasites can be classified as (3)

Answer 11

ectoparasite: a parasite that lives on the external surface of another living organism

endoparasite: a parasite that lives within another living organism

hemiparasite: a parasitic plant that derives some, or all, its sustenance from another plant.

Question 12

define a definitive host?

Answer 12

the organism in which the parasite reaches sexual maturity

Question 13

what is an intermediate host?

Answer 13

• the organism in which the parasite completed part of its life cycle
• parasite usually undergoes a morphological change in this host

Question 14

what is a reservoir host?

Answer 14

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

Question 15

define zoonosis

Answer 15

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

Question 16

what is an accidental host

Answer 16

• one that accidentally harbors a parasitic stage that is not usually parasitic in the particular species and cannot be transmitted

Question 17

what is a vector

Answer 17

• a host that plays an active role in the transmission of the parasite
• a living carrier that transports a pathogenic organism from an infected to a non-infected host
• the vector can be the definitive or intermediate host.

Question 18

classification of parasites (3 major groups of animal parasites)

Answer 18

• protozoans : unicellular endoparasites that include flagellates, amoebas
• helminths: multicellular parasitic worm that includes roundworms
• arthropods: a multicellular ectoparasite that includes insects and arachnids that are carriers (vectors of the disease)