Identify the features present in meiosis but absent in mitosis .

Options

A. Pairing of non-homologous chromosomes
B. Pairing of homologous chromosome and recombination between them
C. Disappearance of nucleoli
D. Replication of DNA

Answer

To identify the features present in meiosis but absent in mitosis, we can analyze the processes of both types of cell division. Here’s a step-by-step breakdown of the features:

### Step-by-Step Solution:

1. **Understanding Meiosis and Mitosis**:
- Meiosis is a type of cell division that reduces the chromosome number by half, resulting in the formation of gametes (sperm and eggs).
- Mitosis is a type of cell division that results in two identical daughter cells, maintaining the same chromosome number as the parent cell.

2. **Key Features of Meiosis**:
- **Pairing of Homologous Chromosomes**: During prophase I of meiosis, homologous chromosomes pair up in a process called synapsis. This is a critical feature of meiosis.
- **Recombination/Crossing Over**: While homologous chromosomes are paired, they can exchange genetic material through a process known as crossing over or recombination. This increases genetic diversity in the resulting gametes.

3. **Features Absent in Mitosis**:
- In mitosis, chromosomes do not pair with homologous partners; instead, they align independently at the metaphase plate.
- There is no crossing over in mitosis, as it is primarily focused on producing identical cells for growth and repair.

4. **Conclusion**:
- The features that are present in meiosis but absent in mitosis include:
- Pairing of homologous chromosomes.
- Recombination between homologous chromosomes.

### Final Answer:
The features present in meiosis but absent in mitosis are:
- Pairing of homologous chromosomes.
- Recombination (crossing over) between homologous chromosomes.