The packaging of chromatin at a higher level requires an additional set of proteins that collectively are rerferred to as

Options

A. Small nuclear ribonucleoprotein (SnRNP)
B. Nucleoplasmin protein
C. Ribophorin protein
D. Non histone chromosomal proteins

Answer

To solve the question regarding the packaging of chromatin at a higher level, we will analyze each provided option and determine which one refers to the additional set of proteins involved in this process.

### Step-by-Step Solution:

1. **Understanding Chromatin Packaging:**
- Chromatin is a complex of DNA and proteins found in the nucleus of eukaryotic cells. The packaging of chromatin involves organizing DNA into a compact structure, which is essential for DNA replication, repair, and gene expression.

2. **Identifying the Options:**
- The options provided are:
- A) Small nuclear ribonucleoprotein (SNRNP)
- B) Nucleoplasmin protein
- C) Riboflurin protein
- D) Non-histone chromosomal proteins

3. **Analyzing Each Option:**
- **Option A: Small nuclear ribonucleoprotein (SNRNP)**
- SNRNPs are complexes of proteins and RNA that play a role in RNA processing, specifically in splicing. They are not involved in the higher-level packaging of chromatin.
- **Conclusion:** Incorrect option.

- **Option B: Nucleoplasmin protein**
- Nucleoplasmin is known to be the most abundant nuclear protein in certain organisms (like Xenopus oocytes) and is involved in chromatin remodeling. However, it does not specifically refer to the proteins required for higher-level chromatin packaging.
- **Conclusion:** Incorrect option.

- **Option C: Riboflurin protein**
- Riboflurin is involved in the binding of ribosomes to the rough endoplasmic reticulum and does not have a role in chromatin packaging.
- **Conclusion:** Incorrect option.

- **Option D: Non-histone chromosomal proteins**
- Non-histone chromosomal proteins are a diverse group of proteins that play crucial roles in the organization and compaction of chromatin into higher-order structures. They assist in the packaging of DNA and are essential for chromatin architecture.
- **Conclusion:** Correct option.

4. **Final Answer:**
- The correct answer is **D) Non-histone chromosomal proteins** as they are the additional set of proteins required for the higher-level packaging of chromatin.