Go through the following statements:
(i) a typical nucleosome contains 400 bp of DNA helix.
(ii) The positively charged DNA is wrapped around the negatively charged histoned octamer to form a structure called nucleosome.
(iii) Histones are rich in the basic amino acid residues asparagine ad valine
(iv) The packaging of chromatin at higher level requires additional set of proteins that collectively are referred to as nonhistone chromosomal proteins.
Find out the wrong statements:-

Options

A. (a) (i), (ii) & (iii)
B. (b) (ii), (iii) & (iv)
C. (c) (ii) & (iii)
D. (d) (i),(iii) & (vi)

Explanation

To determine the wrong statements from the provided options, let's analyze each statement step by step:

1. **Statement (i)**: "A typical nucleosome contains 400 bp of DNA helix."
- **Analysis**: A nucleosome is the fundamental unit of chromatin, consisting of a core of histone proteins around which DNA is wrapped. A typical nucleosome contains approximately 146 base pairs (bp) of DNA, not 400 bp. Therefore, this statement is incorrect.

2. **Statement (ii)**: "The positively charged DNA is wrapped around the negatively charged histone octamer to form a structure called nucleosome."
- **Analysis**: This statement is misleading. DNA is negatively charged due to its phosphate backbone, while histones are positively charged due to their basic amino acid composition. Thus, it is the negatively charged DNA that wraps around the positively charged histone octamer. This statement is incorrect.

3. **Statement (iii)**: "Histones are rich in the basic amino acid residues asparagine and valine."
- **Analysis**: Histones are indeed rich in basic amino acids, but the primary basic amino acids in histones are lysine and arginine, not asparagine and valine. Asparagine is actually a polar amino acid, and valine is a non-polar amino acid. Therefore, this statement is also incorrect.

4. **Statement (iv)**: "The packaging of chromatin at a higher level requires an additional set of proteins that collectively are referred to as nonhistone chromosomal proteins."
- **Analysis**: This statement is correct. Nonhistone chromosomal proteins play a crucial role in the higher-order structure of chromatin and are essential for the proper packaging of DNA within the nucleus.

**Conclusion**: The wrong statements are (i), (ii), and (iii).

### Final Answer:
The wrong statements are:
- (i) A typical nucleosome contains 400 bp of DNA helix.
- (ii) The positively charged DNA is wrapped around the negatively charged histone octamer to form a structure called nucleosome.
- (iii) Histones are rich in the basic amino acid residues asparagine and valine.