In poriferans, the rudimentary division of labour is present between_______.

Options

A. cells
B. tissues
C. organs
D. organ-systems

Explanation

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks about the rudimentary division of labor in poriferans, which are organisms belonging to the phylum Porifera.

2. **Identify the Organisms**: Poriferans are commonly known as sponges. They are characterized by their porous bodies and are non-motile multicellular organisms.

3. **Recognize the Level of Organization**: Poriferans exhibit a cellular level of organization. This means that their body is made up of loose aggregates of cells rather than organized tissues, organs, or organ systems.

4. **Define Division of Labor**: Division of labor refers to how different parts of an organism contribute to various functions. In more complex organisms, this is seen in the specialization of tissues and organs.

5. **Analyze the Options**:
- **Cells**: Since poriferans only have a cellular level of organization, the division of labor occurs among the individual cells.
- **Tissues**: This option is incorrect because poriferans do not have true tissues; they only have aggregates of cells.
- **Organs**: This option is also incorrect as poriferans do not possess organs.
- **Organ Systems**: This option is incorrect as well, as poriferans lack organ systems.

6. **Conclusion**: The correct answer is that the rudimentary division of labor in poriferans is present between **cells**.

---