The genetic material (Genome) or DNA in prokaryotes / bacteria I E.coli and cyanobacteria occurs as

Options

A. one ds, tree circular DNA with histones
B. one ds, circular DNA without histones
C. histones with one linear ds DNA
D. Linear ss, one DNA without histones

Explanation

To answer the question regarding the genetic material (genome) or DNA in prokaryotes, specifically in E. coli and cyanobacteria, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Prokaryotes**:
- Prokaryotes are unicellular organisms that lack a nucleus and other membrane-bound organelles. They include bacteria and cyanobacteria.

2. **Identifying the Genetic Material**:
- The genetic material in prokaryotes is DNA. Unlike eukaryotes, where DNA is organized into linear chromosomes, prokaryotic DNA is organized differently.

3. **Structure of Prokaryotic DNA**:
- Prokaryotic DNA is typically circular in shape. This means that it forms a closed loop rather than being linear.

4. **Strandedness of DNA**:
- The DNA in prokaryotes is double-stranded. This means that there are two strands of DNA that are coiled together, forming a double helix structure.

5. **Presence of Histones**:
- In prokaryotes, histones (proteins that help package DNA) are generally absent. This is a key distinguishing feature of prokaryotic DNA compared to eukaryotic DNA, which is associated with histones.

6. **Conclusion**:
- Based on the characteristics of prokaryotic DNA, we can conclude that the genetic material in E. coli and cyanobacteria occurs as **one double-stranded circular DNA without histones**.

### Final Answer:
The correct answer is: **One double-stranded circular DNA without histones**.

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