What is the significance of meiosis :-

Options

A. The conservation of specific chromosome number of each species is achieved across ganerations in sexually reproducing organisms.
B. It increases the genetic variability in the population of organisms from generation to the next
C. Meiosis decreases the genetic variability in the population or organismss from one generation to the next
D. 1 and 2 option is correct

Answer

### Step-by-Step Solution:

1. **Definition of Meiosis**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in the formation of gametes (sperm and ovum).

2. **Reduction of Chromosome Number**: During meiosis, the diploid (2n) chromosome number is halved to haploid (n) in gametes. For example, if an organism has 46 chromosomes, meiosis will produce gametes with 23 chromosomes.

3. **Restoration of Chromosome Number**: Upon fertilization, when a sperm and ovum unite, the chromosome number is restored to the diploid state (2n). This ensures that the offspring have the same chromosome number as their parents.

4. **Conservation of Chromosome Number**: Meiosis helps in the conservation of the specific chromosome number of each species across generations in sexually reproducing organisms. This is crucial for maintaining species integrity.

5. **Genetic Variation**: During prophase I of meiosis, a process called crossing over occurs. This involves the exchange of genetic material between homologous chromosomes, leading to genetic recombination. This process increases genetic variability among offspring.

6. **Adaptability**: Increased genetic variability enhances the adaptability of organisms to changing environments. The more variations present, the better the chances of survival in different conditions.

7. **Conclusion**: The significance of meiosis includes the conservation of chromosome number and the promotion of genetic diversity, which are essential for evolution and adaptation.

### Final Answer:
The significance of meiosis lies in its role in reducing the chromosome number in gametes, conserving the species' chromosome number through generations, and increasing genetic variability through processes like crossing over, which enhances adaptability to environmental changes.