From the following, identify the two correct statement with reference to meiosis.
I. Meiosis involves two sequential cycles of nuclear and cell division called meiosis I and meiosis II but only a single cycle of DNA replication.
II. Development of chiasmata occurs in diakinesis.
III. Separation of two basic sets of chromosomes.
IV. No division of centromere.

Options

A. II, III
B. II, IV
C. III, IV
D. I, III

Answer

To solve the question, we need to analyze each statement regarding meiosis and determine which two are correct.

### Step-by-Step Solution:

1. **Statement I: Meiosis involves two sequential cycles of nuclear and cell division called meiosis I and meiosis II but only a single cycle of DNA replication.**
- This statement is **correct**. Meiosis consists of two stages: meiosis I and meiosis II. During these stages, there is only one round of DNA replication that occurs before meiosis I.

2. **Statement II: Development of chiasmata occurs in diakinesis.**
- This statement is **incorrect**. Chiasmata, which are the points where homologous chromosomes exchange genetic material, develop during the diplotene stage of prophase I, not during diakinesis.

3. **Statement III: Separation of two basic sets of chromosomes.**
- This statement is **correct**. During anaphase I of meiosis, homologous chromosomes are separated, leading to the segregation of two sets of chromosomes.

4. **Statement IV: No division of centromere.**
- This statement is **incorrect**. The centromere does not divide during meiosis I; however, it does divide during meiosis II. Therefore, this statement is misleading.

### Conclusion:
The two correct statements regarding meiosis are:
- **I.** Meiosis involves two sequential cycles of nuclear and cell division called meiosis I and meiosis II but only a single cycle of DNA replication.
- **III.** Separation of two basic sets of chromosomes.