Which statement about Giardia lamblia trophozoites is true?

Which statement about Giardia lamblia trophozoites is true?

• A. They are motile by flagella
• B. They have an undulating membrane
• C. They are non-motile
• D. They are rarely found in stool

Answer: (A)

Giardia lamblia trophozoites are actively motile thanks to their flagella. These organisms carry multiple flagella (eight in total, arranged as four pairs) that beat to propel the trophozoite through the intestinal lumen. This flagellar motion is a key feature that enables movement, colonization of the gut mucosa, and interaction with the host environment. The other statements don’t capture this essential trait of the trophozoite stage—motility by flagella is what sets this stage apart and drives its behavior in the host.

Giardia lamblia trophozoites are actively motile thanks to their flagella. These organisms carry multiple flagella (eight in total, arranged as four pairs) that beat to propel the trophozoite through the intestinal lumen. This flagellar motion is a key feature that enables movement, colonization of the gut mucosa, and interaction with the host environment. The other statements don’t capture this essential trait of the trophozoite stage—motility by flagella is what sets this stage apart and drives its behavior in the host.