biology - 5b - parasitic life cycles Flashcards
What do some hosts require?
Only one host to complete their life cycle.
What do many parasites require?
More than one host to complete their life cycle.
What is the definitive host?
The organism on or in
which the parasite reaches sexual maturity.
What may intermediate hosts also be required for?
The parasite to complete its life cycle.
What does a vector play an active role in?
The transmission of the parasite and may also be a host.
What is the human disease malaria caused by?
Plasmodium.
What does an infected mosquito, acting as a vector do?
Bites a human.
What does plasmodium do?
Enters the human bloodstream.
Where does asexual reproduction occur?
In the liver and then in the red blood cells.
What happens when the red blood cells burst?
Gametocytes are released into the bloodstream.
What does another mosquito do?
It bites an infected human and the gametocytes enter the mosquito, maturing into male and female gametes, allowing sexual reproduction to now occur.
What can the mosquito now do?
Infect another human host.
What do schistosomes cause?
The human disease schistosomiasis.
How do schistosomes reproduce?
Sexually in the human intestine.
What do the fertilised eggs do?
They pass out via faeces into water where they develop into larvae.
