Final answer:
During meiosis, the number of chromosomes is precisely haploid (n), leading to the production of unique gametes. Upon fertilization, two haploid gametes unite to form a diploid zygote, restoring the diploid number of chromosomes.
Step-by-step explanation:
During the formation of gametes (meiosis), the number is precisely haploid (n), and when the two gametes combine during fertilization, the diploid number is reestablished. The process of meiosis ensures that each gamete has a single set of chromosomes (n). In humans, where n = 23, this phenomenon can result in over 8 million different combinations due to the random assortment of chromosomes during metaphase I. When a haploid sperm and a haploid egg combine, a diploid zygote is formed (2n), with half the DNA coming from each parent, which then undergoes multiple rounds of mitosis to produce a multicellular offspring.
During the formation of gametes through meiosis, the chromosome number becomes precisely haploid (n), representing half the diploid number. In humans, where the diploid number is 46, the haploid number is 23. Meiosis ensures that each gamete receives a single set of chromosomes, containing a diverse combination due to the random assortment during metaphase I. This process results in over 8 million possible chromosomal combinations in human gametes.
Upon fertilization, when a haploid sperm and a haploid egg combine, a diploid zygote is formed (2n), restoring the diploid chromosome number. The zygote inherits half of its DNA from each parent. Subsequently, the zygote undergoes multiple rounds of mitosis, a process of cell division, leading to the development of a multicellular organism with each cell maintaining the diploid chromosomal complement. This intricate series of events ensures genetic diversity and stability in the reproduction of sexually reproducing organisms.