The egg of which helminth can be concentrated in a saturated salt solution –
**Core Concept**
The question requires knowledge of the life cycle and diagnostic techniques of helminths, specifically the use of saturated salt solution to concentrate eggs for microscopic examination. This is a key concept in parasitology, crucial for the diagnosis and management of helminthic infections.
**Why the Correct Answer is Right**
The egg of *Ascaris lumbricoides* can be concentrated in a saturated salt solution due to its characteristic buoyancy in salt. The eggs of this large intestinal roundworm are excreted in the feces and can be concentrated using the floatation technique in a saturated salt solution. This technique is based on the principle that the eggs of *Ascaris* are more dense than the surrounding salt solution, causing them to sink, whereas other fecal contaminants will float. The eggs can then be examined microscopically for diagnosis.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as the eggs of *Trichuris trichiura* (whipworm) are not concentrated using a saturated salt solution.
**Option B:** Incorrect, as the eggs of *Taenia saginata* (beef tapeworm) are not concentrated using a saturated salt solution.
**Option C:** Incorrect, as the eggs of *Schistosoma mansoni* (blood fluke) are not concentrated using a saturated salt solution.
**Clinical Pearl / High-Yield Fact**
The floatation technique in a saturated salt solution is a simple and effective method for concentrating *Ascaris* eggs, but it is not suitable for other types of helminthic eggs. This is an important consideration in the diagnosis of helminthic infections.
**Correct Answer:** C. *Ascaris lumbricoides*.