A : Polyploids with odd number of chromosomes are prepagated vegetatively.
R : Seed formation is absent due to meiotic abnormality.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true and the reason is not the correct explanation of the assertion , then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

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

### Step 1: Analyze the Assertion
**Assertion (A):** Polyploids with odd number of chromosomes are propagated vegetatively.

- **Explanation:** Polyploids are organisms that have more than two complete sets of chromosomes. When we refer to polyploids with an odd number of chromosomes (like 3n, 5n, etc.), they cannot undergo normal meiosis effectively. This is because during meiosis, homologous chromosomes need to pair up, and an odd number of chromosomes makes it impossible for all chromosomes to find a partner. As a result, these polyploids cannot produce viable seeds and must be propagated vegetatively (through methods like cuttings, grafting, etc.).

### Step 2: Analyze the Reason
**Reason (R):** Seed formation is absent due to meiotic abnormality.

- **Explanation:** This statement is true because the meiotic process is crucial for the formation of gametes, which are necessary for seed formation. In polyploids with an odd number of chromosomes, the meiotic process is disrupted due to the inability to pair homologous chromosomes properly. This leads to meiotic abnormalities, resulting in no viable gametes and, consequently, no seed formation.

### Step 3: Determine the Relationship
- Both the assertion and reason are true statements.
- The reason (R) explains why the assertion (A) is true; the inability to form seeds due to meiotic abnormalities directly leads to the necessity of vegetative propagation in polyploids with odd numbers of chromosomes.

### Conclusion
Since both the assertion and reason are true, and the reason correctly explains the assertion, the answer is:
**Option 1:** Both A and R are true, and R is the correct explanation of A.

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