Nucleus is covered by

Options

A. Porous double membrane
B. Non-single membrane
C. Porous single membrane
D. Non-porous double membrane

Answer

### Step-by-Step Solution:

1. **Understanding the Nucleus**: The nucleus is a vital organelle found in eukaryotic cells. It is responsible for storing genetic material (DNA) and controlling cellular activities.

2. **Membrane Structure**: The nucleus is surrounded by a double membrane. This means there are two layers of membranes encasing the nucleus: an outer membrane and an inner membrane.

3. **Perinuclear Space**: Between the two membranes, there is a space known as the perinuclear space. This space separates the inner and outer membranes of the nucleus.

4. **Porosity of the Membranes**: Both the inner and outer membranes of the nucleus are porous. This means they contain pores that allow the passage of certain molecules. These pores form what is known as the nuclear pore complex.

5. **Function of Nuclear Pores**: The nuclear pore complex facilitates the transport and exchange of materials between the nucleus and the cytoplasm, allowing for communication and regulation of cellular functions.

6. **Conclusion**: Based on the structure and characteristics of the nucleus, we can conclude that the nucleus is covered by a **porous double membrane**.

### Final Answer:
The nucleus is covered by a **porous double membrane**.

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