Fill in the blanks
_______ allows exchange of substances between nucleus and cytoplasm.

Explanation

**Step-by-Step Solution:**

1. **Identify the Components**: The question asks for a term that describes a structure facilitating the exchange of substances between two cellular components: the nucleus and the cytoplasm.

2. **Understand the Structure**: The nucleus is surrounded by a double membrane known as the nuclear membrane. This membrane is crucial for maintaining the environment of the nucleus.

3. **Focus on the Functionality**: The nuclear membrane is not just a barrier; it has specific structures that allow for the movement of materials. These structures are known as nuclear pores.

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