As :Endoplasmic reticulum also acts as the cell-skelton.
R:Flagellum of a prokaryotic cell is formed of a protein called Tubulin.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the assertion and reason question, we will analyze both statements step by step.

### Step 1: Analyze the Assertion
The assertion states: "Endoplasmic reticulum also acts as the cell-skeleton."
- The endoplasmic reticulum (ER) is indeed a network of membranes that extends throughout the cytoplasm of the cell.
- It provides structural support and helps maintain the shape of the cell, similar to a skeleton.
- Therefore, the assertion is **correct**.

### Step 2: Analyze the Reason
The reason states: "Flagellum of a prokaryotic cell is formed of a protein called Tubulin."
- In prokaryotic cells (like bacteria), the flagellum is made of a protein called **flagellin**, not tubulin.
- Tubulin is the protein that makes up the microtubules in eukaryotic cells, which are found in structures like cilia and eukaryotic flagella.
- Therefore, the reason is **incorrect**.

### Step 3: Determine the Relationship
Now we need to determine if the reason correctly explains the assertion:
- The assertion is correct, but the reason is incorrect.
- Since the reason does not explain or relate to the assertion, we conclude that the correct relationship is that the assertion is true while the reason is false.

### Conclusion
Based on the analysis:
- The assertion is correct.
- The reason is incorrect.
- Therefore, the correct answer is **Option C: Assertion is correct, reason is wrong**.

---