Embryology textbook quote: Keith Moore and T.V.N. Persaud's 'The Developing Human' — a zygote is the beginning of a new human being

Mike cites 'The Developing Human: Clinically Oriented Embryology' by Keith Moore and T.V.N. Persaud. The quote states: 'A zygote is the beginning of a new human being. Human development begins at fertilization, the process during which a male gamete or sperm unites with a female gamete or oocyte to form a single cell called a zygote. This highly specialized, totipotent cell marks the beginning of each of us as a unique individual.' Mike notes that zygote is the earliest developmental stage, analogous to how 'infant' and 'toddler' refer to specific developmental ages.