Life Cycle of a Primate is elementary science.
I will assume that you are referring to human life: Most biologist say that life begins at fertilization, when a sperm penetrates and egg allowing it to form a zygote which will continue to grow and divide and differentiate--assuming that it implants properly and...
Twenty lashes with a wet noodle for you both, and a remedial reread of
The Foundation Trilogy. Let's all say it together: "A circle has no end."
Science is not what it says in an elementary science textbook, nor is it what most biologists say, because textbooks and majorities are
authorities, and science is not a matter of authority -- it's a matter of falsifiable theories tested against observation. The claim "Life begins at fertilization" has no observable implications different from what "Life begins at ovulation" or "Life begins at quickening" or "Life begins at puberty" imply. Therefore it is not a scientific claim. The thing to remember about a life cycle is that
it's a cycle. The stages of a cycle go around and around in a circle. A circle has no end and no beginning. Claiming any particular point in a cycle is "the beginning" is an exercise in labeling, not an exercise in making a testable prediction.