What is the difference between the trophozoite and cyst of Giardia lamblia?
Compared with many protists, Giardia lamblia has a simple life cycle alternating between cyst and trophozoite. Most research on the molecular biology of Giardia parasites has focused on trophozoites and the processes of excystation and encystation, whereas cysts have attracted less interest.
What are the characteristic features of Giardia?
Giardia lamblia has a characteristic tear-drop shape and measures 10-15 µm in length. It has twin nuclei and an adhesive disk which is a rigid structure reinforced by supelicular microtubules. There are two median bodies of unknown function, but their shape is important for differentiating between species.
What is happening during the trophozoite phase of Giardia?
Life Cycle The Giardia trophozoites then feed off and absorb nutrients from the infected person. Giardia trophozoites multiply by splitting in two in a process called longitudinal binary fission, remaining in the small intestine where they can be free or attached to the inside lining of the small intestine.
What kind of life cycle does Giardia have?
Giardia has one of the simplest life cycles of all human parasites. The life cycle is composed of 2 stages: (1) the trophozoite (see the first image below), which exists freely in the human small intestine; and (2) the cyst, which is passed into the environment. No intermediate hosts are required.
What is the incubation period of giardiasis?
Acute giardiasis develops after an incubation period of 1 to 14 days (average of 7 days) and usually lasts 1 to 3 weeks. Symptoms include diarrhea, abdominal pain, bloating, nausea, and vomiting.
How do you get a protozoan parasite?
Transmission of protozoa that live in a human’s intestine to another human typically occurs through a fecal-oral route (for example, contaminated food or water or person-to-person contact).
Which disease is caused by a protozoan parasite?
Many of the most prevalent and deadly human diseases are caused by a protozoan infection, including African Sleeping Sickness, amoebic dysentery, and malaria.
What is the difference between a parasite and a protozoa?
A protozoan went from being able to survive on its own in the environment to mooching off others. Protozoan parasites cannot live in the open environment on their own like other protozoa, but must invade another organism’s body to obtain protection and nourishment.