Which of the following is not a basis of difference between plasmid and chromosomal DNA ?
a.Presence of histones
b. Nature of histones
c. Nature of nucleotide
d. Linear form of genetic material

Options

A. b & c only
B. a & d only
C. a , b , & d only
D. a , b , c & d

Answer

To determine which of the following options is not a basis of difference between plasmid and chromosomal DNA, we need to analyze each option in relation to the characteristics of plasmid and chromosomal DNA.

1. **Presence of histones**:
- Chromosomal DNA in eukaryotes is associated with histone proteins, which help in packaging the DNA into a compact structure. In contrast, plasmid DNA does not have histones associated with it. Therefore, this is a basis of difference between the two types of DNA.

2. **Nature of histones**:
- Since histones are not present in plasmid DNA, the nature of histones cannot be a basis of difference. If histones were present in both, we could compare their nature, but since they are absent in plasmids, this option does not serve as a basis of difference.

3. **Nature of nucleotide**:
- The nucleotides that make up both plasmid and chromosomal DNA are fundamentally the same in terms of structure (composed of a sugar, phosphate group, and nitrogenous base). Therefore, the nature of nucleotides is not a basis of difference between plasmid and chromosomal DNA.

4. **Linear form of genetic material**:
- Chromosomal DNA is typically linear in eukaryotes, while plasmid DNA is circular. This is a clear basis of difference between the two.

Based on the analysis above, the options that are not a basis of difference between plasmid and chromosomal DNA are:
- **b. Nature of histones**
- **c. Nature of nucleotide**

Thus, the correct answer is **b and c**.