In oocytes, which of the following phase can last for months or years, since it is at this stage the chromosomes decondense and engage in RNA synthesis?
(a) Diakinesis
(b) Diplotene
(c) Pachytene
(d) Leptotene

Options

A. Diakinesis
B. Diplotene
C. Pachytene
D. Leptotene

Answer

To solve the question regarding which phase in oocytes can last for months or years, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which phase in oocytes lasts for an extended period and is characterized by chromosome decondensation and RNA synthesis.

2. **Identify the Phases**: The options provided are:
- (a) Diakinesis
- (b) Diplotene
- (c) Pachytene
- (d) Leptotene

3. **Recall Oocyte Development**: Oocytes undergo several stages during meiosis, and it is essential to know what happens in each phase:
- **Leptotene**: Chromosomes begin to condense.
- **Pachytene**: Homologous chromosomes pair up and exchange genetic material (crossing over).
- **Diplotene**: Chromosomes start to decondense, and RNA synthesis occurs. This phase can last for an extended period, sometimes years.
- **Diakinesis**: Chromosomes condense further and prepare for metaphase.

4. **Focus on the Key Characteristics**: The question specifies that the phase involves chromosome decondensation and RNA synthesis. This is a critical clue.

5. **Analyze the Options**:
- **Diakinesis**: Not the correct answer as it is a preparatory phase for metaphase.
- **Diplotene**: Correct answer, as it is known to last for months or years and involves decondensation and RNA synthesis.
- **Pachytene**: Involves crossing over but does not last as long as diplotene.
- **Leptotene**: Early stage of chromosome condensation.

6. **Conclusion**: Based on the analysis, the phase that can last for months or years, where chromosomes decondense and RNA synthesis occurs, is **Diplotene**.

### Final Answer:
(b) Diplotene