Amphiblastula is the larva of A) Hydra B) Sycon

The correct answer is B) Sycon.

Explanation:

Amphiblastula is a type of larva found in some sponges, particularly in the genus Sycon. In the development of these sponges, the embryo forms a hollow ball of cells, which then undergoes differentiation to form the amphiblastula stage. This larval form is characterized by two distinct poles: one pole has flagellated cells, which help in movement, while the other pole is flatter and has non-flagellated cells. The amphiblastula stage is crucial for the dispersal of the sponge, as it allows the larva to swim through the water before eventually settling to develop into a mature sponge.

Here’s a quick overview of the options:

A) Hydra: Hydra is a cnidarian, and its larval stage is called a planula, not an amphiblastula.
B) Sycon: Sycon, a type of sponge, has the amphiblastula as its larval form.
C) Planaria: Planaria, a flatworm, does not have an amphiblastula; it typically undergoes a process called regeneration.
D) Leucosolenia: Leucosolenia is another genus of sponges, but it does not have an amphiblastula as its larval form.
Thus, the correct choice is B) Sycon.