1. The right answer is the fetus
Chorionic villi are another type of villi. They are part of the trophoblast, then of the placenta and allow the feeding of the fetus, and exchanges between the latter and the mother.
2. The right answer is maternal serum markers
Maternal serum markers are substances present in pregnant women that help to detect newborn chromosomal abnormalities such as down syndromes.
Current screening (see the legal framework for this screening) is based on the determination of substances present in the pregnant woman's blood, maternal serum markers, as well as the measurement of nuchal translucency.