DNA is not present in `:`

Options

A. ribosomes
B. nucleus
C. mitochondria
D. choroplast

Answer

### Step-by-Step Solution:

1. **Understand the Question**: The question asks in which organelle DNA is not present. We need to evaluate each option provided.

2. **Evaluate the Nucleus**:
- The nucleus is known as the control center of the cell and contains the cell's genetic material, which is DNA.
- **Conclusion**: DNA is present in the nucleus.

3. **Evaluate Mitochondria**:
- Mitochondria are known as the powerhouse of the cell and they contain their own DNA, referred to as mitochondrial DNA (mtDNA).
- This DNA is circular and encodes essential genes for mitochondrial function.
- **Conclusion**: DNA is present in mitochondria.

4. **Evaluate Chloroplasts**:
- Chloroplasts are the sites of photosynthesis in plant cells and also contain their own DNA, known as chloroplast DNA (cpDNA or plastome).
- Each chloroplast can contain multiple copies of this DNA, which encodes various genes.
- **Conclusion**: DNA is present in chloroplasts.

5. **Evaluate Ribosomes**:
- Ribosomes are the cellular structures responsible for protein synthesis.
- Unlike the other organelles discussed, ribosomes do not contain any DNA. They are made up of ribosomal RNA (rRNA) and proteins.
- **Conclusion**: DNA is not present in ribosomes.

6. **Final Answer**: Based on the evaluations, the organelle where DNA is not present is **Ribosomes**.