Different types of cells are functionally iolated in which grade of organization ?

Options

A. Tissue level
B. cellular level
C. Organ level
D. Organ -system level

Answer

To answer the question "Different types of cells are functionally isolated in which grade of organization?", we can analyze the options provided step by step.

### Step-by-Step Solution:

1. **Understanding the Options**:
- We have four options: Tissue level, Cellular level, Organ level, and Organ system level. Each of these represents a different grade of biological organization.

2. **Tissue Level**:
- At the tissue level, cells that are structurally and functionally similar group together to perform a specific function. This means that all cells in a tissue are similar and work together, so different types of cells are not isolated here.

**Hint**: Remember that tissues consist of similar cells working together.

3. **Cellular Level**:
- The cellular level consists of individual cells that perform their own functions. In organisms like sponges (Porifera), there are different types of cells, but they operate independently without forming tissues. Thus, different types of cells are functionally isolated at this level.

**Hint**: Think about unicellular organisms and how they function independently.

4. **Organ Level**:
- At the organ level, tissues come together to form organs. For example, cardiac tissue forms the heart. Here, different types of tissues (composed of similar cells) work together, but they are not isolated as they function collectively.

**Hint**: Consider how organs are made up of different tissues working together.

5. **Organ System Level**:
- The organ system level consists of multiple organs working together to perform complex functions. For example, the circulatory system includes the heart, blood vessels, etc. Again, different types of cells are not isolated since they work in coordination.

**Hint**: Remember that organ systems involve multiple organs collaborating.

6. **Conclusion**:
- After analyzing all the options, we find that the correct answer is the **Cellular Level**. At this level, different types of cells exist, but they perform different functions independently, making them functionally isolated.

### Final Answer:
The answer is **Cellular Level** (Option 2).