Choose the incorrect statement w.r.t ribosome.

Options

A. It is composed of rRNA and proteins
B. It is not surrounded by any membrane
C. It is the smallest cell organelle
D. It helps in lipid synthesis

Answer

To determine the incorrect statement regarding ribosomes, we will analyze each option provided in the question step by step.

### Step 1: Understand the Structure of Ribosomes
Ribosomes are cellular structures that are not membrane-bound. They are composed of ribosomal RNA (rRNA) and proteins. This is an important characteristic of ribosomes.

**Hint:** Remember that ribosomes are made of RNA and proteins and are not surrounded by a membrane.

### Step 2: Identify Ribosome Types in Different Cells
Ribosomes can be found in both prokaryotic and eukaryotic cells. The key difference is in their size: prokaryotic ribosomes are 70S, while eukaryotic ribosomes are 80S.

**Hint:** Recall the distinction between prokaryotic and eukaryotic ribosomes based on their sedimentation rates (Svedberg units).

### Step 3: Function of Ribosomes
The primary function of ribosomes is protein synthesis. They translate messenger RNA (mRNA) into polypeptide chains, which then fold into functional proteins.

**Hint:** Focus on the role of ribosomes in protein synthesis, as this is their main function.

### Step 4: Analyze the Statements
Now, we will evaluate the statements one by one:

1. **Statement about ribosomes being found in both prokaryotic and eukaryotic cells** - This is correct.
2. **Statement about ribosomes being made of RNA and proteins** - This is also correct.
3. **Statement about ribosomes not being surrounded by a membrane** - This is correct as well.
4. **Statement about ribosomes helping in lipid synthesis** - This is incorrect. Ribosomes do not synthesize lipids; that function is performed by other organelles, such as smooth endoplasmic reticulum or spherosomes.

### Conclusion
Based on the analysis, the incorrect statement regarding ribosomes is the one that claims they help in lipid synthesis.

**Final Answer:** The incorrect statement is that ribosomes help in lipid synthesis.