The correct answer is: D. All of the above
Meiosis is a type of cell division that results in four daughter cells each with half the number of chromosomes as the parent cell. It is responsible for the production of gametes (sex cells) in sexually reproducing organisms.
Meiosis consists of two rounds of cell division, meiosis I and meiosis II. Meiosis I is similar to mitosis in that the chromosomes replicate and the cell divides into two daughter cells. However, there are also some important differences. In meiosis I, the homologous chromosomes pair up and undergo crossing over, which is a process that results in the exchange of genetic material between the chromosomes. This increases genetic diversity.
Meiosis II is similar to mitosis in that the chromosomes segregate into daughter cells. However, there is no replication of DNA between meiosis I and meiosis II. This means that the daughter cells of meiosis II have half the number of chromosomes as the parent cell.
The following table summarizes the similarities and differences between meiosis I and mitosis:
| Characteristic | Meiosis I | Mitosis |
| — | — | — |
| Number of rounds of division | 2 | 1 |
| Replication of DNA | Yes | No |
| Segregation of chromosomes | Yes | Yes |
| Number of daughter cells | 4 | 2 |
| Chromosome number in daughter cells | haploid | diploid |
Meiosis is essential for sexual reproduction because it allows for the production of gametes with half the number of chromosomes as the parent cell. This is necessary for the fusion of gametes during fertilization, which results in a zygote with the full number of chromosomes.