Final answer:
The genetically programmed series of stages from fertilization to adulthood in organisms is called development, beginning with the germinal stage and continuing through the embryonic and fetal stages.
Step-by-step explanation:
The series of genetically programmed stages that begins with sperm and eggs that fuse to become an embryo and eventually change into an adult is called development. This process encompasses multiple stages, starting with the germinal stage, where fertilization occurs and a zygote forms. The zygote undergoes cleavage, turns into a morula, then a blastocyst before implanting in the uterus. During the embryonic stage, the blastocyst develops into an embryo, undergoing significant transformations such as gastrulation, neurulation, and organogenesis, resulting in the formation of the three germ layers. This development continues into fetal stages, where growth and maturation prepare the organism for independent life outside of the womb.