: If chemically nothing is ever created or destroyed but simply transformed, where does the matter come from when a sperm cell grows to a full body?

Question

I know obviously how the cell divides and becomes more and more complex over time. I get that the biological code is in the original cell, but where does the matter come from? In my mind, I imagine the first cell as an architect with all the blueprints, but without any material. It doesn’t pop out of nowhere, right?

In: Biology

Answer 1

During the very early stages of pregnancy the fetus gathers nutrients and “materials” from glands in the uterus. After around the two month mark, a placenta and umbilical cord form which then serve as the source of nutrients, though they are still gathered from the mother. This is also why pregnant women can have extremely specific cravings, their bodies are secreting hormones that make them crave things the fetus needs.