Nucleus is the site of

Options

A. m-RNA systhesis
B. assemblage of ribosomal units
C. both (1) & (2)
D. DNA and protein synthesis

Answer

### Step-by-Step Solution:

1. **Understanding the Nucleus**: The nucleus is a vital organelle in the cell, often referred to as the "brain of the cell" due to its central role in regulating cellular activities.

2. **Functions of the Nucleus**: The nucleus is primarily involved in two major processes:
- **mRNA Synthesis**: The nucleus is the site where messenger RNA (mRNA) is synthesized from the DNA template. This process is known as transcription.
- **Ribosome Assembly**: The nucleus is also the site where the initial assembly of ribosomal units occurs. Ribosomes are essential for protein synthesis.

3. **Transport of mRNA**: After mRNA is synthesized in the nucleus, it is transported out to the cytoplasm through nuclear pores. In the cytoplasm, mRNA serves as a template for protein synthesis during the process of translation.

4. **Conclusion**: Therefore, the nucleus is the site for both mRNA synthesis and the assembly of ribosomal units. This makes it a crucial component in the overall process of gene expression and protein synthesis.

### Final Answer:
The nucleus is the site of both mRNA synthesis and the assemblage of ribosomal units.

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