Question

Proterospongia is a connecting link between
A. Protozoa and Porifera
B. Porifera and Coelenterata
C. Protozoa and Annelida
D. Porifera and Annelida

Answer 1

Hint: It bears the characteristics of a free-living marine, they move with the help of flagella. They have the characteristic of sponges.

Complete Answer:
- Proterospongia is a protozoan of colonial origin. It is composed of flagellated and collared individuals resembling sponges' choanocytes (collar cells). This is, thus, the relation between Protozoa and Porifera.
- Porifera and coelenterata is not a connecting link of Proterospongia because this species does not bear the characteristics of each of these. Therefore, the option B is incorrect.
- Proterospongia has a link with Protozoa because of its form but does not have a link with Annelida because Proterospongia does not bear any characteristics of Annelida. Therefore, the option C is incorrect.
- Proterospongia has a link with Porifera because it bears the characteristics ie., sponges of porifera but Proterospongia does not bear any characteristics of Annelida. Therefore, the option D is incorrect.

Thus, the correct answer is option A Protozoa and Porifera.

Note: Proterospongia can be referred to as Salpingoeca as well. A class of single-celled marine species that build colonies is Proterospongia. It belongs to a class of choanoflagellates. Proterospongia is of interest to researchers as a colony-forming choanoflagellate, researching the mechanisms of intercellular signalling and adhesion occurring before animals formed.