Question

Given below are two statements:
Statement (I) : Males are shorter than females in Schistosoma sp.
Statement (II) : Female Schistosoma sp. carry male in the gynaecophoric canal during copulation
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

Remember that the male Schistosoma is the stouter partner that possesses the "gynaecophoric canal" (literally meaning "female-carrying canal") to hold the longer, slender female.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Blood flukes of the genus Schistosoma are unique among trematodes because they are dioecious (unisexual), meaning they have separate male and female individuals.
They exhibit distinct sexual dimorphism.
Detailed Explanation:
Let us evaluate both statements:
- Statement (I) analysis: In Schistosoma species, the adult male fluke is shorter, thicker, and stouter compared to the female. The adult female is longer, thinner, and thread-like. Thus, males are indeed shorter than females, making Statement (I) true.
- Statement (II) analysis: The adult male fluke has a ventral, longitudinal groove called the gynaecophoric canal. During copulation and for much of their adult life, the wider male carries the long, slender female within this canal, not the other way around. Thus, Statement (II) is false.

Step 2: Final Answer:
Since Statement (I) is true and Statement (II) is false, the correct choice is Option (C).