70 S ribosomes are found in

Options

A. Eukaryotic cell
B. Prokaryotic cell
C. Mitochondria
D. Both B and C

Answer

**Step-by-Step Solution:**

1. **Understanding Ribosome Types**: Ribosomes are cellular structures responsible for protein synthesis and can be classified based on their sedimentation coefficients, which are measured in Svedberg units (S). The main types of ribosomes are 70S, 80S, and 55S.

2. **Identifying 70S Ribosomes**: The 70S ribosome is composed of two subunits: a smaller 30S subunit and a larger 50S subunit. This structure is distinct from other ribosome types, such as the 80S ribosome, which consists of a 40S subunit and a 60S subunit.

3. **Locating 70S Ribosomes**: 70S ribosomes are primarily found in prokaryotic organisms. Prokaryotes include bacteria and archaea, which are unicellular organisms without a defined nucleus.

4. **Comparing with Other Ribosomes**: In contrast, 80S ribosomes are found in eukaryotic cells (like those of plants and animals), and 55S ribosomes are found in mitochondria, which are organelles within eukaryotic cells.

5. **Conclusion**: Based on the information gathered, we conclude that 70S ribosomes are found in prokaryotes.

**Final Answer**: 70S ribosomes are found in prokaryotes.

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