Intricate, Complex Procedures

"Director Li, is that the XT80?" Han Meng was most interested in the XT80, since this gene-editing instrument would be used on him.

Director Li nodded. "Yes. Next, one of our researchers will demonstrate how to operate the XT80."

The researcher was already using the XT80 to conduct experiments. They did experiments every day.

The experimental sample was a human embryo cultured in vitro. It came from the human embryo storage room and was one of the million-strong army under Director Li's care.

The sample was on the thirteenth day of its life cycle, so it was referred to here as "it."

Once the sample reached the fourteenth day of development, international regulations required that its pronoun be changed to "he" or "she."

The fourteen-day rule meant that, in principle, biological experiments of any kind could only be performed on human embryos no more than fourteen days old.

International organizations considered a fertilized egg that had developed for fourteen days to be a morally mature human being.

At thirteen days of development, "it" was tiny: a sac-like object only a few millimeters in diameter. "It" was filled with fluid. Its ectoderm would develop into the epidermis, nails, hair, teeth, sensory organs, and nervous system; its endoderm would develop into the digestive system, liver, pancreas, salivary glands, and respiratory system; and its mesoderm would become the dermis, muscles, tendons, circulatory system, and excretory system.

"This sample has an extra copy of chromosome 21," Director Li explained as the demonstration proceeded, concise and precise, getting straight to the point.

"Oh." Han Meng watched the experiment closely. Its details appeared on the computer screen connected to the XT80.

Humans had two sets of chromosomes, forty-six in all. The extra chromosome in the sample was clearly abnormal.

Of fertilized eggs with an extra copy