$ Cyanobacterial cells are eukaryotic
! Prokaryotic cells are diploid.

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 question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states: "Cyanobacterial cells are eukaryotic."
- Cyanobacteria, also known as blue-green algae, are actually classified as prokaryotic organisms. They lack a true nucleus and membrane-bound organelles, which are characteristic features of eukaryotic cells. Therefore, this assertion is **false**.

### Step 2: Analyze the Reason
The reason states: "Prokaryotic cells are diploid."
- Prokaryotic cells, such as bacteria, typically have a single circular chromosome and are usually **haploid** (having one set of chromosomes). They do not possess a diploid state like eukaryotic cells. Thus, this reason is also **false**.

### Step 3: Determine the Relationship
Now we need to determine the relationship between the assertion and the reason:
- Since both the assertion and the reason are false, the correct option would be that both are incorrect.

### Conclusion
Based on the analysis:
- The correct answer is **D: Both assertion and reason are incorrect**.

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