Question

Totipotent cells of sponges are
A. Thesocytes
B. Archaeocytes
C. Myocytes
D. Chromocytes

Answer 1

Hint: Totipotent cells can be defined as the cell's ability to differentiate into some other type of cell. In sponges, Archaeocytes or amoebocytes are amoeboid cells found which are totipotent.

Complete answer:
Totipotent cells can be differentiated into other types of cells. The sponges are living animals which live in the water. They are known as Porifera. They are stuck to the floor in the oceans, sea, and rivers. For the specialized functions of sponges some specialized cells are found in them, such as choanocytes, porocytes, amoebocytes, and pinacocytes. Choanocytes help to trap and ingest food particles by phagocytosis. Porocytes control the amount of water that enters pores into the spongocoel. Amoebocytes are totipotent cells, they can be differentiated into other types of cells. Amoebocytes are also known as Archaeocytes. Pinacocytes maintain the size and structure of the sponge.

We have four options: Thesocytes, Archaeocytes, Myocytes, and Chromocytes.
> The thesocytes of sponges are usually binucleate and are packed with yolk platelets. These yolk platelets store food in the form of basic proteins and glycoproteins.

> Amoebocytes or Archaeocyte have various functions like they deliver nutrients from choanocytes to other cells of the sponge, they form eggs for sexual reproduction, they deliver phagocytized sperm from choanocytes to eggs and the most important is it can differentiate into more-specific cell types.

> Myocytes of sponge are small muscular cells whose function is opening and closing of the porocytes.

> Chromocytes are the modified amoebocytes. They are pigmented with lobose (thick, bulbous, blunt) pseudopodia.

Hence, the correct answer is option (B).

Note: Archaeocytes are undifferentiated embryonic amoebocytes having blunt pseudopodia and one large nucleus. These cells show totipotency and that's why archaeocytes play an important role in the regeneration of sponges.