Universal smaller sub unit of ribosome is

Options

A. 30S
B. 40S
C. 50S
D. 60S

Answer

To determine the universal smaller subunit of ribosomes, we can follow these steps:

### Step 1: Understand Ribosome Structure
Ribosomes are made up of two subunits: a larger subunit and a smaller subunit. In prokaryotes, the ribosome is typically referred to as 70S, which consists of a 50S large subunit and a 30S small subunit. In eukaryotes, the ribosome is referred to as 80S, which consists of a 60S large subunit and a 40S small subunit.

### Step 2: Identify the Smaller Subunit
The question specifically asks for the universal smaller subunit of ribosomes. In prokaryotes, the smaller subunit is the 30S, while in eukaryotes, it is the 40S. However, the question is looking for a universal smaller subunit that is found across all organisms.

### Step 3: Analyze the Options
The options provided are:
1. 13S
2. 14S
3. 15S
4. 16S

### Step 4: Relate the Options to Known Ribosomal Subunits
Among the options, the 16S rRNA is known to be a component of the 30S ribosomal subunit in prokaryotes. This 16S rRNA is considered universal because it is found in all prokaryotic organisms and is often used in phylogenetic studies to identify evolutionary relationships.

### Step 5: Conclusion
Based on the analysis, the universal smaller subunit of ribosomes is the **16S subunit**.

### Final Answer
The universal smaller subunit of ribosomes is **16S**.

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