Final answer:
Conception is the fertilization of an ovum by a sperm to form a zygote. Implantation is when the blastocyst attaches to the uterus wall, progressing the zygote to the embryonic stage. The embryo develops into a fetus, which continues to grow and mature until birth.
Step-by-step explanation:
Conception, implantation, and development of the embryo and fetus are critical stages in human development. During conception, a sperm fertilizes an ovum in the Fallopian tube, forming a zygote. This stage, also known as the germinal stage, involves the zygote undergoing cell divisions to form a ball of cells called a morula, and then a blastocyst. Implantation occurs when the blastocyst attaches to the uterus wall, marking the end of the germinal stage and the beginning of the embryonic stage.
Post-implantation, the embryonic development phase lasts through the eighth week following fertilization. During this period, the embryo grows and becomes more complex, forming most organs and developing specialized cells and tissues. After this stage, from the ninth week of gestation until birth, the embryo is referred to as a fetus. It experiences further growth and development, with organ systems maturing enough to function after birth.
The term in the question that is not involved in conception, implantation, and development of the embryo and fetus is not provided, thus we cannot identify the irrelevant term.