An organism exclusively with 70S type of ribosomes contains one of the following

Options

A. DNA enclosed with in a nuclear membrane
B. Circular naked DNA
C. Double stranded DNA with protein coat
D. Single stranded DNA with protein coat

Answer

To solve the question regarding an organism that exclusively contains 70S type of ribosomes, we need to analyze the characteristics of organisms that possess this type of ribosome.

### Step-by-Step Solution:

1. **Understanding 70S Ribosomes**:
- The "S" in 70S refers to the Svedberg unit, which measures the rate of sedimentation during centrifugation.
- 70S ribosomes are typically found in prokaryotic organisms (like bacteria) and in the mitochondria and chloroplasts of eukaryotic organisms.

2. **Identifying Characteristics of Prokaryotes**:
- Prokaryotic cells do not have a nucleus; instead, their genetic material is found in a region called the nucleoid.
- They usually contain circular, double-stranded DNA that is not associated with histones (hence termed "naked").

3. **Evaluating the Options**:
- **Option 1: DNA enclosed with nuclear membrane** - This describes eukaryotic cells, which have 80S ribosomes, not 70S. So, this option is incorrect.
- **Option 2: Circular naked DNA** - This aligns with the characteristics of prokaryotes, which possess circular, double-stranded DNA. This option is likely correct.
- **Option 3: Double stranded DNA with protein coat** - This suggests eukaryotic DNA that is associated with proteins (like histones), which is not characteristic of prokaryotes. Hence, this option is incorrect.
- **Option 4: Single stranded DNA with protein coat** - This does not fit the typical structure of prokaryotic DNA, which is double-stranded. Therefore, this option is also incorrect.

4. **Conclusion**:
- The only option that correctly describes an organism with 70S ribosomes is **Option 2: Circular naked DNA**. This is characteristic of prokaryotic organisms.

### Final Answer:
The organism exclusively with 70S type of ribosomes contains **circular naked DNA**.