WJEC Biology Practice Exam

In meiosis, a form of cell division that occurs in sexually reproducing organisms, the process reduces the chromosome number by half. This is essential for maintaining the species' chromosome number across generations when gametes (sperm and eggs) fuse during fertilization.

During meiosis, a diploid parent cell (which has two sets of chromosomes, one from each parent) undergoes two rounds of division: meiosis I and meiosis II. In meiosis I, homologous chromosomes are separated, leading to two daughter cells that each have half the original number of chromosomes. Then, meiosis II separates the sister chromatids of each chromosome, resulting in four genetically distinct daughter cells at the end of the process.

Each of these daughter cells contains only one set of chromosomes, which corresponds to half the number of chromosomes present in the original diploid parent cell. This halving is crucial as it ensures that when fertilization occurs, the resulting zygote restores the diploid number of chromosomes. Therefore, the daughter cells produced by meiosis indeed contain half the amount of chromosomes compared to the parent cell, making this the correct understanding.