Which statement describes a key difference between meiosis and mitosis
The Correct Answer and Explanation is :
A key difference between meiosis and mitosis is that meiosis produces four genetically distinct daughter cells, while mitosis produces two genetically identical daughter cells.
Explanation:
Mitosis and meiosis are both forms of cell division but serve different purposes and involve distinct processes.
Mitosis is a type of somatic (body) cell division that results in the replication of a cell’s genetic material and the distribution of identical sets of chromosomes to two daughter cells. This process is crucial for growth, development, and tissue repair in multicellular organisms. The phases of mitosis—prophase, metaphase, anaphase, and telophase—ensure that each daughter cell receives a complete set of chromosomes. Each daughter cell is genetically identical to the parent cell and to each other, maintaining the same chromosome number as the original cell (diploid in humans, for instance).
Meiosis, on the other hand, is a specialized form of cell division that occurs only in the formation of gametes—sperm and egg cells. It consists of two successive divisions: meiosis I and meiosis II. During meiosis I, homologous chromosomes are separated, and genetic recombination occurs through processes like crossing over, which increases genetic diversity. As a result, meiosis produces four non-identical daughter cells, each with half the number of chromosomes of the original cell (haploid). This reduction is vital for sexual reproduction, ensuring that when gametes fuse during fertilization, the resulting zygote has the correct diploid chromosome number.
In summary, the main distinction lies in the outcomes of these processes: mitosis yields two genetically identical cells, while meiosis produces four genetically diverse cells, essential for genetic variation in sexually reproducing organisms. This variation is crucial for evolution and adaptability in changing environments.