Question

Assertion :Spongilla and Leucosolenia are not placed in same order. Reason: In Spongilla body is flattened or rounded, whereas in Leucosolenia body is radially symmetrical.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is incorrect but Reason is correct.

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.

Spongilla is a genus of freshwater sponges in the family Spongillidae found in lakes and slow streams and belongs to order Haplosclerida.

Leucosolenia is a genus of calcareous sponges belonging to the family Leucosoleniidae and order Leucosolenida.

In Spongilla body is flattened or rounded, whereas in Leucosolenia body is radially symmetrical.

Spongilla belongs to Haplosclerida, which belongs to class demosponges (their skeletons are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both), whereas Leucosolenia belongs to order Leucosolenida of class Calcarea (they are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite).

So, the correct answer is option B.