Meiosis is the process that produces haploid cells from a diploid cell.
Understanding Meiosis and Ploidy
Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half to produce four daughter cells. This is crucial for sexual reproduction. The starting cell is diploid, meaning it has two sets of chromosomes (one from each parent). Through two rounds of division (Meiosis I and Meiosis II), these chromosomes are separated, resulting in four haploid daughter cells. Each haploid cell contains only one set of chromosomes. When these haploid cells (gametes—sperm and egg cells) fuse during fertilization, the resulting zygote is once again diploid.
- Diploid (2n): Cells containing two complete sets of chromosomes. Most somatic (body) cells are diploid.
- Haploid (n): Cells containing only one set of chromosomes. Gametes (sex cells) are haploid.
The provided YouTube video, "3.3 Meiosis - Diploid Versus Haploid," further clarifies this process, showing the reduction in chromosome number during meiosis. The video highlights that while sister chromatids separate in Meiosis II, this doesn't change the haploid state because the sister chromatids were part of the same chromosome. Other resources such as the Nature Scitable article on meiosis ("meiosis | Learn Science at Scitable") reinforce that meiosis results in four haploid daughter cells from a diploid parent cell. The fact that gametes are haploid ("Haploid") and that diploid cells produce haploid gametes through meiosis ("What are Haploid and Diploid Cells? - YouTube") are also crucial aspects highlighted in the references.
Therefore, while the process begins with a diploid cell, the outcome of meiosis is haploid cells.
