which of the following statement is incorrect w.r.t ribosomes?

Options

A. The type of ribosomes of prokaryotes is 70S
B. Ribosomes were descoverd by George Palade
C. They are made up of RNA only
D. Ribosome are also known as protein factories

Answer

To determine which statement is incorrect with respect to ribosomes, we can analyze the given options based on our knowledge of ribosomes. Here’s a step-by-step solution:

### Step 1: Understand the Structure of Ribosomes
Ribosomes are cellular organelles that play a crucial role in protein synthesis. They are composed of ribonucleic acid (RNA) and proteins.

**Hint:** Remember that ribosomes are made of both RNA and proteins, not just one of them.

### Step 2: Identify Ribosome Types in Different Organisms
Ribosomes are found in both prokaryotic and eukaryotic cells. In prokaryotes, ribosomes are classified as 70S, which consists of a 50S large subunit and a 30S small subunit.

**Hint:** Recall the sedimentation coefficient (S) that indicates the size of ribosomal subunits.

### Step 3: Review Historical Context
Ribosomes were first discovered by George Palade, a notable scientist in cell biology.

**Hint:** Think about the key figures in biology who contributed to the discovery of cellular structures.

### Step 4: Evaluate Each Statement
1. **Statement 1:** "The type of ribosome of prokaryotes is 70S." - This is correct.
2. **Statement 2:** "Ribosomes were discovered by George Palade." - This is correct.
3. **Statement 3:** "They are made up of RNA only." - This is incorrect because ribosomes are made up of both RNA and proteins.
4. **Statement 4:** "Ribosomes are also known as protein factories." - This is correct.

**Hint:** Look for the statement that contradicts the established facts about ribosomes.

### Step 5: Conclusion
The incorrect statement with respect to ribosomes is: "They are made up of RNA only."

**Final Answer:** The incorrect statement is that ribosomes are made up of RNA only.