Match the columns and choose the right option
`{:(,"I",,"II",),(a.,"Leptotene",1.,"Terminalisation of chiasma",),(b.,"Zygotene",2.,"Crossing over and recombination",),(c.,"Pachytene",3.,"Synapsis",),(d.,"Diakinesis",4.,"Visibility of chromosomes.",):}`

Options

A. a-1, b-2, c-3, d-4
B. a-1, b-3, c-2, d-4
C. a-4, b-3, c-2, d-1
D. a-4, b-1, c-2, d-3

Answer

To solve the question of matching the phases of meiosis with their corresponding descriptions, we will analyze each phase and its characteristics step by step.

### Step-by-Step Solution:

1. **Identify the phases of prophase I of meiosis:**
- The phases are:
- A: Leptotene
- B: Zygotene
- C: Pachytene
- D: Diakinesis

2. **Match each phase with its description:**
- **Leptotene (A)**: This is the first stage of prophase I where chromosomes begin to condense and become visible.
- **Match**: 4. Visibility of chromosomes.

- **Zygotene (B)**: In this stage, homologous chromosomes begin to pair up, a process known as synapsis.
- **Match**: 3. Synapsis.

- **Pachytene (C)**: During this phase, crossing over occurs where non-sister chromatids exchange genetic material.
- **Match**: 2. Crossing over and recombination.

- **Diakinesis (D)**: This is the final stage of prophase I where the homologous chromosomes start to separate, and the chiasma becomes terminalized.
- **Match**: 1. Terminalization of chiasma.

3. **Compile the matches:**
- A (Leptotene) - 4 (Visibility of chromosomes)
- B (Zygotene) - 3 (Synapsis)
- C (Pachytene) - 2 (Crossing over and recombination)
- D (Diakinesis) - 1 (Terminalization of chiasma)

4. **Choose the correct option:**
- The correct matches correspond to the option: A4, B3, C2, D1.

### Final Answer:
The correct option is **A4, B3, C2, D1**.