Which of the following two features are present in meiosis but absent in mitosis ?

Options

A. Pairing of non - homologous chromosome
B. Pairing of homologous chromosome and recombination between them
C. Replication of chromosome
D. All of these

Answer

To determine which two features are present in meiosis but absent in mitosis, we need to analyze the options provided:

1. **Understanding Meiosis and Mitosis:**
- **Mitosis** is a type of cell division that results in two identical daughter cells, maintaining the same chromosome number as the parent cell. It is primarily for growth and repair.
- **Meiosis**, on the other hand, is a specialized form of cell division that reduces the chromosome number by half, resulting in four genetically diverse gametes. It consists of two rounds of division: meiosis I and meiosis II.

2. **Analyzing the Options:**
- **A. Pairing of non-homologous chromosomes:** This is not a feature of either meiosis or mitosis. In meiosis, homologous chromosomes pair, not non-homologous ones.
- **B. Pairing of homologous chromosomes and recombination between them:** This is a key feature of meiosis. During prophase I of meiosis, homologous chromosomes pair up (a process called synapsis) and can exchange genetic material through recombination (crossing over).
- **C. Replication of chromosomes:** This occurs in both meiosis and mitosis before the actual division starts. Therefore, it is not exclusive to meiosis.
- **D. All of these:** This option cannot be correct as not all the features listed are present in meiosis.

3. **Conclusion:**
- The only option that describes features that are present in meiosis but absent in mitosis is **B. Pairing of homologous chromosomes and recombination between them**.

### Final Answer:
**B. Pairing of homologous chromosomes and recombination between them.**