Which of the following chromosomes are called diplotene chromosomes :-

Options

A. Polytene chromosomes
B. Super numerary chromosomes
C. Sex chromosomes
D. Lamp brush chromosomes

Answer

To determine which chromosomes are referred to as diplotene chromosomes, we will analyze the provided options step by step.

### Step 1: Understand the term "diplotene chromosomes"
- Diplotene chromosomes are a specific stage of chromosomes observed during meiosis, particularly in prophase I. They are characterized by the separation of homologous chromosomes that were previously paired during the zygotene stage.

### Step 2: Analyze the options
1. **Polytene chromosomes**:
- These are giant chromosomes formed by repeated rounds of DNA replication without cell division. They are not diplotene chromosomes.
- **Hint**: Think about the structure and formation of polytene chromosomes.

2. **Supernumerary chromosomes**:
- These are extra chromosomes that can occur in some organisms. They do not specifically refer to diplotene chromosomes.
- **Hint**: Consider the definition of supernumerary chromosomes and their role in genetics.

3. **Sex chromosomes**:
- Also known as allosomes, these chromosomes determine the sex of an organism. They are not classified as diplotene chromosomes.
- **Hint**: Recall the function of sex chromosomes in determining gender.

4. **Lambrusch chromosomes**:
- This term is often used interchangeably with diplotene chromosomes. They represent the stage where homologous chromosomes are partially separated but still connected at chiasmata.
- **Hint**: Remember the specific stage of meiosis where lambrusch chromosomes are found.

### Step 3: Conclusion
- Based on the analysis, the correct answer is **Lambrusch chromosomes**, which are indeed referred to as diplotene chromosomes.

### Final Answer:
**The chromosomes called diplotene chromosomes are Lambrusch chromosomes (Option 4).**