What is the main characteristic of a zygote?

A zygote is the initial cell formed when a female gamete (egg) fertilizes a male gamete (sperm). The primary characteristic of a zygote is that it contains a complete set of chromosomes, which is a total of 46 in humans. This is the result of the union of the 23 chromosomes from the sperm and 23 chromosomes from the egg, thereby restoring the diploid number that is characteristic of somatic cells. The zygote then begins to undergo a series of mitotic divisions to develop into an embryo.

In contrast, the other options do not accurately describe the zygote: it does not contain just 23 chromosomes, as it combines the genetic material from both parents. The zygote does not undergo meiosis, a process that reduces the chromosome number by half for the purpose of gamete production. Additionally, a zygote is not a form of connective tissue; rather, it is a reproductive cell that initiates the development of an organism.