The passage through which movement of RNA and protein is molecules takes place in both directions is

Options

A. nuclear pore
B. Plasmodesmata.
C. Kinetochores
D. Nucleoli

Answer

To solve the question regarding the passage through which the movement of RNA and protein molecules takes place in both directions, we can analyze the options provided step by step.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a passage that allows the movement of RNA and protein molecules in both directions. This implies that the passage must facilitate transport from one cellular compartment to another and vice versa.

2. **Evaluating Option 1: Nuclear Pore**:
- Nuclear pores are large protein complexes that span the nuclear envelope.
- They regulate the transport of molecules between the nucleus and the cytoplasm.
- RNA (such as mRNA) is synthesized in the nucleus and transported to the cytoplasm through these pores.
- Proteins can also enter the nucleus through nuclear pores.
- **Conclusion**: Nuclear pores allow bidirectional movement of RNA and proteins. This option is likely correct.

3. **Evaluating Option 2: Plasmodesmata**:
- Plasmodesmata are microscopic channels that connect plant cells.
- They allow the transport of water, nutrients, and signaling molecules between adjacent plant cells.
- While they facilitate movement, they are not specifically involved in the transport of RNA and proteins in the context of the nucleus and cytoplasm.
- **Conclusion**: This option is not correct for the question.

4. **Evaluating Option 3: Kinetochores**:
- Kinetochores are protein structures on the chromosome where spindle fibers attach during cell division.
- They play a role in chromosome movement but do not facilitate the transport of RNA or proteins between cellular compartments.
- **Conclusion**: This option is not correct for the question.

5. **Evaluating Option 4: Nucleoli**:
- Nucleoli are structures within the nucleus where ribosomal RNA is synthesized and ribosome assembly begins.
- They do not function as passages for the transport of RNA and proteins.
- **Conclusion**: This option is not correct for the question.

6. **Final Conclusion**: Based on the evaluations, the correct answer is **Option 1: Nuclear Pore**, as it is the only structure that allows the movement of RNA and proteins in both directions between the nucleus and cytoplasm.