MEDICAL PARASITOLOGY A SELF
INSTRUCTIONAL TEXT LEARNING WORKBOOK
2026 PROTOZOA HELMINTHS AND
ARTHROPOD VECTORS
◉ What is commensalism?
Answer: A relationship where one organism gains while the other is
neither harmed nor helped.
◉ Define mutualism.
Answer: A symbiotic relationship where both organisms benefit.
◉ What is parasitism?
Answer: A relationship where one organism (the parasite) gains
food and shelter from another (the host), which suffers from the
relationship.
◉ What is an endoparasite?
Answer: A parasite that lives inside the body of the host.
◉ What is an ectoparasite?
Answer: A parasite that lives outside the body of the host.
,◉ What is an obligate parasite?
Answer: A parasite that needs a host at some stage of its life cycle to
complete development.
◉ What is a facultative parasite?
Answer: A parasite that may exist in a free-living state but becomes
parasitic when the need arises.
◉ What defines a definite or final host?
Answer: The organism in which the mature stage of the parasite
lives.
◉ What is an intermediate host?
Answer: An organism in which the parasite lives during a period of
its larval or asexual development.
◉ What is a paratenic host?
Answer: A host that serves as a transport for the parasite without
undergoing development.
◉ What is contact transmission?
, Answer: Infection that is transmissible directly from person to
person.
◉ What is soil-transmitted infection?
Answer: An infection where the infective stage becomes infective
after a period of incubation in the soil.
◉ What is arthropod transmission?
Answer: Infection transmitted by an arthropod intermediate host
which bites or is ingested by humans.
◉ What is congenital transmission?
Answer: Transmission of infection from mother to child during
pregnancy or childbirth.
◉ What are trophozoites?
Answer: The motile feeding form of protozoa.
◉ What are cysts in the context of protozoa?
Answer: The non-motile, non-reproducing form of protozoa that is
often involved in transmission.
◉ What is a biological vector?
INSTRUCTIONAL TEXT LEARNING WORKBOOK
2026 PROTOZOA HELMINTHS AND
ARTHROPOD VECTORS
◉ What is commensalism?
Answer: A relationship where one organism gains while the other is
neither harmed nor helped.
◉ Define mutualism.
Answer: A symbiotic relationship where both organisms benefit.
◉ What is parasitism?
Answer: A relationship where one organism (the parasite) gains
food and shelter from another (the host), which suffers from the
relationship.
◉ What is an endoparasite?
Answer: A parasite that lives inside the body of the host.
◉ What is an ectoparasite?
Answer: A parasite that lives outside the body of the host.
,◉ What is an obligate parasite?
Answer: A parasite that needs a host at some stage of its life cycle to
complete development.
◉ What is a facultative parasite?
Answer: A parasite that may exist in a free-living state but becomes
parasitic when the need arises.
◉ What defines a definite or final host?
Answer: The organism in which the mature stage of the parasite
lives.
◉ What is an intermediate host?
Answer: An organism in which the parasite lives during a period of
its larval or asexual development.
◉ What is a paratenic host?
Answer: A host that serves as a transport for the parasite without
undergoing development.
◉ What is contact transmission?
, Answer: Infection that is transmissible directly from person to
person.
◉ What is soil-transmitted infection?
Answer: An infection where the infective stage becomes infective
after a period of incubation in the soil.
◉ What is arthropod transmission?
Answer: Infection transmitted by an arthropod intermediate host
which bites or is ingested by humans.
◉ What is congenital transmission?
Answer: Transmission of infection from mother to child during
pregnancy or childbirth.
◉ What are trophozoites?
Answer: The motile feeding form of protozoa.
◉ What are cysts in the context of protozoa?
Answer: The non-motile, non-reproducing form of protozoa that is
often involved in transmission.
◉ What is a biological vector?
