Nucleic acid (DNA) is not found in -

Options

A. Nucleus & nucleolus
B. Peroxysome & ribosome
C. Mitochondria & plastid
D. Chloroplast & nucleosome

Answer

To determine where nucleic acid (DNA) is not found, we can analyze the options provided in the question. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Structure of DNA
DNA, or deoxyribonucleic acid, is the hereditary material in almost all living organisms. It is primarily located in the nucleus of eukaryotic cells, but it can also be found in certain organelles.

### Step 2: Analyze Each Option
1. **Nucleus**: The nucleus is the control center of the cell and contains the majority of the cell's genetic material in the form of DNA. Therefore, DNA is found in the nucleus.

2. **Nucleolus**: The nucleolus is a structure within the nucleus where ribosomal RNA (rRNA) is synthesized. While it is associated with the nucleus, it does not contain DNA itself.

3. **Peroxisome**: Peroxisomes are organelles that contain enzymes for various metabolic processes, including the breakdown of fatty acids and detoxification of hydrogen peroxide. They do not contain DNA.

4. **Ribosome**: Ribosomes are the sites of protein synthesis and are composed of ribonucleoprotein (RNA and proteins). They do not contain DNA.

5. **Mitochondrion**: Mitochondria have their own DNA, which is circular and resembles prokaryotic DNA.

6. **Plastid**: Plastids, such as chloroplasts, also contain their own DNA, similar to that of mitochondria.

7. **Nucleosome**: Nucleosomes are structural units of DNA packaging in eukaryotic cells and contain DNA wrapped around histone proteins.

### Step 3: Identify the Correct Answer
From the analysis, we can conclude that DNA is not found in:
- **Peroxisome**
- **Ribosome**

Thus, the correct answer is **peroxisome and ribosome**.

### Final Answer
Nucleic acid (DNA) is not found in **peroxisome and ribosome**.

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