gonadal differentiation begins at approximately what point after conception
Sexual differentiation in humans As the zygote divides, it first becomes the embryo (which means 'growing within'), typically between zero and eight weeks, then from the eighth week until birth, it is considered the fetus (which means 'unborn offspring'). The internal genitalia are all the accessory glands and ducts that connect the gonads to the outside environment. The external genitalia consist of all the external reproductive structures. The sex of an early embryo cannot be determined because the reproductive structures do not differentiate until the seventh week. Prior to this, the child is considered bipotential because it cannot be identified as male or female.
Cell potency The human development model is one which can be used to describe how totipotent cells arise.[9] Human development begins when a sperm fertilizes an egg and the resulting fertilized egg creates a single totipotent cell, a zygote.[10] In the first hours after fertilization, this zygote divides into identical totipotent cells, which can later develop into any of the three germ layers of a human (endoderm, mesoderm, or ectoderm), into cells of the cytotrophoblast layer or syncytiotrophoblast layer of the placenta. After reaching a 16-cell stage, the totipotent cells of the morula differentiate into cells that will eventually become either the blastocyst's Inner cell mass or the outer trophoblasts. Approximately four days after fertilization and after several cycles of cell division, these totipotent cells begin to specialize. The inner cell mass, the source of embryonic stem cells, becomes pluripotent.